JPH0277043A - Multi-division photometry device in external photometry system and camera provided therewith - Google Patents

Abstract

PURPOSE:To keep photometric distribution characteristic constant by deciding weight given to the photometric value of a photometry means and obtaining the weighted average of the photometric value of the respective photometry means. CONSTITUTION:A microcomputer 1 decides a lens stop point in accordance with the photographic distance of an object based on plural range-finding data Z. Thereafter, the microcomputer 1 performs exposure operation based on the plural range-finding data Z, the lens stop point and the plural photometric data Bv, etc., so as to obtain the control data of a shutter and a flash. Therefore, since the weight given to each photometric datum is decided based on the information concerning the focal distance of a photographic lens, the range of photometry is apparently changed with the change of photographic viewing angle. Thus, even if the photographic viewing angle is changed, the photometric distribution characteristic can be kept constant even in an external photometry system as well as a TTL system.

Description

[Detailed description of the invention]

[Field of the Invention] This invention relates to an external photometry type photometry device, and in particular,
The present invention relates to a multi-segment photometry device that performs photometry by dividing a field into a plurality of areas. Confused! Tsukishizuri - Conventionally, in order to find the appropriate exposure value, the subject is divided into multiple snow areas and photometered individually, and a weighted average value is calculated by giving a predetermined weight to each photometric data. Cameras that control exposure based on this have been proposed. For example, Japanese Patent Application Laid-Open No. 62-35327 states that the weighting given to each photometric value is based on the AF mode, maximum brightness, minimum brightness, brightness difference, subject distance, river fish distance of the L & shadow lens, etc. has been shown to change. Also, JP-A-6
No. 1-279829 discloses changing the weight given to each photometric value depending on the image magnification. By the way, in a TTL photometer that measures the light that has passed through the photographic lens, the photometry range changes as the angle of view changes, so the size of the photometry range that occupies the photographic range is is always kept constant. Therefore, there is an advantage that the photometric distribution characteristics do not change even if the photographing angle of view changes. On the other hand, with external metering type photometers, the photometry range does not change even if the shooting angle of view changes, so the size of the photometry range that occupies the shooting range changes depending on the change in the shooting angle of view. Photometric distribution characteristics cannot be kept constant. For example, when wide-angle [j], the metering range occupies a large part of the shooting range! This results in a center-weighted photometric distribution characteristic. On the contrary, 5. During telephoto shooting, the metering range occupies a larger portion of the shooting range, and sometimes
The metering range may be larger than the shooting range. Therefore, during telephoto shooting, the photometric distribution characteristics will be average. This invention improves the above-mentioned disadvantages of external photometry type photometers, and provides an external photometry type multi-segment photometry device that can maintain constant photometry distribution characteristics even when the shooting angle of view changes. is intended to provide. In order to achieve this objective, the multi-segment photometry device of the present invention includes a center photometry means for photometering an area approximately in the center of the field and outputting center photometry data; A multi-segment photometry device using an external photometry method, which is equipped with a peripheral photometer that measures the peripheral area of the lens and outputs peripheral photometry data, and a focal length information input device that inputs information regarding the focal length of the photographic lens. an input means, a weight determining means for determining the weight to be given to the photometric value of each photometric means based on information regarding the focal length of the photographic lens, and a weighted average of the photometric values of each photometric means based on the determined weights. The invention is characterized in that it is equipped with arithmetic means for calculating. In the external photometry type multi-segment photometry device having the above configuration, the weight given to the photometry value of each weather measurement means is determined according to the focal length of the photographing lens. Collectively, the focal length of the photographic lens is long (indeed, the center photometry data is given a large weight.As a result, although the appearance is good, the photometry range changes as the photographic angle of view changes. In a camera equipped with the above-mentioned photometric device, exposure is controlled based on a weighted average value of each photometric data.The camera implementing the present invention will be explained with reference to the drawings. This camera can switch the focal length of the lens (38m+a, 80mm), and
Telephoto shooting with a teleconverter (focal length 105
This is a camera that can perform [Overall Configuration 1 FIG. 1 is an overall block diagram of a camera embodying the present invention. In the figure, numeral 1 denotes a micro combinator (hereinafter abbreviated as microcomputer), which controls the entire camera. Reference numeral 2 denotes a main switch determining means, which outputs a signal S, , to the microcomputer 1 when a main switch (not shown) is ON. This signal S. Shooting is possible when is being output. 3 is a release signal generating means, and when a release button (not shown) is pressed down to the first stroke, a signal S is generated.
When the release button is pressed down to a second stroke, which is better than the first stroke, a signal S2 is output. Therefore, when the signal $2 is being output, the signal Sl is always being output. As will be described later, when the microcomputer 1 receives the signal S, it starts photometry and distance measurement operations,
When the signal S2 is input, a photographing operation is performed. 4 is a forced light emission signal output means, which outputs a signal Sf1 when a strong III light emission switch (not shown) is ON. As will be described later, when the microcomputer 1 inputs the signal Srl, the microcomputer 1 always uses 7 rays of light regardless of the brightness of the subject. Fire the i16 to take a picture (flash photography). Reference numeral 5 denotes a light emission prohibition signal output means, which outputs No. 43 SnN when a light emission prohibition switch 7 (not shown) is ON. As will be described later, when the microcomputer 1 receives the signal 5oil, the microcomputer 1 always performs photography (natural light photography) without causing the 7-lash device 16 to emit light, regardless of the brightness condition of the scene. Reference numeral 6 denotes a focal length switching signal output means, which outputs a pulsed focal length switching signal Sst in synchronization with a focal length switching switch (not shown) being turned on. When the microcomputer 1 receives this signal Sst, it outputs a focal length switching signal 18.
It sends a signal to switch the focal length of the photographing lens, and outputs the signal y to the flash light distribution switching means 17. Each of the switching means 17, 18, and 19 is constituted by a well-known means, so a description thereof will be omitted.
The pulse width of the signal Sst is shorter than the time required for these switches, but is set to a somewhat longer time (for example, 0.1 seconds). Reference numeral 7 denotes a teleconverter detection means, which outputs a mounting signal Stc when a teleconverter is mounted on the camera. Reference numeral 8 denotes a back cover opening/closing detection means, which outputs a signal Sback indicating whether or not the back cover (not shown) is closed. As will be described later, when the microcomputer 1 detects that the reverse side has changed from the open state to the open state, it outputs a signal to the film winding means 20 to perform initial loading of the film. Reference numeral 9 denotes a rewind signal output means, which outputs a rewind signal Srw when the film reaches the final frame or when a rewind switch (not shown) is turned on. As will be described later, when the microcomputer 1 receives the signal Srw, it outputs a signal to the film rewind: f = stage 2J to cause the film to be rewinded. The switches (not shown) provided in each of the above means 2 to 6 and 9 are not limited to mechanical switches, but are M'A switches (for example,
touch switch), optical (e.g. 7 otocoupler)
v. Any type of switch may be used in the 5M configuration, and each detection by the teleconverter detection means 7. Any electrical method may be used, such as an optical method using a 7-oto coupler or the like. A film sensitivity reading means 10 reads the film sensitivity from a DX hood formed on the cartridge, converts it into an APEX value, and outputs film sensitivity information Sv to the microcomputer 1. Further, the film sensitivity reading means 10 has a manually operated member, and the film sensitivity information Sv to be output can be changed according to the intention of the person in the shadow. Reference numeral 11 denotes a charging detection means, which determines that the charging voltage of a main capacitor (not shown) in the 7-ray device 16 is the voltage (for example, 300V) required to emit 7-ray light.
It is detected whether the charging voltage of the main capacitor has reached this level, and if the charging voltage of the main capacitor has reached a voltage that allows 7 lashes to be emitted, a charging completion signal See is output. 12 is a distance measuring means, which receives a control signal C from the microcomputer 1.
Based on TRL, the photographing distance of the subject within a plurality of distance measurement areas within the photographic screen is measured, and distance measurement data Z is output. Reference numeral 13 denotes an external light type photometry means, which measures the brightness of a subject within a plurality of photometry zones within the photographic screen based on a control signal CTRL2 from the microcomputer 1, and outputs photometry data By. These two means 12.13 will be described in more detail later. Reference numeral 14 denotes a lens driving means, which drives the lens based on data output from the microcomputer 1 and performs focus adjustment. 15 is a shutter driving means, which opens and closes a shank (not shown) which also serves as an aperture blade, based on a signal output from the microcomputer 1. The flash unit R116 emits 7 flashes in response to the signal Sx from the microcomputer 1, and is boosted! il
In response to the I signal Sad, a booster circuit (not shown) is controlled. Note that each of the means 14 to 21 is a well-known -F stage, so a detailed explanation will be omitted. [Overall Control 1] Next, the operation of the microcomputer 1 will be explained. FIG. 2 is a 7rj-chart showing the operation of the microcomputer 1. When the power is turned on, the microcomputer 1 starts operating according to this 70-chart. First, the microcomputer 1 checks whether the rewind signal Srw is output (C#10), and if the rewind signal Srw is output, the process goes to #11, and if the signal Srw is not output, the process goes to #15. Proceeding to #11, the microcomputer 1 outputs the boost control signal Sdd to stop charging the main capacitor, and stops the operation of the boost circuit. Thereafter, a signal is output to the film rewinding means 21 to cause the film to be rewinded (#12), and the process returns to #10. Proceeding to #15, the microcomputer 1 checks whether the rear lid is open or closed, and if the JX lid is open, it advances to #20, and if the rear lid is closed, it advances to #16. In #1G,
Microcomputer 1 is the back of last time' ζtanor! The RrR status is checked, and if the back cover was opened last time, it is determined that the back cover has just been closed, and the process proceeds to #17. Otherwise#
Proceed to 20. 1 in #17, microcontroller 1 in #11
Similarly, the external pressure is stopped, the process proceeds to #18, a signal is output to the film winding means 20 to perform initial loading of the film, and then the process returns to #10. When proceeding to #20, the microcomputer 1 checks the state of the main switch, and if the signal S is output, the process proceeds to #21; if the signal S is not output, the process proceeds to step 28. In #21, the microcomputer 1 checks whether a teleconverter is installed. If the signal SLc is output, the process proceeds to #22; if the signal SLe is not output, the process proceeds to #2.
Proceed to step 3. In #22, the microcomputer 1 separates the focal length of the photographic lens by tq, and if the focal length is on the short focal length (38 nua) side, the process proceeds to #24, and if the focal length is on the long focal length (80 m+*) side, the process proceeds to #26. As described above, in the camera of this embodiment, when the teleconverter is attached, the focal length of the photographing lens is always set to the long focal length (80a++*) side (as described later, proceed to #24). and the focal length of the lens is switched in #25). by the way,
In short focal length photography, the angle of view is wider than in long focal length photography, so if you attach a teleconverter, part of the screen may be vignetted. However, the camera of this embodiment uses 5! teleconverters! When c′Xj,
Since it is always set to long focal length shooting, there is no vignetting caused by the teleconverter. In #23, the microcomputer 1 checks the state of the focal length changeover switch (not shown), and if the signal Sst is output, the microcomputer 1 selects #2.
The process proceeds to #4, and if the signal Sst is not output, the process proceeds to #2G. Proceeding to well 24, microcomputer 1, like #11,
Stop pressurization. After that, proceed to #25 and proceed to [Microcomputer]
are a flash light distribution switching means 17 and an allegory distance switching means 1.
8. Output a signal to the lighting switching means 19 to switch between flash light distribution, focus, distance, and lighting. Thereafter, the microcomputer 1 returns to #10 and continues processing. In addition, as mentioned above, at this time, the signal Sst is >+'r
Even if you turn on the focal length switch,
Even if you continue to do so, the focal length switching operation will not be performed continuously. A flag (for convenience, referred to as Fqt) that is set immediately after switching the focus y distance history is provided, and the stirring 23
On the way from #24, it is determined whether 7-lag FsL is set, and if 7-lag Fst is set, #24. You may omit #25 and skip to #10, and if the 7 lag Fst is not set (just 1!), you may proceed to #24 after setting the 7 lag Fst.At this time, the signal Sst is output in #23. If not,
Proceed to #26 after 7 lag Fst recency. In this case, the focal length switching signal output means 6 may continue to output the signal SsL while the focal length switching switch (not shown) is ON. In step 26, the microcomputer 1 checks whether the signal S1 is being output;
Proceed to step 30, and if signal Sl is not output, go to #27
Proceed to. In #27, the microcomputer 1 checks the charging state of the main capacitor, and if the charging of the main capacitor is completed and No. 43 See is output, the process proceeds to #28, and the signal See is output without charging being completed. If it is not output, proceed to step #2. In #28, the microcomputer 1 stops boosting the voltage as in #11, and then returns to #10. In #29, microcontroller 1
In order to activate the external pressure circuit and charge the main capacitor, (W No. S dd is fully output, and then,
Return to #10. In stirring 26, when it is detected that the signal Sl has been output, that is, the release button (not shown) has been pressed down to the PJ1 stroke, and the process proceeds to #30, the microcomputer 1
After stopping the external pressure, proceed to #32. At #32, the microcomputer 1 checks and stores the states of the forced light emission switch and the light emission prohibition switch (not shown), and proceeds to #34. As will be described later, in the camera of this embodiment, it is determined whether or not the flash prohibition signal SnN is output before the forced flash signal Sfl (see figure PtS18).
If the photographer mistakenly turns on the forced flash switch and the flash prohibition switch (not shown) at the same time, the result will be natural light photography. , daytime synchronized shooting, etc.
Since it is more common to take pictures with the -7 flash flash forced on, if both signals Sfl and 5nfl are being output, the photographer should set the flash prohibition switch when selecting the forced flash mode. It is assumed that it has been turned on by mistake, and only the forced flash signal Srl is output, and the flash prohibition signal 5nrl is output.
The states of the forced light emission switch and the light emission prohibition switch may be stored with the assumption that they are not being output. At #34, the microcomputer 1 inputs film sensitivity information Sv from the film sensitivity reading means 10. Then, proceed to #36 to perform photometry and distance measurement operations, and #3
Proceed to step 8. In #38, the microcomputer 1 determines a lens stop point Zs according to the shooting distance of the subject based on the plurality of distance measurement data Z. Thereafter, the microcomputer 1 proceeds to #40, performs exposure based on a plurality of distance measurement data Z, a lens stop point, a plurality of photometry data By, etc., and obtains control data for the shutter and 7 ratunyu. In addition, the above 3
Steps #36, #38, and #40 (Proceed in detail in step #40. After completing the exposure calculation in step #40, microcomputer 1 needs to fire the flash based on the calculation result. ($50).If it is necessary to fire the flash, the microcomputer 1 proceeds to #52 to check the state of charge of the main capacitor, and if the main capacitor has been fully charged, the microcomputer 1 proceeds to #52. After proceeding to #54 and stopping the boost operation (t, proceed to #56. Conversely, if the charging of the main capacitor has not been completed, the microcomputer 1 proceeds to #53 and starting the boost operation, and then # Proceed to step 58 (that is, prohibit the shirt release when the battery is not fully charged). Note that an unfilled warning may be issued after step 53. On the other hand, if the flash is not required in #50, , Microcomputer 11 Sat #5
Proceed to 6 6 At #56, the microcomputer 1 checks whether the signal S2 is being outputted, that is, whether the photographer has pressed the release button (not shown) to the second stroke and made the shooting operation slow! Set. If signal S2 is not output,
The microcomputer 1 proceeds to #60 and performs a photographing operation. In #56, if the signal S2 is not output, the microcomputer 1 proceeds to #58 and checks whether the signal S1 is output, that is, if the release button (not shown) is pressed ttS1.
FlI check whether there is a bug that has been pressed down to the stroke.
Set. Then, if the signal SI is output, the microcomputer 2 returns to #50, and if the signal SI is not output, the microcomputer 2 returns to #10. Therefore, in the camera of this embodiment, it is necessary to press and hold the release button (not shown) up to the PJ1 stroke.
As a result, 7 orcus lock and AE lock are established. When detecting in #56 that the signal S2 is being output and proceeding to #60, the microcomputer 1 first performs focus adjustment. That is, the microcomputer 1 outputs a signal to the lens driving means 14 to advance the lens to the lens stop point determined in #38. Subsequently, the microcomputer 1 determines the time LcB until the shutter is closed and the time td until the flash is emitted, based on the control data of the shutter and the flasher obtained in #40 (#62). Note that when shooting with natural light, do not set the time Ld, and reset and start the built-in timer (
At the same time, a shunter opening signal is output to the shutter driving means 15 to start the shutter opening operation (#66). After starting the shutter opening operation, the microphone
In case 1, the timer time (measured value of exposure time) t is the above time tcl:a! PL-Check whether it is good or not (#70). If L=tc, the microcomputer 1 controls the shutter driver r,
A shutter closing signal is output to Q15 to start the shutter closing operation (#72), and the process proceeds to #74. If ≠ [C, skip to #74. In #74, the microcomputer 1 determines whether or not flash photography is being used, and if it is 7-ray photography, the process proceeds to #75, and if natural light photography is being performed, it skips to #78. In #75, the microcomputer 1 checks whether the time measured by the timer is equal to the above-mentioned time Ld. If t=td, the microcomputer 1 sends the flash device 16 hetri signal Sx
Output and perform 7 lassie light emission ($76), #7
Proceed to step 8. If t≠td in #75, skip to #78. In #78, the microcomputer 1 determines whether or not the closing of the shutter is completed. This determination is made by detecting whether the time t counted by the timer has counted 2 tc16 (α is a predetermined value). Alternatively, a switch may be provided that is turned on when closing of the shutter is completed, and the state of this switch may be detected. As a result of this determination, if the opening of the shunter has not been completed, the process returns to #70, and if the closing of the shutter has been completed, the process proceeds to #80. In addition, in #70 and #75, the microcomputer 1
As mentioned above, it is determined whether L = tc or t = td, but strictly speaking, the microcomputer 1 first determines whether t≧L
When e, t≧td, t=te, t=Ld? W is fixed. Therefore, after the microcomputer 1 outputs the shutter close signal and the bird outputs the signal Sx, the shutter rF! The signal S× is not output. Moreover, strictly speaking, the microcomputer 1 has t>
When the time t such that tc, L>Ld has elapsed, the shutter closing signal and the bird may output the signal Sx. However, since the processing speed of the microcomputer 1 is sufficiently fast and the accuracy of the timer is sufficiently high, the error in the above determination can be ignored. When shutter closing is completed and the process goes to #80, microcomputer 1
outputs a signal to the lens driving means 14 to retract the lens to the initial position. Then, the microcomputer 1 outputs a signal to the film winding means 20 to wind one frame of film (#85). Then, the winding of one frame of film is completed, or a predetermined time from the start of winding (this is a slightly longer time than the time required to complete eight windings of one frame of film, for example 3 seconds)
(This means that the film is stretched at the last frame, and the signal Srs is output from the rewind signal output means 9.
), the process returns to #10. The above is the overall control of the camera of this embodiment. According to this embodiment, while the release button (not shown) is pressed down to the fpJ2 stroke and held, shooting is performed continuously, but after #85 there is a step of determining whether the signal S1 is output. It may be changed so that the process returns to #10 only when the signal S is no longer output.Also, a means for switching between continuous shooting and single shooting may be provided, and during continuous shooting, the switch is unconditionally changed from #85 to #10. In the case of single shooting, the process may return to #10 only after No. 13 S1 is no longer output. In this case, it may be possible to always focus on natural light photography when taking quick pictures. In addition, with the camera of this example, 7 laser shots! @When shooting in the shadow, the release was locked if the main capacitor was not fully charged, but I changed it to proceed to #53h-etc. #56, and when shooting with the flash, the main capacitor was not fully charged. It may also be possible to make it possible to perform a photographing operation even when the camera is in use. Note that even with this modification, in the camera of this embodiment,
As mentioned above, when the main switch (not shown) is ON, the main capacitor is always being charged, so the probability of improper exposure is extremely small. [Photometry/Distance Measurement 1 <Photometry> FIG. 3 is a diagram showing the photometry area of the photometry means 13. As shown in the figure, there are three spot photometry areas, C and R, approximately in the center of the photographic screen FRM, and surrounding them is a peripheral photometry area OUT. These four areas, C, R,
The photometry 11 area LMA is set by OUT'T, and the light receiving means shown in the figure below, which is included in the photometry means 13, has respective areas C and R. 0 [J Receive the light incident on T individually. and,
After the brightness of the incident light is converted into an electrical quantity by each light receiving means, it is logarithmically compressed, and A PEX (a B
It is output to the microcomputer 1 as V. Note that the specific circuit configuration of the photometric means is already well known, so a description thereof will be omitted. Furthermore, as is clear from the figure, the light from the main subject S mainly enters the photometry area LIC1R, and the light from the main subject S enters the photometry area LIC1R.
Light from the background is mainly incident on the UT. Note that in this embodiment, there is only one photometric area into which light from the background mainly enters, but the peripheral photometric area OUT may be divided into a plurality of areas. In addition, there are three photometering sources where light from the main subject S enters, but there may be two, four or more. <Distance Measurement> FIG. 4 is a diagram showing the distance measurement area of the distance measurement means 12.
As shown in the figure, five ranging areas Z1 to Z are lined up in a horizontal line approximately at the center of the photographic screen FRM. The distance measuring means 12 measures the photographing distances of objects within these five distance measuring areas using a well-known active method. Then, the distance measuring means 12 determines that the shooting distance determined by fil is the first
It detects which of the distance zones shown in the table applies, and outputs the zone number to the microcomputer 1 as distance measurement data Z. Note that the specific configuration of the distance measuring means 12 is shown in W Kono Sho 63-20338 filed by Junto Motode, so the explanation will be omitted. Of course, it is also possible to use active distance measuring means, which is already well known. <Control> Figure i@5 is a flowchart showing a specific example of step 3 (idF38) of the flowchart shown in Figure i'lS1.
, outputs +I! for photometry operation. +Start (#110)
. The microcomputer 1 controls each photometry area C. R, OUT +,: i; photometric data B Vll
Read B VC, B Vr+p+vouL (#1
20-$150). Then, the microcomputer 1 sends a control signal CT to the distance measuring means 12.
RL, is output, the shooting distance of the subject within the distance measurement area Z, is measured, and the distance measurement data Z1 is read (#2
10). Thereafter, similarly, the microcomputer 1 selects the distance measurement area z
2. Ranging day 9 at z ,, z t + z s
Z: +Z3+Zt+Zs total 3+Zt+Zswo #22
0-#250). ”: is a specific example of #36. After that, the microcomputer 1 selects among the distance measurement data Z1 to Z5.
most! If the I shadow distance is short, that is, the one with the largest zone number among ZI to Z is detected, and the zone number is stored in the register Zs (indicating the lens stop point) (#38). Therefore, in this embodiment, the focus adjustment is performed for the subject having the shortest (closest) shooting distance. By the way, each ranging area 2. -2. The distance measurement data Z, ~Z, include measurement errors. In the camera of this embodiment, the center distance measurement area 2. The distance measuring means 12 is adjusted based on the distance measuring area Z.
+ −Z 2 , Z 1. The output of Z, has a maximum error of about 2 in distance zone number with respect to the output of distance measurement area Z,. For example, when measuring the same subject (subject with the same shooting distance), each measurement ff+7 area 7Z,
The output of ~Z may be Z,=12 Z2=11 Z,=10 Z,=11 Z,=12. In other words, each ranging area 7,
, -Z If the output of S is, for example, Z,=6 Z2=5 z3=5 Z,=4 Z,=4, then the true shooting distance is Z1=4 Z2=4 Z,=5 Z, There is also a possibility that =3 Z, =2. Therefore, in the turtle horse of this example,
When the difference between each distance measurement data is small, the center distance measurement area Z
The output of , is used preferentially. Specifically, distance measurement area ZIIZ2. Z4. If the difference between the distance measurement data of Z and the distance measurement data of the central area Z is within 2,
Instead of using the distance measurement data of the area that indicates the closest distance (in this example, Z) as the lens stop point, set the distance measurement data of the area that indicates the closest distance (Z in this example) to the center point
The distance measurement data No. 3 is taken as the lens stop point. As a result, the distance measurement error M5'' can be reduced. [Exposure calculation] Next, a specific example of step #40 (exposure calculation) in Fig. 2 will be explained. <Summary> Fig. 6 shows the exposure calculation This is a chart 70 showing the outline of the routine. When proceeding to this routine, the microcomputer 11 first performs initial settings such as flags (#toooo). Next, the microcomputer 1 inputs the photometric data obtained in #36 ( Bvou
t, etc.) to determine the backlight detection level δ (#10
50). Next, the microcomputer 1 calculates the shooting distance from the AF data (lens stop point) Zs, and stores the APEX value in the register Dv (#1100).Then, the microcomputer 1 determines the range of the proximity zone (described later) (#1100). $1.15
0). Then, the microcomputer 1 receives the distance measurement data z, z2 .
z,,z1. Based on Z and AF data Zs, select the photometric data for determining the center photometric value AEc from the photometric data B vl, B vcIB vr #
1200), calculate the center photometric value AEc (#125
0). After that, the microcomputer 1 calculates the main subject photometric value BVS (#13oo). Then, the microcomputer 1 determines the shutter control value Ev-control, determines tq as to whether or not to use 7 lashes, and sets the flag Fr1 (#140o).
is 'F' I constant L (#15
00), natural light Ill El/ returns to the main program (Fig. 2), and flash photography returns $
Proceed to 1600. In #1000, the microcomputer 1 determines the 7 lash correction amount ΔEvrI, and then determines the aperture value Avcl that indicates the timing of flash emission (#1
650). The microcomputer 1 then determines whether it is necessary to perform repeated calculations (#1700). If it is necessary to perform repeated calculations, the process proceeds to #1600; if it is not necessary to perform repeated calculations, the main program (fP
Figure J2) Return. <Description of each step> Next, each step of the 70-chart shown in diagram r56 will be described in detail. "Initial Settings" This Stain 1, Microcomputer 1
In addition to resetting the FT (described in fU), the maximum aperture value (aperture value corresponding to the minimum aperture diameter) Avmα×, the maximum aperture value Av6, the maximum value E vIIlnx and the minimum value of the shutter movement range are reset. Value Evmin
, camera shake limit value U:', vb, predetermined brightness value) I
L,,HL 2(1-IL, > )(1,,2
, described later), shift amount e (described later), and upper limit number of shifts M (described later). Note that these values (shift upper limit times It
(excluding LM) are A P ITh unless otherwise specified.
It is expressed as an X value. These values differ depending on the focal length of the photographic lens. For example, when shooting at a long focal length, the camera shake limit value EVI+ becomes larger than when shooting at a short focal length (i-point distance).
o changes, and the maximum aperture value A vUAax changes accordingly.
, maximum value Ev+ain, minimum value E of shutter action range
vmax also changes. Therefore, the microcomputer 1 sets these values according to the focal length of the photographic lens. As mentioned earlier, when a teleconverter is attached, the focal length of the photographic lens is always set to the long focal length side, and the maximum aperture value of the photographic lens does not change even if the teleconverter is attached. , the above-mentioned values are set to the same values as in the case of long focal distance photography. In addition, when the signal 511fI is not output and flash emission is not prohibited, the shutter continuous r5Js
! The minimum value Evwin of the m radius is the camera shake limit value Ev
5 for h! ! Can be replaced. Therefore, in the case of a 7-meter shadow, no camera shake occurs. "Determination of Backlight Detection Level δ" As will be described later, the camera of this embodiment compares the difference between the peripheral photometric value AELI and the center photometric value ΔEc with the backlight detection level δ, and thereby detects the backlight detection level δ. Determining whether there is. Detecting backlight conditions in this way has been done for a long time, but with conventional cameras,
Since the backlight detection level δ was fixed, the following problems occurred. In an external photometry type camera that does not use light transmitted through a photographic lens, such as the camera of this embodiment, the photometry area is constant regardless of the focal length of the lens. Therefore,
When the shooting magnification rp is constant, 1, that is, when the size of the subject S occupying the shooting screen FRM is constant, when the focal length of the lens changes, the photometry area L M A for the shooting range
will change. This will be explained in more detail with reference to Figure tjS7. In addition, in the same figure, (a) is the forefoot point pressure wL (
Standard) when shooting, (1)) when shooting at long focal length (telephoto),
(e) shows when the teleconverter is attached, and the photographing magnification is the same in each case. Also, (d), (
e) and (f) show cases where the shooting distances are different during telephoto shooting, and the force in (e) is greater than that in (d).
) indicates a state where the w1 chromatic distance is shorter than that of (r). As is clear from FIGS. 7(a) to 7(c), the photometric head-mounted LMA when photographing a parrot is narrower than when photographing a telephoto photograph. Therefore, during standard shooting, the proportion of the main subject S in the peripheral photometry m area OLJ T becomes larger than during telephoto shooting, and the difference between the peripheral photometry value AEa and the center photometry value AEc is smaller than that during telephoto shooting. (The force during 7-tei shooting becomes smaller. Also, the photometric head-mounted LMA when a teleconverter is attached becomes wider than when taking telephoto WIL shadows. Therefore, when a teleconverter is attached, compared to when taking telephoto shots, The proportion of the main subject S in the peripheral photometry area OUT becomes smaller,
The difference between the peripheral photometric value AEa and the center photometric value AEe becomes larger when the teleconverter is attached than when the telephoto shooting is performed. Moreover, as is clear from FIGS. 7(d) to (f), even in the same V & shadow state (telephoto shooting state, standard shooting state, or when a teleconverter is attached), the distance IW of the main subject S (
When the shooting distance (shooting distance) becomes longer, the main subject S falls within the photometry area LMA.
C,
The proportion of the main subject S in R becomes small. Therefore, the center photometric value AEc is affected by the background brightness, and the peripheral photometric value AEa and the center photometric value AEc
The difference between them becomes smaller. Also, the entire central photometry area C, R is covered by the main subject; that area L, C, l'? Even when no light from the background is incident, the crosstalk between each photometric element increases, and the photometric values Bvl, BVC, and Bvr at C and R are affected by the background brightness. Sometimes it happens. this? ri! 11 The influence of crosstalk between optical elements is due to the background peripheral area δ11I optical region O
It becomes large when there is a light source such as the sun in the UT and the background brightness is high. In view of the above, it is desirable that the value of the backlight detection level δ changes depending on the focal length of the lens (photographing state), the distance to the main subject, and the peripheral brightness. Therefore, in the camera of this embodiment, the backlight detection level δ is given by the function δ = δ (focal length, shooting distance, background brightness) of the lens focal length, main subject distance (shooting distance), and background brightness. 3. In the camera of this embodiment, the peripheral photometric value AEn is the peripheral photometric value B volume
l: Equal, but when the peripheral photometry area OUT is divided into multiple parts, the average value of the peripheral photometry value Bvout of PJ, rlt, the intermediate value between the maximum value (brightest value) and minimum value (darkest value) Alternatively, the average value excluding the maximum value and the minimum value may be used as the peripheral photometric value AEa. Next, a specific example of the backlight detection level δ will be explained with reference to FIG. FIG. 8 is a graph showing the relationship between the background brightness Bvout and the backlight detection level δ, where A indicates the reference value, B, C,
D indicates a value obtained by correcting the backlight detection level δ in consideration of the focal length of the lens and the main subject distance. As is clear from the figure, the base value of the backlight detection level δ is the background brightness B
When vout is Bv5, δ=1.5Ev, and when background brightness BvouL is BvlO, δ"1.25Ev. In this example, the telephoto shooting state is used, and the main subject distance is When it is greater than or equal to 111 and less than 2 +e, the reference value is taken. Also, as is clear from the figure, in the camera of this embodiment, the greater the background luminance l3vout, the lower the backlight detection level δ.
is made smaller. This makes it possible to reliably detect backlight even if there is a light source such as the sun in the background and the influence of crosstalk becomes large. In other words? As the 1' base luminance BvouL increases, the influence of crosstalk increases, and as a result, the difference between the peripheral photometric value AEa and the central photometric value AEc becomes smaller.
Unless the backlight detection level δ is changed, it will be impossible to accurately detect backlight on the high-brightness side. However, if the backlight detection level δ is made small on the high brightness side as in this embodiment, backlight detection can be performed accurately even if the influence of crosstalk becomes large. Next, correction of the backlight detection level δ due to a change in the focal length of the lens will be explained. As mentioned earlier, the difference between the center photometric value AEc and the L-gog 2nd photometric value AEa is the telephoto value AEc.
Compared to standby mode, it is smaller during standard shooting and larger when a teleconverter is installed. Therefore, in order to reliably detect backlight, the backlight detection level δ may be set lower than the reference value during standard shooting, and set higher when using the teleconverter installation method 1. In the camera of this embodiment, the backlight detection level is corrected so that the reference value AI is smaller by 0.125Ev when shooting the target Qlj, and becomes larger by 0.125Ev when the teleconverter is installed. There is. Next, we will calculate the backlight detection level δ as the main subject distance changes.
We will explain the correction of If the main subject distance is extremely short (for example, less than 116),
The FyJ side photometric value AEa is lower due to the influence of the main subject (Note 2: Since we are dealing with backlight detection, the background brightness is higher than the main subject brightness. Therefore, the main subject distance When becomes shorter, the peripheral photometric value j, 1
．． The proportion of the main subject S in OtJ T increases, and the peripheral photometry value AEa decreases. However, since the central photometric value AEc corresponds to the main subject brightness, the central photometric value AEc does not change even if the main subject distance is shortened. Therefore, when the main subject distance is extremely short, the difference between the center photometric value 8Ee and the peripheral photometric value AEn becomes small. Therefore, when the main wave manuscript distance is extremely short, it is desirable to reduce the backlight detection level δ9.On the other hand, when the main subject distance is large, as mentioned earlier, the center photometry value AEc and the peripheral photometry value Since the difference from the value AEn becomes smaller, it is difficult to make the backlight detection level δ smaller as the main subject distance becomes longer. Therefore, in the camera of this embodiment, the main subject brightness is within the reference range (1

0 or more and less than 2 + o).
The backlight detection level δ is corrected to be smaller by 0.125Ev. To summarize the above, wl shape! ! ! (target, telephoto, teleconverter installed) and the combination of main subject distance,
Graph of backlight detection level δ shown in Figure 8 (A, B, C
, D) is as shown in Table 2. Note that the method of determining the amount of correction is not limited to the above-mentioned method; the absolute value may be changed between the positive correction and the negative correction, or the main subject I! The amount of correction may be changed depending on whether the separation is longer or shorter than the reference range, or the amount of correction may be determined for more detailed cases, or the background brightness B
The relationship between vout and the backlight detection level δ does not have to be linear, and the backlight detection level can be corrected arbitrarily. In addition, in a camera equipped with a TTL metering means that performs photometry using the subject light transmitted through the photographic lens, the photographing range F
The size of the photometry area LMA with respect to RM is always constant regardless of the focal length of the photographic lens. Therefore, when the TT17 method is adopted as the photometry method,
Shooting range F'l'? The size of the main subject with respect to M changes depending on the image magnification determined from the focal length of the photographic lens and the photographing distance (main subject distance). Therefore, the backlight detection level δ is given by a function of image magnification and background brightness δ=δ (image magnification, back r: brightness). Specifically, for example, the image magnification is set such that the size of the main subject and the size of the central photometric area are exactly the same, and the backlight detection level δ in this case is set to 8 as shown in Figure 8. . Then, when the image magnification is smaller than the reference image magnification, the center photometric value is more influenced by the background brightness as described in J1. ? and set the backlight detection level δ to heavy industry standard A.
(see Figure 8). Conversely, when the image magnification is larger than the reference image magnification, the proportion of the main subject in the peripheral photometry area increases, so the backlight detection level is set to C, which is smaller than 68. Of course, the image magnification can be divided into C) to determine the backlight detection level. It may be arbitrarily determined depending on the base brightness. rDetermination of object distance Dv In this person template, the microcomputer 1 calculates the distance ΔPEX4flDv to the main object. In the camera of this embodiment, this value Dv is calculated in advance and stored in the ROM. Then, microcomputer 1 outputs the AF data (
The value Dv corresponding to lens stop point) Zs is I'?
Load from OM. In addition, distance zone, AF data (
Specific examples of lens stop point) Zs and Dv values are shown in Table 111. “Determining the proximity zone range” When performing distance measurement in multiple distance measurement areas like the camera in this example, the distance measurement data for each distance measurement area is There are different things. This is because there are variations in distance measurement errors for each distance measurement area,
This is due to differences in distance measurement data due to the depth of the subject. Therefore, the camera of this embodiment compares each distance measurement data and determines t'lff whether or not it should be considered that the same subject is actually being measured even if the values are different (in this embodiment, , within the distance measurement error range, or the distance difference is 15
If the distance is within cw, it is determined that the subject is the same). In this specification, the range of distance zones that should be considered as distance measuring the same subject is defined as the proximity zone range. Next, a specific method for determining the proximity zone range in the camera of this embodiment will be explained. First, the lens stop point ZsI;! - Consider the first zone range in which the distance measurement data varies due to distance measurement errors. I of this zone range 1 soil, brick stop point Zs! I
As m, it is expressed as Zf 1 (Zs) −7,n, (Zs). However, Zr, (Zs”) is the far side limit, Zn, (Zs
) indicates the near limit, and zr, (Zs)≦Zs≦Zll(Zs). Next, consider a second zone range that includes the lens stop point Zs and in which distance measurement data varies depending on the location of the subject. As is clear from the PtS1 table, the shooting distance is short (
7 and 8 are large), the range of the distance zone becomes narrower. Therefore, the shorter the shooting distance, the greater the variation in distance measurement data. The second zone range is therefore also expressed as a function of the lens stop point Zs. That is, the second zone range is Z r 2 (Z s ) −Z n 2
(Z s ). However, Zr2 (Zs)
, Zll2 (Z9) indicate the far side limit and the near side limit, respectively, as in the first zone range, and Z r 2 (Z s )≦Z−I≦Z n 2
(Zs). In the camera of this embodiment, the union of these ff1l and the second zone range is set as the proximity zone range. That is, the proximity zone m in the camera of this embodiment is Zf (Zs) - Zn (Zs) Zr (Zs) = sin [Zll (Zs), Zr2
(Zs)]Zn(Zs) =max [Zll, (Zs
), 2112 (Z!II)]. Here is 11 inches (
a, b), wax (a+b), tsuretsure, a, b/)
Indicates the one that is not larger and the one that is not smaller. Finally, the proximity zone range of the camera of this embodiment is shown in Table 1 and in FIG. 9. In FIG. 9, the horizontal axis is the zone number indicating the main subject distance, and the vertical axis is the zone number indicating the proximity zone range. i! A line indicates the proximity zone to each brick stop point Zs. As is clear from Table 1 and FIG. 9, the shorter the main subject distance, the wider the proximity zone range. Note that in this embodiment, the adjacent zone ranges are discrete because they are represented by zone numbers. In other words, it changes discontinuously. In particular, on the long distance side, the distance range indicated by one zone number is wide, so even if the zone number shifts by just one, the adjacent zone range changes significantly. If a highly accurate distance measuring method is used, it is possible to increase the number of distance zones, so it is possible to increase the number of distance zones.
Since it is possible to more accurately determine the distance and the distance range indicated by one zone number can be narrowed, it is possible to continuously change the proximity zone range. “Central photometry value AEc candidate selection” The camera of this embodiment has three spot photometry areas L,
C and R, but their spot photometric values Bvl. Not all B vc+ 11 vr correspond to the main subject, and some spot photometric values may correspond to the background. Therefore, in the camera of this embodiment,
Using the distance measurement data, each light metering value B v
1, I3 VC, B vr correspond to the main subject or not, and the center photometric value AEc can be accurately determined. First, each distance measurement data of the five photometry areas 2. −2° and check if they are within the proximity zone range. If the distance measurement data is within the proximity zone range mentioned above, it is considered that the distance measurement data was measured for the main subject, so the spot light metering value of the spot metering area corresponding to that distance measurement area is used for the main subject. Think of it as a photometric value corresponding to . By the way, in the camera of this embodiment, as shown in Pt510 (a), the distance measurement area and the spot photometry area do not have a one-to-one correspondence, so it is necessary to consider the correspondence between them. For each distance measurement area, you can select one spot metering area that is closest to it, or select all of the spot metering areas that are close to the famous distance measurement area.
You may choose a few. In this example, fjSl('1
As shown in Figure (1)), the distance measurement area and the 11d likelihood area are made to correspond. That is, the distance measurement area Z1 is connected to the spot photometry area R, the distance measurement area Z is connected to the spot photometry area R and C, the distance measurement area Z is connected to the spot photometry area C, and the distance measurement area Z is connected to the spot photometry area C. and L
Then, distance measurement area 2. corresponds to spot photometry area L. Regarding photometry area selection, the interlocking operation of the microcomputer 1 will be explained with reference to the first figure. Figure t511 is a 70-chart showing the subroutine [selection of candidates for center photometric value AEc] in Figure 6. When proceeding to this routine, microcomputer 1 first starts with 7 lag U.
r, (Reset Jc, Ul (#2100-$21
20). These seven lags Ur, Uc, and UI are respectively set when the photometric values B Vrt B vc and B vl in the photometric regions R9C and L are adopted when calculating the center photometric value AEc. Subsequently, the microcomputer 1 determines whether the distance measurement data Z in the rightmost distance measurement area Zl is within the aforementioned proximity zone range. First, the microcomputer 1 compares the distance measurement data Z1 with the far side limit Z of the proximity zone range L(#
2200), if z<zrt', that is, if the subject within the distance measurement area Zl is farther than the main subject, proceed to @2250; if Z1≧Zf, proceed to #2210
Proceed to. In #2210, the microcomputer 1 compares the distance measurement data Z1 with the near limit Z of the proximity zone range.
2210), if ZI>711, that is, if the subject within the distance measurement area Zl is closer than the main subject, proceed to #2250; if Z,≦Zn, that is,
If the subject within distance measurement area Z is the same as the main subject, the process advances to #2220. In #2220, the microcomputer 1 performs center photometry @ A
When calculating E c, the photometric value Bvr in the photometric area R
Set the flag Or to indicate that $
Proceed to 224i0. Proceeding to #2250, the microcomputer 1 determines whether the distance measurement data Z2 is within the proximity zone range by determining tq in #225.
0. #2260), if zr≦Z2≦Z嘗1, set 7 lags U r and U c #2270. #228
0), proceed to #2300. Below, in the same way, Ue, UI
Set/reset. Incidentally, as a matter of course, the lens stop point Zs is Zr.
≦Z! Since j≦Zn is satisfied, 7 lag Ur. At least one of Ue and Ul (Saturday cent) is determined. "Determination of center photometric value ΔEc" Next, we will explain how to determine the center photometric value AEc. Two photometric areas R
, C, Ll:: Photometric data B Vr, n vc
, 13 The average value equation Ecave of vl is the central photometric value A
Ec, and when the subject is backlit, the central photometric value AEc is determined according to the position and size of the main subject. First, a method for determining the center photometric value AEc during backlighting will be explained. FIG. 12 shows an example of the photometric values of the photometering hands 19 and 13 used in the camera of this embodiment when the camera is backlit. In the figure, the horizontal axis indicates the position of the main subject with respect to the center of the shooting screen, and the further you go to the right (left) in the figure, the further the main subject is located to the right (left). shows. I1
The first axis shows each spot photometric value corresponding to the true main subject brightness B vs, tS, which becomes brighter as it goes upwards in the figure. Note that +3 va in the figure indicates the true background brightness. As is clear from the figure, each spot photometry value has the smallest error when the main subject is at the center of each spot photometry area, and the error increases as the main subject moves away from the center of the spot photometry area1, for example: When the center position of the main subject is on the left side Xo of the center of the shooting range,
Uc=UI=1. When Ur=o, the spot photometric values corresponding to the main subject are Bvc (point A) and Bvl (point B). As is clear from the figure, the error in the photometric value Bvl in the spot photometric area L (B vl - B vso) is the error in the photometric value Bvc in the spot photometric area C (
B vc-I3 v! j,). Even bigger. Therefore, in the case of backlighting, even if there are multiple spot light metering values corresponding to the main subject, it is not appropriate to consider their average value as the main subject brightness; rather, the minimum value of the multiple spot light metering values. It is more accurate to consider jfi as the brightness of the main subject, since the influence of errors is less. However, even if it is the minimum value, an error remains, so it is necessary to further correct the error. This error varies depending on at least the main subject distance, the brightness difference between the background and the main subject, the spot metering area, etc., so consider the following error function E = E (distance, brightness difference, 1lll likely area) and select it first. Further correct the minimum value. By the way, since the photometry means 13 used in the camera of this embodiment is of an external light type, the light receiving angle is constant regardless of the focal length of the photographic lens. On the other hand, in the TTI type, which performs photometry using light transmitted through a photographic lens, the light receiving angle differs depending on the focal length of the lens. Therefore, TTL
The error when adopting this method is not a function of distance but a function of image magnification, and the error I! ! The number E is calculated by E=E (image magnification, 111 degree difference, photometry area). That is, the characteristics of the error function are slightly different between the external light method as in this embodiment and the TTL method. However, in any case, the error function E must be a function of the proportion of the main subject in the photographing range, the brightness difference between the background and the main subject, and the photometry area. On the other hand, for example, as shown in Figure PI%13, spot photometry area 1'? , C, and L, if the range occupied by the main subject is quite large, the above-mentioned error will be quite small (and correction of the photometric value is hardly necessary. Therefore,
In the camera of this embodiment, +q is used to determine whether the area occupied by the main subject relative to the spot metering area is large.
The photometric values are corrected according to the results. Specifically, in the camera of this embodiment, as follows,
Whether the main subject occupies a large area with respect to the spot photometry area is determined by tlI. First, it is determined whether most (or all) of spot photometry areas L, C, and R correspond to the main subject. This determination is made at 7 lag Ul, as will be described later. This is done by counting the set flags among Uc and Ur. Then, those spot photometric values B
The variation in vl, B Vet B vr is checked, and if the variation is small, it is determined that the range occupied by the main subject is considerably larger than the spot photometry area. This variation is determined by comparing at least two of the maximum value, minimum value, and average value of the photometric values. Next, a method for determining the center photometric value AEc in the case of front lighting will be explained. In the case of front lighting, unlike the case of backlighting, the spot metering value is not affected by background brightness etc. very much.
It is not appropriate to use a single spot photometric value because it causes errors due to the influence of the reflectance of the subject being photometered. Therefore, in the camera of this embodiment, in front light, the average value AEcave of all the sub-front photometric values B Vr, B Ve, and B vl is set as the center J (light value AEc). The center photometric value AEc in the light is not limited to the average value of all spot photometric values, but may be any value that represents a plurality of spot photometric values.For example, it may be the average of the maximum and minimum spot photometric values. value (that is, the intermediate value of the spot photometric values) may be used as the center photometric value AEc.Also, the average value excluding the maximum and minimum values may be the center photometric value A
Ec may also be used, and in this case, the influence of variations in spot photometry values can be suppressed. Furthermore, among the multiple spot photometric values, find the value that has the largest number of spot photometric values that fall within a certain range (for example, -0, 2EV-+〇, 3Ev), and use that value as the center. The partial photometric value AEc may also be used. Center photometric value AEc in the camera of this example
The method for determining the value will be explained with reference to the 70-chart shown in FIG. Microcomputer 1 first calculates the average value of spot photometry values used in front lighting at l$3100, \Ecave=
Find (Bvnawate+r3vc+nvr)/3. By the way, the three spot photometric values are, as mentioned earlier,
Based on the distance measurement data, it is determined whether each object corresponds to the main subject or not (see figure f512).
The determination result can be found by examining the states of the seven lags Ur, Uc, and Ul. Therefore, the flag is set to 1 (°
It is also possible to obtain the average value of one spot photometry by using only the spot photometry values corresponding to the distance measurement area. However, in this case only one spot metering value may be used, in which case:
Since it is easily affected by the reflectance of the subject, it is not very suitable as a central photometric value when shooting in front light. Therefore, in the camera of this embodiment, at $3100, the average value AEcave is always calculated using the three spot photometric values, regardless of the states of the flags Or, Uc, and UI. In addition, count the number of spot photometric values that correspond to the main subject, and if the number is less than a predetermined value (for example, 2) (for example, 1), calculate the average value of all spot photometric values in front light. If the value is higher than a predetermined value (for example, 2 or more), the average value (or other representative value) of only the spot photometry values corresponding to the main subject is used as the center photometry value in front light. May be used as a value. By doing so, it is possible to reduce the influence of the reflectance of the subject, and it is also possible to make the center photometry value in front light correspond more to the brightness of the main subject. When the average value AEcav6 of the spot photometric values is calculated, the microcomputer 1 calculates the three spot photometric values B Vr + B Ve
Of yBVI, the number Ns of spot photometry values corresponding to the main subject is counted, and the minimum value AEcmin among them is determined for use in backlighting. First, the microcomputer 1 assigns O to Ns in #3110. At $$3115, appropriate initial values are assigned to AEe and in. As this initial value, a preset value (for example, a large value that cannot actually occur) may be used, or an average value ΔEcave may be used. It goes without saying that this minimum value AEc
min is always the photometric data B vl,
It will be replaced by either n Ve or B vr. Subsequently, the microcomputer 1 checks in #3120 whether the flag Ur is 1, and if the 7-lag Ur is 1, the process proceeds to #3122. If the 7-lag Llr is not 1, the process advances to #3130. In #3122, the microcomputer 1 increases the value of Katunta Ns by 1. Next, go to $13125,
Spot photometry value Bv of spot photometry area R at that time
Compare r and A[:cmin. Bvr<ΔEcmi
If it is a mouth, microcomputer 1 proceeds to #3128,
Replace the value of the minimum value AEc + nil with the photometric value Bvr,
Proceed to #3130. Skip to #3125 and if r3vr≧A[Ec+ai++, skip to #3130. Thereafter, in the same manner, the counters Ns, ! & Small value ΔEcma
Set n (#3130-#3148). Next, in order to determine whether it is backlit or frontlit, microcontroller 1 issues #
At 3150, the peripheral photometric value AEa to AEc+a in
Find r, f, and △Bv. At $3160, the microcomputer 1 compares the difference ΔBV and the backlight detection level δ, and when the difference ΔBv is greater than or equal to the backlight detection level δ (ΔBy≧δ),
The microcomputer 1 determines that there is backlight and proceeds to #3170. The difference △Bv is smaller than the backlight detection level δ (ΔB v
<δ), the microcomputer 1 determines that it is in direct sunlight and #
Proceed to 3165. Next, the microcomputer 1 determines the size of the main subject relative to the spot photometry area by tq. First, in #3170, the microcomputer 1 checks whether the count value Ns is 3, and when the count value Ns is 3, that is, when all three spot photometry values correspond to the main subject, Proceed to $3175. If not, proceed to well 3178. In #3175, the microcomputer 1 calculates the difference (AEca
vc AE cmin), and if the difference is smaller than 0.5, proceed to #3180. If not, #
Proceed to 3178. Is this all C2? With the camera of this example, when there is front light, the process goes to #3165, when it is backlit and it is necessary to correct the photometric value, go to #3178, and when there is no need to correct it, go to @j
It will proceed to 1.80. It is backlit and there is no need to correct the photometric value #3
Proceeding to step 180, the microcomputer 1 sets the center photometric value AEc to the minimum value AEc++Iin, and then returns to the original 70-chart (FIG. 6). It's backlit, huh?)
When it is necessary to correct the small R value AEcmin and the process proceeds to #3178, the microcomputer 1 sets the center photometric value AEc to the minimum value A.
Decreased by 1 (Ev) from Ecmin
in-1). That is, in the camera of this embodiment, in order to simplify processing, the error function E is set to always take a constant value of 1 regardless of the distance, brightness difference, or photometry area. Of course, as described above, the correction IE may be changed depending on the shooting distance, brightness difference, and photometry area. Center photometric value A
After setting Ec, the original 70-chart (Figure 6)
Return to hell. Note that the correction amount E may be determined in detail according not only to the shooting distance, brightness difference, and photometry area, but also to multiple (three in the camera of this embodiment) spot photometry values; in this case,
Since it is not necessary to determine whether or not correction is necessary,
l$3170. Step #3175 may be omitted. In the case of front lighting, when the process advances to #3165, the microcomputer 1 sets the center photometric value AEc to the average value AEeavel: and returns it to the original 7.
0 - Return to chart (Figure 6). In addition, $3170. Even if it is determined in #3175 that correction is not necessary, correction is strictly necessary, so a smaller correction than when correction is necessary may be performed in #3180. For example, in #3180, in-0,25 may be performed to AEc=8Ec (correction [0,25Ev) smaller than @3178 (correction amount is IEv). ``Determination of the main subject photometric value Bvr,'' Next, in the camera of this embodiment, the main subject brightness Bvs
Explain how to find. Note that since the processing methods are different depending on the case of front light and back light, these cases will be explained separately. i) In front light, basically the peripheral photometric value AEa and the central photometric value AEc
Let the weighted average value of the main subject brightness BV3 be the main subject brightness BV3. That is, the main subject brightness Bvs is expressed by the following equation 8%. As mentioned earlier, when the sun is shining,
A Ec = A Ecave. As mentioned above, depending on the focal length of the photographic lens, the peripheral photometry area for the photographing range F RM i: 0 UT
and spot metering area, and the sizes of L, C, and R are different (
(See Figure 7) Therefore, it is not appropriate to uniformly determine the fixed @wage. When the photographic lens is in the standard photographing state (short focal length side), even when the peripheral photometry value is OUT, the photographing range F
The size relative to RM becomes smaller and becomes about 1/3 of the i shadow range FRM in the left and right direction. Then, the spot photometry areas L, C, and R become extremely small with respect to the photographing range FRM. therefore,
In standard photography, it is necessary to set the constant W to a value that gives greater weight to the peripheral photometric value AEa. On the other hand, when the teleconverter is installed, the 1M''i 1st metering area OUT is approximately the same size as the shooting range FRM, and the spot metering areas L, C, and R are also the same size as the shooting range FRM in the left and right direction.
/3, so it is necessary to give a certain degree of weight to the center photometric value AEc. In this way, the peripheral photometric value AEa and the central photometric value AEc
By changing the weight of , it is possible to obtain an effect similar to changing the apparent light receiving angle even in an external light type photometer as in this embodiment. This concept can be applied not only to a bifocal camera as in this embodiment but also to a zoom camera and the like. Next, let's consider exposure control at high brightness (ByI 0 or more) with reference to FIG. 15. The Pt515 diagram is a graph showing the relationship between brightness values and exposure correction values, where the horizontal axis shows the brightness values and the vertical axis shows the exposure correction values. When measuring a subject with standard reflectance with a reflected light exposure meter, the brightness value is almost Bvl O even on a clear day.
In rare cases, ByIO may be reached. On the other hand, white objects with high reflectance are
~Bvl 2. Also, q on sunny days! ! When affected by light sources such as scenery or the sun, the crest shows a value of Byl 2 or higher. By the way, as shown in FIG. 15, conventional exposure control is one that controls the brightness to an appropriate level regardless of the brightness value (
, ), and a method (b) in which a brightness value greater than a predetermined brightness value is controlled by treating it as equal to the predetermined brightness value are known. However, according to the former control, even if a high-brightness subject is shaded, the high-brightness quality is not reflected in the photograph, giving an unnatural feeling. Therefore, in order to reflect the appearance of high brightness in a photo, intentional exposure compensation was necessary (based on the experience of 11il photographers).In addition, the main subject is easily affected by light sources such as the sun. In many cases, the exposure was extremely underexposed. On the other hand, unlike the former, with the latter control, it is less susceptible to light source effects, but the following problems arise. As mentioned earlier, the standard The brightness of an object with reflectance is
Although it is very rare, ByI O may be reached, so in order to properly expose a subject having a standard reflectance, it is necessary to set the predetermined brightness value to BV10 or higher. As mentioned earlier, the white subject is Habo, Byl O
~ Bvl 2, so if the predetermined value is ByI O, it is equivalent to adding θ ~ +2 EV as the exposure compensation amount for a white subject. For example, if the brightness is B
For a white subject with vl1, overexposure is corrected by +IEv. By the way, the amount of exposure compensation for a white subject is generally
It is said that around +2Ev is appropriate. Therefore, for a white subject whose luminance is Bvl 1 as described above, the amount of correction will be insufficient. In such cases, in order to increase the amount of correction, the predetermined brightness value must be lowered, but if the predetermined value is lowered too much, exposure compensation will be applied to targets and other subjects with high reflectance, which may not be appropriate. do not have. Therefore, in the camera of this embodiment, at high brightness (Bv10 or more), the first predetermined brightness value and 12 predetermined brightness values smaller than the first predetermined brightness value are used, and the photometric value is set to the first predetermined brightness. When the value exceeds the brightness value, exposure control is performed using a second predetermined brightness value (FIG. fjS15 (C)). As a result, it is possible to add a larger exposure compensation value than before for high-brightness subjects without changing the range in which proper exposure can be obtained, and it is possible to properly expose subjects with standard reflectance while improving the appearance of high-brightness. The effect of being able to reflect the results can be obtained. In addition, in order to obtain this effect, when the photometric value exceeds a first predetermined brightness value (for example, BvlO), exposure compensation may be performed to the over side by a first predetermined value (for example, IEv) (15th Figure (d)). Furthermore, when the photometric value exceeds a second predetermined brightness value (e.g., Bvll) that is larger than the first predetermined brightness value (e.g., Bvlo), a second predetermined brightness value that is larger than the first predetermined fi (e.g., IEv) is determined. The exposure may be corrected to the over side by (for example, 2 Ev) (FIG. 15(e)). Third, the situation of the subject may be estimated based on the distance to the subject, and the amount of correction may be changed accordingly, or the amount of correction may be set to zero. The above is the method for determining the main subject photometric value Bvs in front light. 1i) In the case of i-color light, in order to avoid the influence of the background, let the center photometric values A and Ec be the main subject brightness Bvs. That is, Bvs=AEc. Next, a specific example of the method for determining the main subject brightness Bvs in the camera of this embodiment will be described with reference to the flowchart shown in FIG. First, the microcomputer 1 compares #4110t' brightness difference ΔBV (see #3150 in FIG. 14) with the backlight detection level δ, and if ΔDv≧δ, that is, backlight, the process proceeds to #4120, and if ΔI3v<δ, that is, In case of direct sunlight, proceed to I4150. In the case of front lighting, the microcomputer 1 is #4150h-C
2 #4190, the weights of AEa and AEc are determined. In the camera of this embodiment, the weight is determined by the ratio of the peripheral photometric value AEn to the central photometric value AEc, depending on the shooting condition (difference in focal length of the photographic lens) and the lens stop number, χZs, which corresponds to the distance of the main subject. , is set to one of the following. Microcomputer 1 uses Hxso+2 to check whether a teleconverter is installed, and if a teleconverter is installed (when 7 lag Ftc is set), it proceeds to #4155 and determines that it is not installed. and F& (when 7 lag Ftc is not entered), proceed to #4170. In #4155, the microcomputer 1 checks whether Zs≧2, and if ZS≧2, that is, Zi≠1, the microcomputer 1 checks #4155.
Proceed to 4160, and when Zq<2, that is, Zs=1, @
Proceed to 4190. As will be described later, when proceeding to #4190, the peripheral photometric value A
The weight of Ea is increased because the main subject is far away and it is more appropriate to consider it as part of the background. In #4160, the microcomputer 1 sets N=1 and sets the weight ratio of the peripheral photometric value AEa and the central photometric value AEe to 1:1. In other words, the shooting range FR when the teleconverter is installed
Considering the relationship between M and the photometric range LMA (see rjS7 (e)), a large weight is also given to the center photometric value AEc. After setting N, proceed to #4200. In #4170, the microcomputer 1 checks whether the focal length of the lens is on the long focal length side, and if it is on the long focal length side (if 7 lag Ftele is set), it proceeds to #4175, and if it is on the short focal length side. Otherwise (if 7 lag Ftele is not set), proceed to #4190. In #4175, microcomputer 1 checks whether Zs≧3, and Z! If 1≧3, proceed to #4180 and Z
When s<3, that is, Zs=1 or Zs=2, #
Proceed to 4190. This is because, as mentioned above, the main subject is far away, and it is more appropriate to consider it as part of the background. In 94180, the microcomputer 1 sets N=2 and sets the weight ratio of the peripheral photometric value AEa and the central photometric value AEc to 3:1. As is clear from Fig. 7 (1+) and (e), in the telephoto state, the size of the photometry range LMΔ relative to the shooting screen FRM is smaller than when the teleconverter is attached, so the weight of the peripheral photometry value AEa is It is slightly larger than when the converter is installed. After setting N, proceed to #4200. In #4190, the microcomputer 1 sets N=3 and sets the weight ratio of the peripheral photometric value AEa and the central photometric value AEc to 7:1. As mentioned earlier, in standard shooting conditions, or
Proceed to #4190 only when it is better to consider the main subject as part of the background because the main subject is far away. In the standard shooting condition, as is clear from Fig. 7(a), the photometry area LMA becomes much smaller than the shooting range FRM, and the main subject occupies most of the photometry area LMA. . Therefore, in the camera of this embodiment, in such a case, the weight of the peripheral photometric value AEa is increased. When proceeding to #4200, microcontroller 1 executes the previous step (#4200).
4160. #4180. The main subject brightness BV9 is calculated based on the weight of the peripheral photometric value AEa and the central photometric value AEe determined in the following procedure ($4190). Note that, as mentioned earlier, in the camera of this embodiment, in front light, AE c= AE ca
ve, thereby making it possible to reduce the influence of differences in the reflectance of the main wave 7y body. After finding the main subject brightness l3vs, proceed to #4210,
The microcomputer 1 compares the main subject brightness Bvs with a high brightness first predetermined brightness value H1:, + (for example, ByIO), and when Bvs≧HL, the process proceeds to #4220 and the Bvs
When HLl is reached, the process returns to the flowchart shown in FIG. At #4220, the main subject brightness Bvs is replaced with a predetermined brightness value HL2 of 792 (for example, Bv9) smaller than the predetermined brightness value II L of f:tSl, and the process returns to the flowchart shown in FIG. That is, in this example, the correction shown in FIG. 15(c) is made 1,000 times. On the other hand, if it is backlit and the process proceeds to #4120, the microcomputer 1 substitutes the center photometric value AEc for the main subject brightness Bvs. As mentioned earlier (see Figure 14), in this case, the value of the center photometric value AEc, AEm city 1 or (AEmi
n1). Thereafter, the process returns to the 70-chart shown in FIG. FIG. 17 shows a modification in which the control at high visibility in direct sunlight is limited to the case of long distances. This is the first
Step #4215 in the part inside the line -' in Figure 6
is added, and the pond step is omitted. In #4215, the microcomputer] is wondering if the lens stop point Zs is Zs=1? I+set, ZS=1
When , proceed to l$4220 and Zs≠1, that is, Zs≧
2, the process returns to the 70-chart shown in FIG. 6. In other words, in this modification, the main subject brightness BvB is corrected only in the case of front lighting, high brightness, and long distance. Note that the reason why the distance is limited is that high brightness control is performed only in cases such as snowy scenes. "Determining the shutter control value Ev-control and determining the use of the flash" Next, step @14 of the 70-chart shown in FIG.
An example of the costume of 00 will be explained with reference to FIG. First, the microcomputer 1 turns on the light emission prohibition switch (not shown).
It is determined whether or not (#5100). Based on the alarm stored in #32 of FIG. 2, when it is determined that the flash prohibition switch is ON, the microcomputer 1 outputs $1.
Proceed to 5110, otherwise proceed to #5120, 5
In siio, microcomputer 1 is EV-control
= B vs 10S v Perform the operation and proceed to #5300. When the process advances to $5120, the microcomputer 1 determines whether it is backlit or frontlit. Detecting backlight and getting 1st! When photographing distant scenery with a camera that fires a flash, the flash almost never reaches the subject, so even if you fire the flash,
It makes no sense at all. Therefore, in the camera of this embodiment, #5
120, the microcomputer 1 determines whether the main subject is far away or not (#5130). (#5150)
. 7 lag Ffl showing flash emission in #5150
After setting (backlight automatic light emission), the microcomputer 1 sets the peripheral photometry value AEa and the predetermined brightness value HL of high brightness Pt5l.
, (for example, F3V10), and AEa<+IL
If +, go to #5170, AEa≧HL. If so, proceed to @5180. In #5170, the microcomputer 1 sets the shutter control value Ev-control to I(AEa-1)+Svl so that the background is over IEV in order to express the appearance of backlighting.
Assign the value of and proceed to #5250. Note that the amount by which the background is exceeded does not necessarily have to be IF, v, and may be a constant value. When proceeding to jt5180, the peripheral photometry value AEa
If the brightness value is greater than or equal to the predetermined brightness value HL, it is possible that the background is quite bright or that there is a light source in the background. Therefore, in the camera of this embodiment, the shutter control value Ev-control is set to a predetermined value! −r L , the sum of the smaller predetermined brightness value HL2 of m2 and the film sensitivity Sv is substituted, and the process proceeds to #5250. That is, E v-c
ontrol=HL 2+ S v. As a result, it is possible to more clearly express the degree of 1lffil'l1 degree r>L of the background when backlit, and it is also possible to reduce the influence of the background light source. In addition, 951801: #Ite, #5170's! - The amount of overlapping of the background may be larger than the amount of overlapping of the background (IEv). For example, Ev-control::(8Ea
-2) The value of +Sv may be substituted. Front light in #5120? When l + constant (△Bv〈
δ), or when the main subject is far away in #5130? When η is set (7, S= 1), the microcomputer 11
, t # 5140 D, and it is determined whether or not forced light emission is occurring. As a result of backlight detection, the process proceeds to @5140 only when the flash is not to be emitted, but in the camera of this embodiment, the photographer wanted to perform 7L:L photography and turned on the forced flash switch (not shown). At times, I try to respect the photographer's intentions and use flash photography. Therefore,
When the microcomputer 1 detects in #5140 that the forced flash switch is ON based on the information stored in #32 in FIG.
Sen the lag Ffl) Proceed to L (#5190), #52002. Also, in #5140, the forced flash switch is set to ('I
When it is detected that it is FF, it skips to l$5200. In #5200, the microcomputer 1 calculates Ev-control=Bvs+Sv as in #5110, and proceeds to #5250. In #5250, the microcomputer 1 sets the shutter control value Ev
-control and the exposure value Evl+ corresponding to the camera shake limit (before switching to low-luminance light emission), and
If trol≦Evb, proceed to #526o and Ev-c
ontrol > Ev! In #5260, the microcomputer 1 sets the 7-lag FN to fire the flash and automatically fires the low-brightness signal.
), then proceeds to #53 ('10).Next, the microcomputer 1 calculates the obtained shutter control value Ev-c.
It is determined whether or not ontrol is within the shutter interlocking range (#5300 to #5330). First, the microcomputer 1 calculates the obtained shutter control value Ev-contr.
Compare ol and the maximum shutter control value EvII+ax #5309), E v-control > E
If vmax, shutter control value Ev-contr
Reset ol to maximum value Ev+aax (#5310)
. Also, is the shutter control value Ev-control and the minimum value Evmin of the shutter control value compared? ff1L
(#5320), E v-control<Evmin
If so, the shutter control value Ev-control is reset to the minimum value Evmin (#5330). After setting the shutter control value Ev-conLrol and the 7-lag Ffl in this way, the process returns to the flowchart shown in FIG. fpJ6. Note that, according to this 70-chart, when forced light emission is performed, the main subject may be overexposed. Therefore,
Steps #5140 to #5200 may be changed as shown in FIG. 19, and the main subject may be exposed as appropriately as possible, as described below. First, the microcomputer 1 determines in #5140 whether or not it is forced light emission, and if it is not forced light emission, as described above,
If it is 0 forced flash, which calculates E v-control = B v * + S v, after setting 7 lag Frl (#5190), microcomputer 1 determines tq whether the main subject is far away ( #5195). As a result of the determination, if the main subject is far away (Zri = 1), the microcomputer 1 proceeds to #5200 and sets the shutter control value Ev-co.
Set ntrol. On the other hand, if the main subject is close to some extent (Zs≧2), the microcomputer 1
Trol = B vS + 1 + S v is calculated to find the shutter control value 1": y-Control. In this way, in the case of forced flash, if the main subject is close to a certain extent, the exposure of the main subject due to constant light can be adjusted. Since it is controlled so that only IEv is under, this shortfall is reduced to 7.
By supplementing with Lancille light, you can properly expose the main subject. However, in this case, the background is underexposed by Icy. In addition, when the main subject is far away, the shutter control value is set so that the main subject can be properly photographed using only constant light, but even if the flash is used, the main subject will still be 7.
Since the flash light does not reach the main subject, it will not be overexposed. 7. Determining the amount of LASOCHU correction ΔEvil In conventional flash m shadows, natural light components are ignored and proper exposure can be achieved only with flash light. Therefore,
When the natural light component cannot be ignored, the subject is overexposed, especially in daytime synchronized w1 shadows. Furthermore, there is also a camera that changes the flash emission timing only in the case of daytime synchronized photography, and controls the exposure using 7-laser light so that it is under-exposure by a predetermined amount with respect to the appropriate exposure value. However, depending on the situation of the subject, it may not be possible to provide appropriate exposure just by under-exposure by a predetermined amount. Furthermore, even in the case of 7-lash photography at low brightness, the natural light component may not be negligible. Therefore, in the camera of this embodiment, the natural light (stationary light) component of the main subject is always taken into consideration during 7-speed shooting, regardless of the low f'l1 degree or backlight, and the amount of light that is insufficient with the natural light component alone is taken into account. The flash light emission is controlled so that it is supplemented with 7 lashes of light. As a result, the main subject is always properly exposed. When the shutter control value is E v-control, the main subject brightness is Bvs, and the film sensitivity used is Sv, when exposed with only natural light, the difference ΔBVS between the main subject's exposure value and the appropriate exposure value is Δ13 vs = BV! 3- (E v-contr
ol - S v). For example, l5O100
(Sv=5) using a film, B v-;=2
, 5, if E v-control = 8.5, Δ
Bvs=-1, and if exposed using only natural light, the main subject will be underexposed by IEv. By the way, if you multiply the amount of light necessary to properly expose the main subject by 11, the amount of light provided by adding 1 natural light (i.e., the ratio of natural light to proper light ↑) is ABv9
becomes. For example, when the main subject is properly exposed with only natural light (ie, ΔBVS20), the natural light will be 1. Also, if you expose the main subject only with natural light, it will be underexposed by IEv (i.e. ΔBvs = -1)
, natural light will be reduced to 1/2. Furthermore, if you expose the main subject using only natural light, it will be underexposed by 2Ev (△
Bvs=-2), natural light becomes 1/4. When there is no natural light, ΔBvs=−■. therefore,
The amount of light that is insufficient with natural light alone, that is, the amount of light that should be compensated for by ΔBvs for flash light, is 1-2.When the main subject is made appropriate with only 7 rancius likelihood (when the 7 rancille likelihood is 1), The main subject cannot be properly exposed unless the amount of flash light is reduced. If the correction amount of this flash light intensity is expressed as ΔEv'I in APEX value, then ΔBvs ΔE vN= log2(1-2).For example, if there is no natural light at all (ΔBvs=
-cl)), ΔEvfl=0, and the main subject will not be properly exposed unless seven flashes of light are emitted so that the main subject will be properly exposed with just the flash light. Also, if the main subject is underexposed by IEv with natural light only (ΔBvr, = -1), ΔEvfl = -1, and if the main subject is underexposed by IEv with flash light only, then the main subject will be underexposed by IEv. , properly exposed with natural light and 7 rays. Furthermore, with only natural light, only 2Ev will be 7 ng 1
s = -2), △Evf1 = -0,42, and if the main subject is under-lit by about 0.42 Ev with flash light alone, the 7-ray beam is fired, and the soil subject is 7-rays lower than the natural light.゛Proper exposure with light. When the main subject is properly exposed using only natural light (ΔB
vs=0), ΔEvfI=-■, and it can be seen that in order to properly expose the main subject, the 7-ranci effect is -off and unnecessary. The difference ΔBvs between the exposure value of the main subject on the island and the appropriate exposure value when exposed only with natural light, and the flash correction amount ΔEν
Figure 20 (a) shows the relationship between the difference ΔBvs and the 7 Lassie light intensity (ratio of the flash scene to the appropriate light intensity). The horizontal axis shows the difference Δrlvs, the vertical axis in FIG. As shown, the greater the amount of underexposure (-ΔBvs) with natural light alone (the smaller ΔBvs is), the smaller the absolute value of the 7-ramp-corrected scene ΔEvrl, and the more flash light 1. Conversely, the above difference ΔBvs The smaller the absolute value 1△Bvsl, the smaller the flash correction amount Δ
The absolute value 1ΔEvrII of Ev41 increases, and the amount of flash light decreases. By the way, as is clear from both figures, when the absolute value 1ΔBvsl of the difference ΔBvs is small (for example, −〇,
5≦Δ13vs<O), the flash correction amount ΔEvN changes rapidly, but the flash scene does not change much. Furthermore, if the absolute value of the flash correction amount ΔEvN is too large, the effect of flash light will not be reflected in the photograph. Therefore, in the camera of this embodiment, a lower limit is set for the correction amount ΔEvN so that a predetermined amount of flash light is applied even when the amount of flash light to be compensated for is very small (see Figure 21). In the camera of this embodiment, the lower limit of the correction amount ΔEvfl is set to 2Ev. When the lower limit of the correction amount ΔEvf1 is set in this manner, it is also necessary to obtain the correction amount ΔEvrl by approximate calculation, and the algorithm for calculating the correction amount ΔEvrl becomes simple. In addition, in FIG. 21, (a) shows the difference ΔBv-s and the correction amount Δ
(1>) indicates the relationship between the difference ΔBvs and the 7-lash light amount. By the way, as mentioned earlier, the camera of this embodiment has an automatic flash mode that automatically fires a 7-ray flash according to the brightness of the subject, and a flash that fires regardless of the brightness of the subject. It also has a forced light emission mode. In the forced flash mode, that is, when the photographer turns on a forced flash switch (not shown), the photographer intentionally uses the flash and wants to reflect the effect of the seven-shot flash on the photograph. In such a case, it is undesirable to make a correction, especially a large correction, that reduces the effect of the 7-run shot, as it goes against the photographer's intention. Therefore, in the camera of this embodiment, the lower limit of the flash correction amount ΔEvrI is set larger in the forced flash mode than in the automatic flash mode. Specifically, in the camera of this embodiment, the lower limit of the correction amount ΔEvrl is set to -IEv, as shown in FIG. 22(a). Moreover, as is clear from FIG.
It accounts for at least 1/2 of the appropriate amount of light. Also, tj
As is clear from Figures S21 and 22, when the main subject is bright to a certain extent (when the absolute value of 2': △13Vs is small), the forced flash mode is more effective at 7 lannon than the 0 flash 11 flash mode. Note that if a lower limit is set for the correction amount ΔEvf!, the main subject will be overexposed, but as mentioned earlier, in the camera of this embodiment, the background will be overexposed by a predetermined amount when backlit. Since the exposure is controlled according to the amount of light, the main subject will not be overexposed even when the background is backlit.As mentioned earlier, the correction amount ΔEvN is a very complex combination of logarithms and exponents. However, in an actual camera, the photometry data from the 11111 correction means 13 contains errors, and when taking into account shutter control accuracy and flash light intensity errors, it is difficult to accurately determine the correction amount ΔEvrI. Therefore, in the camera of this embodiment, the
As shown by the broken line in FIG. 22, the correction amount ΔEVr1 is adjusted near zero using a step-like function. In addition, in the camera of this embodiment, in order to prevent the main subject from being underexposed due to excessive correction of the flash light intensity, the correction amount does not become larger than the accurate value (1111 correct amount ΔEvf
The correction amount ΔEv "l is adjusted so that the absolute value of l becomes smaller). Therefore, with the camera of this embodiment, the main subject may be overexposed, but the latitude of the film is Considering that the over side is wider than the side, it is not too inconvenient even if the main subject is slightly overexposed.Next, the specifics of the correction amount △Evfl in the camera of this embodiment The calculation method will be explained with reference to FIG. 523.The 70-chart shown in FIG.
[Determination of flash correction amount ΔEvfl]). Proceeding to this subroutine, the microcomputer 1 first calculates the aforementioned exposure value difference ΔBvs (#5500). Subsequently, the microcomputer 1 determines whether the forced light emission mode is in effect (#5510). fjS2 Figure #3 Based on the information stored in Figure 32, the forced light switch (not shown) is turned on.
When detecting that it is N, microcomputer 1 outputs $5530.
Then, the correction amount ΔEvrI is determined based on the galley 7 shown in bold line in FIG. 22(a). On the other hand, if the forced light emission switch is OFF, the microcomputer 1 proceeds to #5520 t' and calculates the correction amount ΔEvN based on the graph shown by the thick line in FIG. 21(a). After determining the correction value ΔEvfl, the microcomputer 1 returns to the chart 70 shown in FIG. "Determination of aperture value Avd indicating 7-laser light emission timing" Next, control of the flash in the camera of this embodiment will be explained. As mentioned earlier, the camera of this embodiment uses a so-called lens shutter in which the shutter blades are also used as aperture blades, and when the shutter aperture reaches an appropriate size while the shunter blades are opening. Lights up 7 rays of light. 7. Set xtfft to Tv + film sensitivity to Sv, shoot the main subject! ! Let Dv be the APEX value at 5 distances.As is well known, if the aperture aperture is Avdo=Iv+5v-Dv, the main subject will be properly exposed only by flash light. In a conventional camera with a lens shutter, based on the aperture characteristics of the shutter, the time td from when the shutter starts opening until it reaches the opening [1 corresponding to the aperture value A vdo. is determined in advance, and when the time tdo has elapsed while the shutter is open, 7 rays of light are emitted. By the way, in the camera of this embodiment, as described above, even during flash photography, the 7-ranche light beam is corrected in consideration of the natural light component. In this case, by reducing the aperture aperture by an amount corresponding to the Mjt value of the correction amount ΔEvN and emitting 7 flashes, the main subject will be properly exposed with natural light and 7 flashes. That is, the aperture diameter is A vd = A vdo - △Ev41 = Iv + 5v
If the 7-lash light is emitted when the aperture value Avd of -Dv-ΔEvfl is reached, the main subject will be properly exposed with natural light and 7-lash light. FIG. 24 shows the shutter aperture characteristics of the camera of this example. In the figure, the horizontal axis indicates the time since the shutter starts opening, and the vertical axis indicates the shutter opening (diaphragm opening), and the aperture value increases (the aperture diameter decreases) as it goes downward. In the figure, A vdo is the aperture value that will properly expose the main subject with only flash light, and Avd is the aperture value that corrected Avdo so that the -L subject will be properly exposed with natural light and flash light. This is the latter aperture value. As is clear from the figure, the aperture aperture is at both aperture values Avdo,
The time it takes to reach Avd is tdo, respectively.
, td. In addition, in the figure, Avc is the shutter control value Ev-
control is the aperture value determined based on t
c is the time required for the aperture aperture to reach the aperture value Avc, and when time Lch' has elapsed since the shutter started opening, the microcomputer 1 outputs a signal to the shutter control circuit 15 to start the shutter opening operation. and,
As is clear from the figure, the shutter control waveform has a triangular shape. Marco and Avo are the open aperture values of the aperture, and when a very dark subject is photographed using only natural light, the shutter control waveform becomes trapezoidal, as shown by the broken line. Note that tc' is the timing at which the shutter is closed in this case. By the way, in the camera of this embodiment, as described above, the flash scene is corrected so that only the amount of light that is insufficient with natural light alone is compensated for with seven lashes of light. In such a camera, when the flash light does not sufficiently reach the main subject, such as when the main subject is far away, the main subject may be underexposed. Therefore,
In the camera of this embodiment, if there is a risk that the main subject will not be sufficiently exposed to the 7-lash light, the shutter control value Ev-co
ntrol is shifted to the overexposure side to increase the proportion of natural light. The appropriate shift amount in this case is determined by considering various conditions.
It can be determined by calculation. However, in the camera of this embodiment, in order to simplify the algorithm, the shutter control value Ev-c. The computation for flash control is repeated while shifting ntrol by a predetermined amount e. Also,
An upper limit M of the number of shifts is set so that the background etc. will not be extremely overexposed due to an excessively large shift amount. Here, let us consider the upper limit M of the number of shifts of the shutter control value Ev-control, one shift), and ie. In the case of backlight photography, the camera of this embodiment sets the shutter control value Ev-c so that the background is overexposed by IEv than the proper exposure, as described above. nLrol is set. If sufficient light does not reach the main subject, the shutter control value is shifted to the overexposure side by ne. That is, E v-c
ontrol=EV-control-ne
It is. However, 1. +1 is the number of shifts. Therefore,
The background will be overexposed by 1+ne. As long as the amount of overexposure is within the latitude of the film, there will be no problem with the photograph. For example, if it is a negative film, the latitude on the overexposure side is about +3, so the upper limit of the number of shifts should be determined so that 1+Me=3, and M=.<, e=0. 5 or M = 2
, e = 1, the upper limit M and the predetermined amount e can be determined arbitrarily, taking into account the accuracy of exposure control, calculation speed, etc. Of course, the latitude information of the film to be used can be read from the film's DX hood, Accordingly, the upper limit M1 predetermined Jlle may be changed. Next, the shutter control value Ev in the camera of this embodiment
- For a specific example of how to shift control, ff525
Please explain with reference to the diagram. First, the microcomputer 1 calculates the aforementioned aperture value Avd (#6100). Next, the microcomputer 1 determines the aperture value Avc (see diagram QT24) corresponding to the apex of the shutter waveform based on the shutter control value Ev-control (# (3110). In the camera of this embodiment, the shutter Based on the control waveform, the aperture value Ave corresponding to the shutter control value Ev-control is determined in advance, stored in the ROM, and read out from the ROM when necessary. , My Fun 1 resets 7 lag C0NT (
#6120), this 7-lag C0NT is set when it is necessary to calculate the frit values Avd and Avc again because the shutter control value Ev-control has been shifted. After resetting the 7-lag C0NT, the microcomputer 1 determines whether the 7-lag light sufficiently reaches the main subject. First, microcomputer 1 has an aperture value of $61 (Av calculated by 10).
d and the maximum aperture value of the shank (the fringe value corresponding to the minimum aperture) Avmax (#6150), and then A vd > A vmux, that is, stop down to the minimum aperture and emit 7 lashes 1. If the main subject is overexposed due to 7-ray light and natural light, #
(Proceed to step 3155 and reset the aperture value Avd to AvmaX. This is because if the setting is not reset, 7 lashes will be emitted before the shutter opens. Aperture value Avd
If the setting is reset, the screen returns to the 70-chart shown in FIG. If Avd≦A vmax in #6150, proceed to microcomputer 1 (Sat, #G1C, O) and check the aperture value Avd found in #6100 and the aperture value Avc found in #6110.
Compare with. If Avd≧Avc, then when the aperture value of the shutter aperture reaches Avd (when time Ld has elapsed since the shutter starts opening), if 7 lashes are emitted, the main subject will be exposed to natural light and the flash. Since the light is properly exposed, no correction is made and the process returns to the 70-chart shown in FIG. - If Avd<Avc in #6160,
Even if the shutter is opened to the aperture aperture determined based on the shutter control value Ev-control and the flash is fired, there will be insufficient light of 7 rams and the main subject will be underexposed. Therefore, in order to increase the ratio of natural light to the proper exposure and properly expose the main subject, the microcomputer 1 sets the shutter control value E v-co
In order to make nLrol overexposed, @G
Proceed to 170. In #6170 to #6190, the microcomputer 1 determines whether or not shifting the shutter control value Ev-control will cause no problem. In #6170, the difference ΔBvq between the exposure value of the main subject and the appropriate exposure value when exposed with only natural light is checked. Then, if Δ139S≧0, that is, when the main subject is properly exposed or overexposed by only natural light, the microcomputer 1 (Sat, shutter control value IE v-con
Without shifting the trol, proceed to #6175 and reset the aperture value Avd to the aperture value Avcl:. This results in
The degree to which the main subject is overexposed can be minimized. At $6170, if △Bvs<O, #613
0, and microcomputer 1 sets the aperture value A obtained in #6110.
Is vc equal to the open aperture value Avo? Q is determined. Then, if Avc=Avo, that is, Sha
Even if the /ter control value Ev-eonLrol is shifted further, the timing of the 7-721 flash cannot be delayed, and the amount of 4-element 7-ray nosier light on the main subject cannot be increased any further. If not, the process proceeds to #6175, where the aperture value Avd is reset to the aperture value Avcl: and subsequent shifts are canceled. This allows the main subject to be exposed as accurately as possible. 1$6180, if Avc≠Avo, the microcomputer 1 proceeds to #6190 and sets the shutter control value Ev-c.
Determine tq whether the number of shifts SHI FT of ontrol has reached the upper limit M. And the number of shifts is 5HIF
If T has reached the upper limit M, the process proceeds to #6175, where the aperture value Avd is reset to the aperture value Avc, and shifting after one step is prohibited. At $6190, the number of shifts S l-I I F
If T has not reached the upper limit M, microcomputer 1
Proceed to 00 and enter the control value E v-control
Shift l by a predetermined @(・ to the overexposure side. That is, E v-control = E v-eonLrol
-e. After shifting the shutter control value Ev-control, the microcomputer 1 shifts the shutter control value Ev-control to the shifted shutter control value Ev-control.
It is determined whether the shutter can be controlled based on -control (#6210). That is, the microcomputer 1 compares the shutter control value EV-control that has been shunted with the minimum value Evmin of the shutter control value that is to be rewritten. And Ev-c
. If ntrol < E vmin, that is, if shutter control is impossible, microcomputer 1 selects #62
Proceed to step 20 and enter the shutter control value E v-control
The minimum controllable value Ev
Reset to min and proceed to #6230. On the other hand, Ev-
If control≧Evn+in, that is, if shutter control is possible, press I6230. In #6230, the microcomputer 1 increments the counter 5HIFT indicating the number of shifts, and then @G24
0, to calculate the fringe value Avd again, 7 lag C0N
Set T. Then, return to 70-cha shown in FIG. As is clear from the above, in the camera of this embodiment, the aperture value Avc calculated based on the shutter control value Ev-ctn+j, rol reaches the maximum aperture value Avo (that is, the shutter is opened up to a maximum of 111 openings C). ) or the number of shifts SHIFT is -
Shutter control value Ev-c until reaching L, @M
Ontrol is shifted. E′! i-type example 1 Next, a modification of the camera embodying the present invention will be described. "First Modification" In the camera of the embodiment described above, the photometry area LMA of the photometry means 13 has three areas in the center, C, R, and C, as shown in FIG. The area around them O
It was divided into four parts by UT. However, as described above, the photometric area LMA is not limited to this, and various other types can be considered. Therefore, a modified example of the photometric means having a different photometric area from that shown in FIG. 3 is shown below, and the shunter control value Ev
The method for determining -cc+ntrol will be explained. FIG. 26 shows the photometric area of the photometric means of this modification. As is clear from the figure, the photometric area L M A of this modification example
is the long sword-shaped first part located in the center of the shooting screen FRM.
It is composed of a central photometric τ region P, a long sword-shaped second central photometric region Q existing around the central photometric region P, and a peripheral photometric region R located around it. The size of the first central photometric area P is determined to be approximately equal to the size of the photographing range when the focal length of the photographing lens is 200a+111. In addition, the second central photometric distribution area Q, when the first central photometric area P and the ft42 photometric distribution area Q are combined, corresponds to the size of the photographing range when the focal length of the photographic lens is 100 kasu 1a. It is set to be approximately equal. The total photometric area T,, M A is determined so that its size is approximately equal to the size of the shooting area V when the focal length of the shooting lens is 5 + 1 m + n. . A method for determining the shutter control value Ev-control in a camera equipped with a photometric means having this photometric area LMA will be described. This camera is equipped with a zoom lens that can change the j and Q point distances from 28 mm to 135+oIo, and each focal length of the photographic lens will be explained below. (+> When the focal length of the photographing lens is set to 35n+ml: In this case, as shown in Fig. 27, the photographing range FRM is
It is slightly larger than the photometric area LMA. Therefore, at this time, there are three photometric areas P and Q. By equalizing the weights of the photometric values Bνll+ r3 vc+ and By+ in R, the shutter control value [Ev-con
Find troll. That is, Ev-control=(Bvp+Bvq-!-Bvr
), '3 +Sv. (n) When the focal length of the photographic lens is set to 50 mm and 1 m In this case, as described above, the photographing range FRM is approximately equal to the photometry area LMA. Therefore, in this case, since the main subject is usually located at the center of the shooting range FRM, and in order to reduce the influence of the sky, etc., which is likely to exist in the periphery, the outermost photometry area R1: The photometric value Bvr is not adopted, and the first and second central measurement values P
, Q to find the shutter control value E y-cOnLrol by making the weights of the photometric values BVlly B vq equal, that is, E v-control= (B v
p+Bvq)/2+Sv. (III) When the focal length of the photographic lens is set to 1001 In this case, as mentioned earlier, the photographing range FRM is rjS
The size is approximately equal to the sum of the first central photometric area P and the second central photometric area Q. Therefore, in this case, since the main subject is usually located at the center of the photographing range FRM, and in order to reduce the influence of the sky, etc., which is likely to exist in the periphery, the innermost photometry area Pl: Using only the light metering value Bvl+, the shutter control value Ecc
Find ontrol. That is, Ev-control=[1vp+Sv. (IV) When the focal length of the photographic lens is set to a focal length other than the above (i) When it is less than 35° In this case, the shutter control is performed in the same way as when the focal length and α distance of the photographic lens are set to 35m + 6. value e c co
Find ntrol. That is, Ev-control
=([3vp+Bvq+Bvr)/3+Sv. (ii) In the case of 100+nm or more In this case, the shutter control value E v-co is
To find nLrol, E v-control
l=Bvp+Sv. (iii) In other cases, the focal length of the photographic lens should be set to 35 mm to 50 mm.
When setting m+fi to 100 mIfi, the photometric value B vpt B VQ at each photometering device P, Q, and H is determined according to the focal length of the photographic lens, as shown in Figure @28.
+B The shutter control value Ev-control is determined by continuously changing the weight of vr. In this modification, the weight of the photometric value B-VIl+B VQ+Bvr is changed linearly, but it goes without saying that the sum of m of each photometric value BVp+BVq+Bvr is 1. It may also be changed in a curved manner. “Second Modification” In the camera of the above-mentioned embodiment, when considering the second zone range in which the distance measurement data varies depending on the depth of the subject,
If the distance difference was within a predetermined value (specifically, 15 am), it was assumed that the same subject was being measured. By the way, when a large number of people gather together to take a commemorative photo (usually taken from a distance), the photographing distance differs depending on the person in the front row and the person in the back row. For example, when shooting in three rows, the difference in shooting distance between the person in the 11ηth row and the person in the last row is about h.
Reach i. In such a group photo, both the person in the front row and the person in the back row should be considered to be the same subject, but as in the example above, the distance difference to be considered the same subject is set constant. In this case, when taking a photo such as a group photo in which the distance range that should be considered as the same subject is large, the proximity zone range cannot be detected correctly. Therefore, the distance ffL that should be considered to be the same subject
;! It is better to make the distance difference variable than to make i constant. In addition, when photographing a subject in depth, commuting to school and photographing distance become longer, so it is desirable to increase the distance difference as the photographing distance becomes longer. Also, it can be considered to be in focus.Han 17
11 (W depth of field) considers that the far side is deeper than the near side, and defines the range that is considered to be the same subject.
It may be slightly larger so that the far side is wider than the near side. Table 3 shows a specific example of the relationship between the shooting distance and the distance difference that should be considered the same in this modification.As is clear from Table 0, in this specific example, as mentioned above,
The above-mentioned distance #l difference becomes larger as the shooting distance improves, and is larger on the long distance side than on the short distance side. Table 1 Table 2 Standard - Standard (short distance) Focal length) Shooting 38mm telephoto
...Telephoto (long focal length) photography 80+11111TC
...Equivalent to 105mm when the telefunter is installed, Table 3, 1! As explained above, in the photometric device of the present invention, the weight given to each photometric data is determined according to the information regarding the jji point distance of the photographing lens.
As the shooting angle of view changes, the apparent appearance increases and the metering range changes. Therefore, even with the external photometry method, the photometry distribution characteristics can be kept constant even if the angle of view changes, similar to the TTL method. Furthermore, if this photometric device is used to control the exposure based on the calculated weighted average value, it is possible to obtain a very appropriate exposure.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall information of a camera embodying the present invention, and FIG. 2 is a 70-chart showing the overall control of the camera. FIG. 3 is a diagram showing the photometry area of the photometry means in a camera embodying the present invention, and FIG. 4 is a diagram showing the distance measurement fπ range of the distance measurement means. Pt55 is a 70-chart showing the control of the photometry operation and distance measurement operation in a camera to which the present invention is applied. FIG. 6 is a 70-chart showing overall control of exposure calculation operations in a camera implementing the present invention. FIG. 7 is a diagram showing three photometers in each shooting state in a camera embodying the present invention, (a), (b), (
C) shows the case where the imaging magnification is constant;
The standard shooting state, telephoto shooting state, and teleconverter installed state are shown. In addition, (d), (e), and (f) show the case where the shooting distance is changed in the telephoto shooting state,
(d) shows long distance, (e) medium distance, and (f) short distance. FIG. 8 is a graph showing the relationship between the peripheral photometric value and the backlight determination level. FIG. 9 is a graph showing the relationship between the main subject distance and the proximity zone in a camera implementing the present invention. Pt5
FIG. 10 is a diagram showing the relationship between the photometry area and the distance measurement area M in a camera implementing the present invention. FIG. 11 is a 70-chart illustrating the operation of selecting candidates for central photometric photometric values in a power/vehicle embodying the present invention. Figure P512 is a diagram showing errors in photometric values in each spot photometric area when backlit in the cuff according to the present invention. FIG. 13 is a diagram showing the relationship between the photometry area and the main subject when the photographing magnification is very high in a camera embodying the present invention. FIG. 14 is a flowchart showing a method for determining a center photometric value in a camera implementing the present invention. FIG. 15 is a graph showing the relationship between subject brightness and its correction amount, where (a) and (l+) are graphs for conventional cameras, (c
), (d)l(e) show cameras implementing the present invention. f:tS Fig. 16 is a 70-chart showing a method for determining the main subject brightness in a camera implementing the present invention, and Fig. 17 is a 7a-chart showing a modification thereof. tjS18 diagram shows the method for determining the shutter control value in the camera implementing the present invention! s Yo 17 Use of Ranshu f
This is a 70-chart showing the lI constant, and FIG. 19 is a 70-chart showing a modification thereof. Figures 20 to 22 show the difference between the shutter control value and the main subject brightness, (a) the flash correction amount, and (b)
FIG. 20 is a graph showing the principle of flash light intensity relative to an appropriate scene; FIG. 21 is a graph showing the relationship during automatic flashing in a camera implementing the present invention; Similarly, the relationship during forced light emission is shown. FIG. 23 is a flowchart showing a method for determining 7 runche corrections in a camera embodying the present invention. FIG. 24 is a graph showing the aperture characteristics of the lens shutter. FIG. 25 is a 70-chart showing a method of determining the timing of flash emission. FIG. 26 is a diagram showing a modified example of the photometric area of the photometric means in a camera embodying the present invention, and FIG. 27 is a diagram showing a modified example of the photometric area of the photometric means in a camera employing the modified example of the photometric means in short focal length photography. , is a diagram showing a photometry area and a photographing range. FIG. 28 is a graph showing the relationship between the focal length of the photographing lens and the weight of the photometric value in each photometric head for determining the shutter control value in a camera employing a modified example of the photometric means. 1 ・・・・・・・・・・・・・・・・・・・・・・・・
・・・・・・・Microphone User 13 ・−・・
・・・・・・・・・・・・−・・・・・・・・・ Photometer j: 4150 to #4190 ・・・・ Weight determining means $ 4200 ・−・・−・・・・・・・・・・・・
−・・・ Arithmetic means AEc ・・・・・・・・・・・・
・・・・・・・・・・・・ Center photometry data AEa
・・・・・・・・・・・・・・・・・・・・・・・・
・Peripheral photometry data Ftc, Ftele・
...... Information regarding the focal length of the photographic lens 15, #66-78 ... Exposure control means protrusion engaged Minolta Camera Co., Ltd. Fig. 1/1 jI8 Fig. S Fig. 9 Main shock Eradication Fig. 1θ,, l ; Shaku Fig. 17 (mouth 4 zoo) Fig. 20 Fig. 21 Fig. $22 Fig. ＼ 1 ゝ, T-Z ＼ i, j Fig. 23 Fig. 24 Fig. 28, Rei S ratio %! -Kaede)

Claims (5)

[Claims] (1) A center photometer that measures the area approximately in the center of the object and outputs center photometry data, and a peripheral photometer that measures the area around the object and outputs peripheral photometry data. A multi-segment photometry device using an external photometry method, comprising: a focal length information input means for inputting information regarding the focal length of the photographic lens; A multi-segment photometry device comprising: weight determining means for determining the weight to be given to a value; and calculation means for calculating a weighted average of the photometric values of each photometric means based on the determined weight. (2) The multi-segment photometry device according to claim 1, wherein the weight determining means increases the weight of the center photometry data as the focal length of the photographing lens increases. (3) The area approximately at the center of the object field is divided into a plurality of areas, and the center photometry means includes a plurality of photometry means that respectively measure the light of the plurality of areas. The multi-segment photometry device according to claim 1 or 2. (4) The multi-segment photometry device according to claim 3, wherein the center photometry means uses a representative value of the photometry data of the plurality of photometers as the center photometry data. (5) A camera equipped with the multi-segment photometry device according to any one of claims (1) to (4), wherein exposure control means controls exposure based on the weighted average value determined by the calculation means. A camera characterized by comprising: