JPH03223821A - Camera - Google Patents

Abstract

PURPOSE:To accurately detect that a main object is in a rear light state by dividing a field into plural areas, outputting the brightness signal of every area and using the maximum value of the brightness signal and the brightness signal including a focus detecting area which is decided in accordance with selection. CONSTITUTION:The field is divided into plural small areas for photometry S01-S15 and the brightness of the small divided areas is detected by silicon diodes SPD01-SPD15 corresponding to the S01-S15. Then, the emission of flash light is decided based on comparison information obtained by comparing the brightness information of the small area including one focus detecting area selected by photodetector trains CCDL1 and CCDL2, and CCDC2, CCDR1 and CCDR2 out of the plural focus detecting areas SL, SC and SR with the maximum brightness information in plural small areas. Thus, appropriate light shielding state is discriminated even in a camera where the focus detecting area can be selected.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is equipped with a focus detection device capable of independently detecting the focus of multiple regions of a photographic field, and performs photometry by dividing the photographic field into a plurality of small regions. Regarding cameras.

[Conventional technology]

Conventionally, various photometering devices have been proposed that divide the field of view into multiple regions, output brightness signals for each region, and use these multiple brightness signals to provide proper exposure to the photographic screen. ing.

For example, Japanese Utility Model Publication No. 51-9271 proposes a photometric device that uses, as a photometric value, the arithmetic average value of the maximum value and minimum value among the outputs from a plurality of photoelectric elements.

In addition, in Japanese Patent Publication No. 63-7330, the field of view is divided into a central area and two or more areas, and a plurality of outer areas arranged to surround the central area are photometered. Photometry standardizes the brightness of each area using a reference value set between the maximum and minimum brightness values, classifies the subject based on this standardized output, and calculates the photometric value from the classified output. We are proposing a device.

In the conventional example above, little consideration was given to the placement of the main subject within the shooting screen, but this one assumes that it will be installed in a camera equipped with an automatic focus detection device, and takes great consideration to the placement of the main subject within the shooting screen. has also been proposed.

For example, in Japanese Patent Application Laid-open No. 61-279829, the center of the screen is set as the position where the main subject is placed, and the field of view is divided into a plurality of areas including at least a plurality of concentric areas centered at the center of the screen. proposed a photometric device that could accurately determine the brightness of the main subject by selectively using the brightness signals of concentric areas based on the image magnification information and assuming the size of the main subject. There is. The same bulletin also proposes changing the formula for calculating photometric values by calculating the brightness of the background in addition to the brightness of the main subject, and using these differences in brightness. In addition, if the main subject is small, it is also possible to provide an appropriate exposure for the shooting situation.

Also, in Japanese Patent Application Laid-Open No. 62-184319, the center of the screen is set as a position where the main subject is likely to be placed, and the field of view is
The difference between the brightness signals of these multiple areas and the brightness signals between adjacent areas is calculated by dividing the screen into three areas: the area at the center of the screen, the area outside it, and the area further outside it. Based on this, the publication proposes a photometer that determines the approximate size of the main subject and the shooting situation at the same time to provide the appropriate exposure.The publication also proposes a photometer that determines the approximate size of the main subject using the difference in luminance signals. Compared to estimating the size of the main subject using the photographic magnification, it is less dependent on the actual size of the main subject, making it possible to stably obtain the correct exposure. There is an advantage.

In the two conventional examples cited here, the center of the screen was assumed to be a position where the main subject would be easily placed because the focus detection area of cameras equipped with automatic focus detection devices was generally set at the center of the screen. It is. On the other hand, recent automatic focus detection devices have been proposed that have multiple focus detection areas, and in cameras equipped with such automatic focus detection devices, each of the multiple focus detection devices has a The main subject is also likely to be placed in a specific area other than the central area.

Therefore, Japanese Patent Laid-Open No. 1-202720 has been proposed as a photometric device suitable for a camera having a plurality of focus detection areas as described above. In the same publication, the brightness of the main subject is determined based on the information on the above-mentioned photographic magnification.
Applying the proposal in Publication No. 79829, in addition to the information on the photographing magnification and the focal length of the photographic lens, information on the selected focus detection area and other focus detection areas when that area is in focus Based on the information on the focus state of the photometry area and
Calculations are performed to change the weighting of the photometric area, the brightness of the main subject is accurately determined, and this is output as a photometric value for natural light photography.

Various photometric devices have been proposed that divide the field into multiple regions and calculate photometric values using various calculations, but relatively few devices have been proposed that accurately determine whether or not to fire a flash. few. As a device for detecting only a backlight condition, for example, Japanese Patent Laid-Open No. 1-280737 proposes a device that detects a backlight condition based on a luminance difference between predetermined areas.

In the above-mentioned conventional example, JP-A-1-280737, the object field is divided into a plurality of areas and only the backlight condition is detected according to the brightness difference between predetermined areas, so the focus detection point can be switched. This method is not suitable for cameras, and there is also the problem that the backlit state of the main subject cannot be accurately detected based only on the brightness difference between predetermined areas. Needless to say, since it is not possible to detect low-brightness objects at the same time in the same publication, it is desirable to have a means for detecting low-brightness objects in addition to this as a condition for flash light emission. Since this is done based only on brightness differences, there is a problem in that the situation of the subject is insufficiently recognized and backlight conditions cannot be accurately detected.

[Means for solving the problem] In a camera equipped with a focus detection means configured to be able to independently detect the focus of multiple areas within the shooting screen, the subject is divided into multiple small areas for photometry; a light receiving means for detecting the brightness of each small area, and one of the plurality of focus detection areas.
a detection area selection means for selecting one of the plurality of small areas, brightness information of the small area including the focus detection area selected by the detection area selection means, and maximum brightness information among the plurality of small areas. The present invention is characterized by a camera equipped with a light emission determining means that determines flash light emission based on comparison information, and can provide a camera that can appropriately determine a backlight state even in a camera in which a focus detection area can be selected.

〔Example〕

1 to 15 are diagrams showing a first embodiment of the present invention, and represent a camera equipped with three focus detection points.

FIG. 1 is a diagram showing the divided shape of the light-receiving surface of the photometric light-receiving section of the first embodiment of the present invention, and shows the state projected onto the field. In the same figure, SOI, S02...S15
represents a plurality of divided light receiving small areas, SL.

SC+SR represents a focus detection field of view projected onto the field of view, similar to the photometric light receiving section. In this example, as shown in Figure 1, the field of view is divided into a total of 15 small areas: 3 small areas containing 3 focus detection points and 12 surrounding small areas. The field brightness is photometered for each small area.

FIG. 2 is a diagram showing the optical arrangement of the first embodiment of the present invention,
In the figure, l is a photographing lens, 2 is a quick return mirror, 3 is a focusing plate, 4 is a penta roof prism, 5 is an imaging lens for photometry, 6 is a light receiving part for photometry, 7 is an eyepiece lens,
8 is a pupil position, 9 is a submirror 10 is a field mask, II
12 is a condensing lens, I2 is a total reflection mirror, 13 is a pupil division mask, 14 is an imaging lens for focus detection, 15 is a light receiving section for focus detection, and 16 is a film surface. In this embodiment, the subject image formed on the focusing plate 3 by the photographing lens l is imaged on the photometric light receiving section 6 by the photometric imaging lens 5, and the 15 small images shown in FIG. Photometry is performed by dividing the image into areas, and the focus of a part of the subject image formed in the vicinity of the field mask 10 placed near the planned imaging plane of the photographic lens l is detected by the focus detection imaging lens 14. Light receiving section 15
An image is formed above to perform focus detection in an area corresponding to the three focus detection fields shown in FIG. FLA indicates built-in flash device.

FIG. 3 is an exploded perspective view of the focus detection optical system shown in FIG. The subject images formed in the vicinity of these three apertures are each divided into two images by the focus detection imaging lens 14, and the images are formed on the focus detection portion 15 to focus the three points in the photographing screen. Detection is in progress.

FIG. J is a block diagram showing the circuit configuration of the first embodiment of the present invention. In the same figure, S P Do+ , S
PDO2..., SPD, 5 are the 15 light receiving small areas S o+ and S 02 shown in FIG. 1, respectively.
...+Silicon photodiode compatible with SI3 (
SPD), which generates a photocurrent according to the brightness of each small area. AMPo+.

AMPo2=-, AMP 15 and DIOI, DIO
21・”lDI +6 is an operational amplifier and a compression diode, respectively, and a silicon photodiode (SPD)
), an operational amplifier, and a compression diode constitute a light receiving means corresponding to the 15 light receiving small areas shown in FIG. FIG. 4 17 shows a photometric circuit AECKT, which A/D converts the output signals corresponding to the brightness of a plurality of light receiving small areas and outputs them as digital signals. 18
is the flash mode selection switch FLSW, and there is a forced flash mode in which the flash (built-in flash FLA) is forcibly turned on according to the operator's will, and a forced-flash mode in which the camera automatically shoots with flash according to the situation of the subject. It is possible to select either an automatic detection mode in which the flash is automatically emitted or a recommendation is made to use the flash, or a forced non-flash mode in which the flash is forcibly turned off according to the operator's will. . 15 is a focus detection light receiving section corresponding to FIG. 3, and CCDLI and CCDL.
2. CCDol, CCDo2, and CCDR.

and CCDR□ are the focus detection field of view SL in FIG. 1, respectively.

There are three pairs of light receiving element arrays corresponding to Sc and SR. The pair of light-receiving element arrays uses the optical system shown in FIGS. 2 and 3 to detect two different types of field light on the exit pupil plane of the photographic lens, out of the field light that forms an image on a predetermined area of the photographic screen. It is configured so that only the light flux that has passed through one area is extracted and formed into an image, and the amount of defocus can be detected by comparing the output signals from these pair of light receiving element arrays. 19
is the focus detection circuit AFCKT, and the focus detection light receiving section 15
Based on the output signals from the three pairs of light-receiving element arrays provided in the
The defocus amounts of the field corresponding to L+So and SR are detected, and information on the three defocus amounts is output as a digital signal. Reference numeral 20 denotes a focus detection point selection switch AFSW, which allows the camera to automatically switch according to the distribution of defocus amounts in the subject field corresponding to the three focus detection fields SL+SC+SR in FIG. 1, according to the will of the operator. An automatic selection mode in which a suitable focusing position is determined for the photographic screen, and an optional selection mode in which the operator selectively determines the focus detection field of any one of the three focus detection fields shown in FIG. Furthermore, in the optional selection mode, the focus detection point selection switch can be used to instruct the focus detection point to be selected. In Fig. 4, a photometric circuit AECKT17, a flash mode selection switch FLSW18, a focus detection circuit AF
Input signals from CKT19 and focus detection point selection switch AFSW20 are connected to an internal data bus line BUS21 of the microcomputer and used for various controls.

Further, in FIG. 4, reference numeral 22 denotes a central processing unit C that processes the various input signals mentioned above and instructs the operation of various control mechanisms using programs stored in various memories.
PU, 23 is a read-only memory ROM that stores various programs, 24 is a random access memory RAM as a work area for calculations, 25 is a display control mechanism DPCNTL, and 26 is a shutter time control mechanism 5TCN.
TL, 27 is a flash control mechanism FLCNTL, and 28 is a general-purpose input/output port P0, each of which is connected to the internal data bus line BUS21 of the microcomputer.

The CPU uses the above-mentioned input signals to execute calculations according to the program stored in the ROM by accessing the RAM, and based on the calculation results, the DPCNTL 25
．． 5TCNTL26 and FLCNTL27 control the display and the shutter flash, and output a signal for lens control to PIO28.

FIG. 4 29 shows a connector CNCT, which performs communication between the camera and the lens. 30 is a read-only memory LROM that stores information unique to the photographing lens; 31 is a focal position control mechanism AFCNTL of the photographing lens;

32 is an aperture control mechanism APCNTL of the photographing lens.

LROM30 and AFCNTL included in the photographic lens
31, is connected to the camera's I'I○28 via APCNTL32 and CNCT29, and is connected to the camera's CPU22.
The reading or control mechanism is configured to be read out or to operate the control mechanism according to the instructions of the controller.

In this embodiment, as explained above, the photometry circuit AE
CKT17, flash mode selection switch FLSW1
8. Based on the input signals from the focus detection circuit AFCKT19 and the focus detection point selection switch AFSW20, the microcomputer is used to adjust the focus position of the camera's display device, shutter, flash, and photographic lens, and control the aperture. There is.

Next, the software configuration of the first embodiment of the present invention will be explained.

5 to 11 are flowcharts showing the software configuration of the first embodiment of the present invention, with FIG. 5 showing the main routine and FIGS. 6 to 11 showing each subroutine.

First, the main routine shown in FIG. 5 will be explained.

5 TEPOI: In the main routine camera, information corresponding to the brightness of the subject, information on the defocus amount of each of multiple focus detection points set in advance, flash mode selection information based on the photographer's will, and focus detection Control of focus position adjustment using point selection information and exposure control using shutter speed and aperture settings,
Handles flash control and display control. There are other items that the main routine should handle, such as quick return mirror drive control and film feeding mechanism control.
Here, only items related to the photometry device and flash photography control device of the camera of the present invention are taken out, and other items are omitted for the sake of simplicity.

5TEPO2: Take in signals of defocus amount of three focus detection points from AFCKTI9. The amount of defocus is determined by a pair of line sensors corresponding to each focus detection point, CCDLl and CCDL2, and CCDol and CCDc2.
, and by detecting the amount of deviation between the output signals of CCDR1 and CCDR□, and is captured as a digital signal.

The focus detection point selection signal from 5TEPO32 AFSW20 and the defocus amount signal from AFCKT19 are taken in, and if the photographer selects one focus detection point among the three focus detection points, that focus detection point If the photographer automatically selects the focus detection point by the camera, the focus detection point closest to the subject distance is detected from the three defocus amount signals, and the focus detection point is set to that focus detection point. This is a focus detection point selection subroutine that outputs a corresponding signal, and outputs a focus detection point signal SEL.

5TEPO4: The defocus amount to be adjusted is determined from the defocus amount signals of the three focus detection points and the above-mentioned focus detection point signal SEL, and the focus of the photographing lens is adjusted by the AFCNTL30.

5TEPO5: Take in signals corresponding to the brightness of 15 small areas and a digital signal from AECKT17.

5TEPO6: The signal taken from AECKT17,
The brightness signal of the object field corresponding to each small area is output after being appropriately corrected based on information specific to the photographic lens taken in from the LROM 29, and further, using these multiple brightness signals, the above-mentioned focus detection point is determined. Based on the signal SEL, the brightness signal A of the middle area including the focus detection point, the brightness signal B1 of the surrounding middle area, and the brightness signal C of the surrounding middle area are calculated. This is a subroutine that calculates the maximum value MAX of the luminance signals of the four luminance signals A described above.

Output B, C, MAX.

5TEPO7: A flash that takes in the input signal from the FLSW 18, determines whether or not flash photography should be performed based on the photographer's will or the camera's judgment of the subject situation, and outputs a signal FLSH indicating whether or not flash photography is to be performed. This is a shooting setting subroutine. The method of determining the scene situation using the camera will be described later.

5TEPO8: This is a photometric value calculation subroutine that inputs the brightness signals A, B, and C and the output signal FLSH of the flash photography setting subroutine, and outputs the photometric value E during natural light photography and flash photography.

5TEPO9: Determines the shutter speed and aperture value from the photometric value E based on the program preset in the camera, and outputs it.In addition to program mode, shutter priority mode, aperture priority mode, etc. It may also be possible to switch the shooting mode, and in either case, the shutter speed and aperture value are determined here based on those programs.

5TEPIO: The DPCNTL 25 displays exposure information such as shutter speed and aperture value, as well as focus detection point selection information, photometry mode selection information, flash use recommendation information, etc., on the display device of the camera as necessary.

5TEPII: Based on the shutter speed and aperture value determined as described above, the shutter speed is controlled by 5TCNTL26, the aperture of the photographing lens is controlled by APCNTL, and the flash FLA is controlled by FLCNTL.

With steps 5TEPO2 to 5TEPIl above, the series of shooting operations in the camera is completed, and in order to prepare for the next shooting operation,
Return to TEPO2 state.

Next, each subroutine will be explained.

FIG. 6 is a flowchart showing the 5TEPO3 focus detection point selection subroutine of FIG.

5TEP21: Focus detection point selection subroutine 5TEP
22: Import focus detection point selection information from the AFSW 20. AFSW uses the focus detection point selection signal AUT when the photographer sets the focus detection point to be automatically selected by the camera.
In the case where the photographer selectively sets one focus detection point, the focus detection point SL located on the left side of the shooting screen
When selected, a focus detection point selection signal FL is output,
When the focus detection point Sc located at the center of the shooting screen is selected, the focus detection point selection signal FC is output, and when the focus detection point SR located on the right side of the shooting screen is selected, the focus detection point selection signal FR is output. Output.

5TEP23: Determine whether the focus detection point selection signal is AUTO. 5TEP2 if AUTO
Proceed to 4, and if it is not AUTO, proceed to 5TEP25.

5TEP24: When the focus detection point selection signal is AUTO, the three focus detection points S L + SC+ are selected using the defocus amount signal output from AFCKT19.
The focus detection point where the subject distance is the shortest in the SR is identified, and the signal Nearest corresponding to the focus detection point is detected.
Output (FL, FC, FR).

5TEP25 Determine the focus detection point signal SEL in accordance with the focus detection point determined by selection by the photographer or automatic selection by the camera. The focus detection point signal SEL outputs one of PL, FC, and FR.

5TEP26: Return to the main routine.

FIG. 7 is a flowchart showing the 5TEPO6 area brightness calculation subroutine of FIG.

5TEP31: Photometric value calculation subroutine.

5TEP32: Digital signals Dog and Dc corresponding to the brightness of 15 small areas output from AECKT17
n.

B03. ..., import B15.

5TEP33: Retrieve information specific to the attached photographic lens from LROM33. The information unique to the photographic lens includes information such as the aperture F number of the photographic lens, focal length, exit pupil position, and peripheral light falloff when the aperture is fully open.

5TEP34 Using the information specific to the second photographing lens, AE
Correction data δo1 δ02. for correcting each of the 15 output signals from the CKT. ..., δ, 5 are determined, and a luminance signal for each small area is calculated. That is, the luminance signal VOI
, VO2, . . . V 15 are determined and output from the following formula: Note that the correction data δ01. δ [stock]
.

..., δ, and 5 are selected and determined from a table stored in advance in the ROM 23 based on the above-mentioned information specific to the photographic lens. It is also possible to calculate by calculation.

5TEP35: Determine whether the focus detection point signal SEL is the signal FL representing the focus detection point on the left side of the photographic screen. If 5EL=FL, proceed to 5TEP37 SEL≠F
If it is L, proceed to 5TEP36.

5TEP36: Determine whether the focus detection point signal SEL is a signal FC representing the focus detection point at the center of the photographic screen.

If 5EL=FC, proceed to 5TEP38, SEL≠F
If it is C, proceed to 5TEP39.

Classification is performed according to the focus detection point using 5TEP35 and 5TEP36, and when the focus detection point is on the left side, 5TEP35 and 5TEP36 are used.
Proceed to P37, and if the focus detection point is at the center, 5TEP38
In other cases, that is, when the focus detection point is on the right side, the process proceeds to 5TEP39.

5TEP37 to 5TEP39 classify the 15 classified small areas into three medium areas: the area near the focus detection point, the area around it, and the peripheral area around it, and calculate the average brightness of each medium area. It is calculated and output. At this time, 1
The five small areas are classified so that they are always included in one of the medium areas. The average brightness signal of each medium area is output as A1, which is the average brightness signal of the area near the focus detection point, B1, which is the average brightness signal of the surrounding area, and C, which is the average brightness signal of the surrounding area.

5TEP37: Determine the classification of the middle area when the left focus detection point is selected, and calculate the average brightness signal A of each middle area,
B and C are output based on the following equations.

A = V 07 B = (VO2+VO6+VQ8+V 12)/4C=
(V01+VO3+VQ4+VO5+VQ9+V10
10V 11 + V Is + V 14 + V 1
5)/L03TEP38: Determine the classification of the middle area when the central focus detection point is selected, and output the average luminance signals A, B, and C of each middle area based on the following equation.

A=Voa B= (VO3+VO7+VO9+V 13) /4C
= (Vow +V02+VO4+VO5+VO6+V
,.

+V o +V 12 +V 14 +V 15 )
/10 STEP 39: Determine the classification of the middle area when the right focus detection point is selected, and output the average luminance signals A, B, and C of each middle area based on the following equation.

A = V 09 B = (Vo, l+Vos+V 10 +V Is )
/4C= (V01+V02+V03+VO5+VO
6+VO7+ V n + V 12 + V 13 +
V +5) / l 05TEP40: Maximum value Max (Vo
w, VO2, VO3, -, VIs) is selectively determined and output as the maximum luminance signal MAX.

5TEP41: Return to the main routine.

As explained above, in the region brightness calculation subroutine, the region brightness signals A, B, C and the maximum brightness signal MAX are calculated.
is calculated and output.

FIG. 8 is a flowchart showing the flash photography setting subroutine of 5TEPO7 in FIG.

5TEP51: Flash photography setting subroutine.

5TEP52: Retrieve flash photography setting information from FLSW18. FLSW outputs a flash photography setting signal ON when the photographer sets to forcibly perform flash photography.
If the photographer sets the camera to automatically determine whether or not to perform flash photography, the flash photography setting signal AU
TO is output, and when the photographer forcibly sets not to perform flash photography, a flash photography setting signal OFF is output.

5TEP53: If the flash photography setting signal is ON, proceed to 5TEP55; otherwise, proceed to AUTOl
Or if it is OFF, proceed to 5TEP54.

5TEP54: If the flash photography setting signal is AUTO, proceed to 5TEP56; otherwise, proceed to 0
In the case of FF, proceed to 5TEP57.

5TEP53.5TEP54, the input signal from the FLSW is classified into three types: ON, AUTO, and OFF.

5TEP55: When the input signal from FLSW is ON, the flash setting signal FLSH is output as FLON.

5TEP56: This is a flash photography condition determination subroutine that determines whether or not flash photography should be performed depending on the luminance distribution of the subject when the input signal from the FLSW is AUTO. The flash photography condition determination subroutine receives the area brightness signal A and the maximum brightness signal MAX among the brightness signals output from the area brightness calculation subroutine of 5TEPO6 in FIG. When it is determined that it is necessary to perform the flash setting signal F
LSH is output as FLON, and when it is determined that flash photography should not be performed, the flash setting signal FLSH is output as FLO.
Output as FF.

5TEP57: Outputs the flash setting signal FLSH as FLOFF when the input signal from FLSW is OFF.

According to 5TEI'55 to 5TEP57, when flash photography is to be performed, the flash setting signal FLSH is output as FLON, and when flash photography is not to be performed, the flash setting signal FLSH is output as FLOFF.

5TEP58: Return to main routine.

FIG. 9 is a flowchart showing the 5TEP56 flash photography condition determination subroutine of FIG.

5TEP61: Flash photography condition determination subroutine.

5TEP62: Of the output signals of the area brightness calculation subroutine of 5TEPO6 in FIG. 5, the area brightness signal A and the maximum brightness signal MAX are input, and their brightness difference signal DEL is
Calculate TA using the following formula.

DELTA = MAX -A STEP 59: The brightness signal A in the middle area including the focus detection point is converted to a predetermined brightness signal RL set to the low brightness side (here, it is determined whether the situation is outdoors or indoors). The approximate brightness of the main subject is recognized by comparing it with the brightness of the main subject. A
>RL, that is, when it is determined that the situation is outdoors, the process proceeds to 5TEP63, and when A≦RL, that is, when it is judged that the situation is indoors, the process proceeds to 5TEP66.

5TEP63: The brightness signal A of the middle area including the focus detection point is further converted to a predetermined brightness signal R, 4 (
Here, it is assumed that the value is enough to distinguish whether the main subject is placed in the sun or in the shade outdoors. ), the approximate brightness of the main subject placed outdoors can be recognized in more detail. When A>RH, that is, when it is determined that the situation is outdoors in the sun, proceed to 5TEP65, and when A≦RH (therefore, R and A≦RH),
In other words, when it is determined that the situation is outdoors in the shade, 5T
Proceed to EP64.

5TEP64: Compare the luminance difference signals DEI and TA with a first predetermined value r1- for determining whether or not there is a backlight condition. When DELTA<rL, it is determined that there is no backlight condition, and the process proceeds to 5TEP68. When DELTA≧rL, it is determined that there is a backlight condition, and the process proceeds to 5TEP67.

5TEP65: Compare the luminance difference signal DELTA with a second predetermined value rH for determining whether or not there is a backlight condition. When DELTA<r□, it is determined that there is no backlight condition, and the process proceeds to 5TEP70. When DELTA≧rH, it is determined that there is a backlight condition, and the process proceeds to 5TEP69.

STEP6.3-5TEP65 determines whether the main subject is in a low-luminance state or in a backlit state by classifying it into the following five categories.

A≦RL; low brightness 5TEP66:
In the case of low brightness mentioned above. It is determined that flash photography should be performed, and the flash setting signal FLSH is output as FLON.

5TEP67: In the above-mentioned case of slightly high brightness or backlight, it is determined that flash photography should be performed and the flash setting signal FLSH is set to FLO.
Output as N.

5TEP68: In the above-mentioned case of slightly high brightness and priority, it is determined that flash photography should not be performed, and the flash setting signal FLS is
Output H as FLOFF.

5TEP69: In the case of high brightness and backlight as described above, it is determined that flash photography should be performed, and the flash setting signal FLSH is output as FLON.

5TEP70. In the case of high brightness and front lighting mentioned above, it is determined that flash photography should not be performed, and the flash setting signal FLSH is set to F.
Output as LOFF.

As explained above, in 5TEP66 to 5TEP70,
It is determined whether or not flash photography should be performed according to the situation of the scene classified by 5TEP63 to 5TEP65, and a flash setting signal FLSH is determined and output.

5TEP71, Return to flash photography setting/setting subroutine.

FIG. 12 shows a method for determining the flash photography conditions described above. In FIG. 12, one coordinate axis is the luminance difference signal DELTA.

The other signal is used as an area brightness signal A to identify the brightness distribution state of the object field. As described above, in this embodiment, flash photography is performed in the shaded area in FIG. 12, and natural light photography is performed in the non-shaded area. A method of determining the photographing situation based on the figure will be explained below.

(a) A≦RL (STEP 66) This is a case where the brightness signal A in the middle area including the focus detection point is smaller than the predetermined value RL set on the low brightness side, and it is determined that the main subject is placed indoors. . In such cases, the illumination light that illuminates the subject often has a different color temperature from outdoor natural light, such as fluorescent lights, and if you take a natural light photo using this illumination light, you will end up with extremely unnatural colored photographs. A problem arises in that the image is reproduced. Therefore, in such a case,
It is better to correct the color temperature by emitting flash light.

(b) RL<A≦RH1rL≦DELTA (ST
EP67) The brightness signal A in the middle area including the focus detection point is larger than the predetermined value RL set on the low-brightness side and smaller than the predetermined value RH set on the high-brightness side, and the brightness difference signal DE
This is the case when LTA is larger than the predetermined value rL. In such a case, the main subject is placed outdoors in the shade, and there is a large difference in brightness from the background, so it can be determined that the scene is a typical backlit scene. When shooting with natural light in such a backlit scene, the main subject will be considerably underexposed if you try to give an average suitable exposure to the entire frame, and if you try to give the main subject a suitable exposure In this case, the background portion will be considerably overexposed, and it will be difficult to give a somewhat suitable exposure to the main subject portion and the background portion at the same time. Therefore, in such a case, it is preferable to perform so-called daytime synchronized photography in which the main subject is illuminated with flash light and the background area that the flash illumination does not reach is photographed with natural light.

Here, the brightness difference signal DELTA is the difference between the maximum value MAX of the brightness signals of the 15 small areas and the brightness signal A of the small area including the focus detection point. The maximum brightness signal MAX extracts the brightness signal of a high-brightness subject such as the sky, clouds, or the sun placed within the shooting screen, and the area brightness signal A changes the area in conjunction with the selection of the focus detection point. Since the brightness of the main subject and its vicinity are extracted by , by using these differences, it is possible to relatively accurately determine whether the scene is a backlit scene.

(c) RL<A≦RHSDELTA<r L(ST
EP68) The brightness signal A of the middle area including the focus detection point is larger than the predetermined value RL set on the low brightness side and smaller than the predetermined value RH set on the high brightness side, and the brightness difference signal DE
This is the case when LTA is smaller than the predetermined value rL. In such a case, the main subject is placed outdoors in the shade, there are almost no high-luminance subjects such as the sky or clouds in the photographic screen, and there is relatively little variation in the luminance signal. In such a case, it is best not to use a flash, since good exposure can be obtained by natural light photography.

(d) RH<ASrH≦DELTA (STEP6
9) The brightness signal A of the middle area including the focus detection point is larger than the predetermined value RH set on the high brightness side, and the brightness difference signal DELT
This is a case where A is larger than the predetermined value rH, which is slightly smaller than the above-mentioned predetermined value rL. In such cases, the main subject is placed outdoors in the sun, and a subject with extremely high brightness such as sunlight or its reflected light is placed in the background, or a backlit scene with the sky or clouds in the background. Here, it is assumed that the main subject is somewhat small and the luminance signal A of the area including the focus detection point is already slightly influenced by the background and outputs a signal with a slightly higher luminance than the luminance of the main subject. Therefore, in such a case, it is better to emit flash light as in the case (b) and perform synchronized photography during the day.

Here, the predetermined values "H" and "rL" for determining whether or not it is a backlit scene are set as rH<rL.Generally, when it is determined that the scene is a backlit scene, there is a high brightness sky or clouds in the background. is arranged, but its brightness is a predetermined brightness (By8
Therefore, the brightness difference DELTA will be large in backlit scenes when the main subject's brightness is lower than the predetermined value RH, and in backlit scenes when the main subject's brightness is higher than the predetermined value RH. There may also be cases where the luminance difference DELTA does not become very large.

Also, assuming a backlit scene with the same brightness difference between the main subject and the background, if the main subject becomes slightly smaller, the brightness signal of the area including the focus detection point will be
It is influenced not only by the brightness of the main subject but also by the brightness of the background, and as a result, the area brightness signal A tends to become high and the brightness difference signal DELTA tends to become small.

Considering the phenomenon explained above, the predetermined value for determining whether or not it is a backlit scene is the predetermined value r on the high brightness side.
H and a predetermined value rL on the low luminance side are configured to have a relationship of rH<rL.

(e) RH<H, DELTA>r This is a case where the brightness signal A in the middle area including the H focus detection point is larger than the predetermined value RH set on the high brightness side, and the brightness difference signal DELTA is smaller than the predetermined value r□. . In such a case, the main subject is placed outdoors in the sun, and the shooting screen is almost uniformly high in brightness. In such a case, (
As in the case of C), it is best not to use a flash because good exposure can be obtained by natural light photography.

In this embodiment, as explained above, the situation of the scene is classified into five cases, and it is determined whether or not to emit flash light.

FIG. 10 is a flowchart showing the 5TEPO8 photometric value calculation subroutine of FIG.

5TEP81: Photometric value calculation subroutine.

5TEP82: Determine whether the flash setting signal FLSH is FLON. 5 when FLSH=FLON(7)
Proceed to TEP86, FLSH#FLON, that is, FLSH
= FLOFF, proceed to 5TEP83.

5TEP83: Since the natural light photography mode has been selected, evaluate light metering is calculated. 5TEP37-5TEP39
Average brightness signal A in the middle area near the focus detection point obtained by
, the average brightness signal B of the medium area around it, and the average brightness signal C of the medium area around it. Average luminance signal E. is calculated from the following formula.

E, = (A+B+C)/3 In the above equation, the three medium area luminance signals A, B, and C are simply added and averaged, but the area of the medium area near the focus detection point is S (A), The area of the middle region around it is S
(B), and the area of the middle region around it is S
(C), the area ratio of the three middle regions is S (A):
Since S(B):S(C)=l:4:10, by performing this calculation, the average brightness is calculated by weighting with a higher degree of emphasis near the focus detection point. At this time, the degree of emphasis of the three medium areas A, B, and C J (A)
, J (B), J (C) are proportional to the reciprocal of the area ratio, J (A) 2 J (B) : J (
c) = l: 0.25: 0.1. In the following explanation, E in the above equation will be used. The calculation for determining the value is called "focus detection point weighted average photometry."

5TEPP84: Area brightness calculation subroutine 5TEPO
By using the average brightness signal of the middle region obtained in step 6 and the difference between these average brightness signals, the shooting situation is estimated by analogy,
This is a correction value selection subroutine for selectively determining an exposure correction value α. Details will be described later.

5TEP85: For the focus detection point weighted average photometry E0 mentioned above,
Automatic exposure correction is performed by adding the exposure correction value α output from the correction value selection subroutine, and the photometric value E is determined by the following equation.

E=E o+α The photometric value E obtained by 5TEP83 to 5TEP85 is the photometric value obtained by evaluation photometry in this embodiment.

5TEP86: Since the flash photography mode has been selected in 5TEP82, photometric value calculation for flash photography is performed.

During flash photography, the main subject can be illuminated with a flash and adjusted to a suitable exposure level, so it is desirable to control the background so as to give a suitable exposure.

Therefore, in this embodiment, the area brightness calculation subroutine 5TE
By using the area brightness signals B and C output from PO6, a photometric value is determined by the following equation in order to give suitable exposure to the background area other than the main subject area.

E=(B+C)/2 In this embodiment, during flash photography, the photometric value is determined using the luminance signal of the surrounding area other than the area near the focus detection point selected as shown in the above equation.

It is assumed that the exposure is controlled using the above formula even in flash photography at low brightness, but in general, in the case of low brightness, AE calculations that do not make the shutter time too long are used to prevent camera shake, etc. is often performed using 5TEPO9 in FIG. 5, in which case the exposure is determined by another calculation and the above equation is not used.

5TEP87: Return to main routine.

As explained above, the photometric value calculation subroutine enables photometric value calculation that provides appropriate exposure for the main subject, the entire screen, or the background area, in conjunction with the selection of the focus detection point, both during natural light photography and flash photography. There is.

FIG. 11 is a flowchart representing the 5TEP84 correction value selection subroutine of FIG. 1O.

5TEPIOI: Correction value selection subroutine.

5TEP102: Using the average brightness signal A of the middle area near the focus detection point, the average brightness signal B of the surrounding middle area, and the average brightness signal C of the surrounding middle area, the brightness signal A of the adjacent middle area is calculated. and B, and the difference between B and C, ΔBA and ΔCB, are calculated from the following equations.

ΔBA=B-A ΔCB=-B STEP 103: Convert the average luminance signal C of the surrounding medium area to a signal K corresponding to a predetermined luminance (here, a signal K corresponding to an outdoor situation or an indoor situation) ) to recognize the approximate brightness of the scene. The reason why the average luminance signal C of the surrounding medium area is used here is that it is hardly affected by the reflectance of the main subject and is most suitable for estimating the situation in which the main subject is placed. When C≧, that is, when it is determined that the situation is outdoors, 5TE
The process advances to P104, and when C<K, that is, when it is determined that the situation is indoors, the process advances to 5TEPI21.

5TEP104: The average brightness of the surrounding medium area is a predetermined value ■
When it is determined that the brightness difference ΔBA is higher than that of an outdoor scene, first, the brightness difference ΔBA is compared with a predetermined value PH1 having a positive sign. If ΔBA<PH, proceed to 5TEP105,
If ΔBA≧P□1, the process advances to 5TEP106.

5TEP105: If ΔBA<PH, further ΔI
IA is compared with a predetermined value PH2 having a negative sign.

If ΔBA<PH□, proceed to 5TEP110 and set ΔBA
If ≧PH□, that is, P. If 2≦ΔBA<PH, the process proceeds to 5TEP108.

Brightness difference ΔBA due to 5TEP104.5TEP105
are classified into the following three types.

P) I+≦ΔBA; ΔBA is a positive value with a large absolute value PH□≦ΔBA<PH,; ΔBA is a small absolute value.

ΔBA P, 42; ΔBA is a negative value with a large absolute value.

5TEP106: If P H,≦ΔBA, ΔCB is further compared with a predetermined value Q141 having a positive sign. Δ
If CB<QHl, proceed to 5TEP107 and ΔCB≧
In the case of QHI, proceed to 5TEP112.

5TEP107: If ΔCB<QH Yu, further increase Δ
CB is compared with a predetermined value QH□ having a negative sign.

If ΔCB<QH2, proceed to 5TEP114 and check ΔCB
In the case of ≧QH2, that is, in the case of QH2≦ΔCB<QHI, the process proceeds to 5TEP113.

Brightness difference ΔCB due to 5TEP106.5TEP107
are classified into the following three types.

QH+≦ΔCB; ΔCB is a positive value with a large absolute value Q□2≦ΔCB<QHI; ΔCB has a small absolute value.

ΔCB<Q H2; ΔCB is a negative value with a large absolute value.

If 5TEP108.PH□≦ΔBA<PH, ΔCB is further compared with a predetermined value QH+ having a positive sign. Δ
CB<Ql (If +, proceed to 5TEP115, ΔCB
If ≧QH+, proceed to 5TEP109.

5TEP109: If ΔCB<Q)II, ΔCB is further compared with a predetermined value Q)+2 having a negative sign.

If ΔCI3<Q )+2, proceed to 5TEP117,
ΔCB≧Q) If 12, that is, Q, 42≦8CB<QH
If 1, proceed to 5TEpH6.

Brightness difference ΔCB due to 5TEP108.5TEP109
are classified into the same three ways as in 5TEP106.5TEP107.

5TEPIIO: If ΔBA<PH□, further ΔCB
is compared with a predetermined value QH+ having a positive sign. ΔCBkuQ
If HI, proceed to 5TEP118, ΔCB≧Q)+1
If so, proceed to 5TEPIII.

5TEPIII: If ΔCB<QHl, further Δ
CB is compared with a predetermined value QH2 having a negative sign.

If ΔCB<Q)+2, proceed to 5TEP120 and calculate ΔC
In the case of B≧Q, 42, that is, in the case of Q8□≦ΔCB<QHl, the process advances to 5TEP119.

Brightness difference ΔCB due to 5TEPIIO and 5TEPIII
are classified into the same three ways as in 5TEP106.5TEP107.

When 5TEP103 determines that it is an outdoor scene, 5TEP104 to 5TEP1 are
11, the situation of the photographic scene is classified into nine types, and the exposure correction value α is selected.

5TEP112 to 5TEP120: 5TEP104
Exposure correction values α suitable for the scene conditions classified by ~5TEPIII are respectively output. In this example, there are only three values of α: αH1, αH2, and 0 (however, α
H1〈αH2〈0), and among these three values,
Select one of them. A method for determining the exposure correction value α will be described later.

5TEP121: When the average brightness of the surrounding medium area is lower than a predetermined value and it is determined that the scene is an indoor scene, first, the brightness difference ΔBA is compared with a predetermined value PLI having a positive sign. If ΔBA<PL, proceed to 5TEP122,
If BA≧PLI, proceed to 5TEP123.

5TEP122: If ΔBA<PL, ΔBA is further compared with a predetermined value PL2 having a negative sign.

If ΔBA<PL2, proceed to 5TEP127 and set ΔBA
In the case of ≧PL2, that is, in the case of PL2≦ΔBA<PL, the process proceeds to 5TEP125.

By 5TEP121 and 5TEP122, the brightness difference ΔBA
are classified into the following three types.

PLI ≦ΔBA, ΔBA is a positive value with a large absolute value.

PL2≦ΔBA<PL,; ΔBA has a small absolute value.

ΔBA x PL2; ΔBA is a negative value with a large absolute value.

5TEP123: If PL, ≦ΔBA, further compare ΔCB with a predetermined value QLI having a positive sign. ΔC
If B<QLI, proceed to 5TEPI24 and ΔCB≧Q
In the case of LI, proceed to 5TEP129.

5TEP124: If ΔCB<QLl, further increase Δ
CB is compared with a predetermined value QL2 having a negative sign.

If ΔCB<Q L2, proceed to 5TEP131 and ΔC
If B≧QL2, that is, if QL2≦ΔCB<QLI, the process proceeds to 5TEP130.

Brightness difference ΔCB due to 5TEP123.5TEP124
are classified into the following three types.

QLI ≦ΔCB, ΔCB is a positive value with a large absolute value.

QL2≦ΔCB<Q Ll; ΔCB has a small absolute value.

ΔCB<QL□; ΔCB is a negative value with a large absolute value.

5TEP125: If PL2≦ΔBA<PL, ΔCB is further compared with a predetermined value QL+ having a positive sign. If ΔCB<Q Ll, proceed to 5TEP126,
If ΔCB≧QLI, proceed to 5TEP132.

5TEP126: If ΔCB<QLI, further Δ
CB is compared with a predetermined value QL2 having a negative sign.

If ΔCB<QL2, proceed to 5TEP134 and check ΔCB
In the case of ≧QL2, that is, in the case of QL2≦ΔCB<QLI, the process proceeds to 5TEP133.

Brightness difference ΔCB due to 5TEP125.5TEP126
are classified into the same three ways as in 5TEP132.5TEP124.

5TEP127: If ΔBA<P L2, further Δ
CB is compared with a predetermined value QLI having a positive sign. ΔCB
If <QLI, proceed to 5TEP128 and ΔCB≧QL
If it is +, proceed to 5TEP135.

5TEP128: If ΔCB <Q' t, +, ΔCB is further compared with a predetermined value QL2 having a negative sign.

If ΔCB<Q L2, proceed to 5TEP137 and ΔC
If B≧QL2, that is, if QL2≦ΔCB<QLI, the process advances to 5TEP136.

5TEP127.5TEP128, brightness difference ΔCB
are classified into the same three ways as in 5TEP123 and 5TEP124.

When 5TEP103 determines that the scene is an indoor scene, 5TEP121-5TEP1
28, the situation of the photographic scene is classified into nine types and the exposure correction value α is selected.

5TEP129-5TEP137: 5TEP121
~5 Exposure correction values α suitable for the scene conditions classified by the TEP 128 are respectively output. In this example, the value of α is limited to three values: αLI%αL2 and 0 (however, α
L1〈0〈αL2), and among these three values,
Select one of them. A method for determining the exposure correction value α will be described later.

5TEP138: Return to photometric value calculation subroutine.

In the correction value selection subroutine, as explained above, the situation of the object scene is estimated and an appropriate correction value α is output.

Next, a method for determining the exposure correction value α will be explained.

5TEP112 to 5TEP120 and 5T in Figure 11
ΔBA represents the 18 states classified into EP129 to 5TEP137.

When ΔCB is expressed in a coordinate plane with both coordinate axes, it becomes as shown in FIGS. 13(a) and 13(b). Also, 5 in Figure 11
TEP112~5TEP120, and 5TEP129~
The state of STEP 137 is that the brightness signal A of each medium area,
Figure 14 (a) and (b) show B and C in bar graphs.
)become that way. FIG. 14 shows the focus detection point weighted average photometric value E in each situation. , the exposure correction value α, and the evaluation photometric value E are also schematically shown. The situation of the field under each condition and the method for determining the exposure correction value α will be explained below with reference to FIGS. 13 and 14.

(a) When K≦C: Outdoor scene (a-1)
PH1<ΔBA, QHI<ΔCB (STEP 112) As shown in FIG. 13(a), ΔHA is a positive predetermined value P.
This is a case where ΔCB is larger than H1 and larger than a positive predetermined value QH+, and the brightness distribution is as shown in (i) of FIG. 14(a). In this case, the background part is high brightness and the main subject part is relatively low brightness.
It can be generally assumed that this is a backlit scene. Moreover, since the brightness signal A, brightness signal B, and brightness signal C change in stages, the main subject placed near the focus detection point is the area where the brightness signal A is output and the area where the brightness signal B is output. It is thought that it exists in some parts of the world. In the case of such a brightness distribution, the focus detection point weighted average photometric value Eo will be output as shown in the figure. In order to provide exposure, use the correction value α, 41, which has a negative sign and has a relatively large absolute value, as shown in (i) in Fig. 14(a).
It is preferable to output the evaluation photometric value E as shown in FIG.

(a-ii) PH1<ΔB A% Q H2<Δ
CB≦QHI (STEP 113) As shown in FIG. 13(a), ΔBA is a positive predetermined value P.
. In such a case as well, it can be estimated that the scene is a backlit scene, as in case (i). Looking at the variations in the brightness signals, only the brightness signal A has a relatively low brightness, and it is thought that the main subject is placed only in the area where the brightness signal A is output. In addition, in such a case, the size of the main subject may be approximately the same as the area that outputs the brightness signal, or it may be slightly smaller than this area, and in the former case, the brightness difference ΔBA is In the latter case, the brightness signal A itself is already influenced by the background brightness, and the brightness difference ΔBA tends to become relatively small. In either case, if the brightness difference ΔBA is larger than the positive predetermined value PHI and it is detected that a main subject with relatively low brightness is placed near the focus detection point, focus detection as shown in the figure is performed. Point-weighted average photometric value E. In contrast, while fully considering the brightness of the main subject and also taking into account the brightness of the background, the correction value α8 for case (i) and between roads, etc.
+ is used to output the evaluation photometric value E, which is good GA0 (a
-4ii) PH,<ΔBA, ΔCB≦Q)12(S
TEpH4) As shown in FIG. 13(a), ΔBA is a positive predetermined value P.
This is a case where ΔCB is larger than H1 and smaller than a negative predetermined value QH2, and the brightness distribution is as shown in (iii) of FIG. 14(a). Such a brightness distribution appears when a locally high-brightness object exists in the area where the brightness signal B is output. In such a case, if you correct the effect of this local high-brightness subject, it will be possible to give a suitable exposure to the entire screen.
As shown in (iii) of FIG. 14(a), using the correction value α8□ with a negative sign and a relatively small absolute value,
It is preferable to output the evaluation photometric value E.

(a-iv) PH2<ΔBA≦PHISQH1×ΔCB (STEP 115) As shown in FIG. 13(a), ΔBA is a negative predetermined value P.
Greater than 8□ and smaller than the positive predetermined value PH1, ΔC
In the case where B is larger than the positive predetermined value QH+, FIG.
This is the case of a brightness distribution as shown in (jv) of ).

In such a case as well, it can be estimated that the scene is a backlit scene, as in case (i). Looking at the variations in the brightness signals, we see that brightness signals A and B are lower in brightness than brightness signal C, and the main subject is divided into an area that outputs the brightness signal and an area that outputs the brightness signal B. It is thought that they are located over a fairly wide area. In the case of such a brightness distribution, it is preferable to output a photometric value that places more emphasis on the area determined to be the main subject, but the focus detection point weighted average photometric value E. As shown in the figure, since it is affected to some extent by the brightness of the high-brightness background area, it is preferable to output the evaluation photometric value E using the case (iii) and the correction value αH2 for road gaps, etc.

(a-v) PH2<ΔBA≦PH1, Q+(2<ΔCB≦QHI (STEP116) As shown in FIG. 13(a), ΔBA is a negative predetermined value P
greater than H2 and smaller than a positive predetermined value P)11;
This is a case where ΔCB is larger than the negative predetermined value Q, 42 and smaller than the positive predetermined value QH+, and the brightness difference is small as shown in (V) of FIG. 14(a).

This kind of brightness distribution occurs in backlit scenes similar to case (ii), where the size of the main subject has become even smaller and it is difficult to detect the brightness of the main subject, and (iv). ), but the size of the main subject is even larger, such as a landscape scene where the main subject takes up almost the entire screen. Even in the case of a backlit scene where the main subject is small, it is better to treat it as a backlit landscape scene under these circumstances.Therefore, in order to give an appropriate exposure to the entire screen, the correction value is set to 0, and focus detection point weighted average metering is used. Value E. It is better to output the evaluation photometric value E as it is.

(a vi) PH2<ΔBA≦PH1%ΔCB≦
QH2 (STEP 117) As shown in FIG. 13(a), ΔBA is a negative predetermined value P.
Greater than H2 and smaller than a positive predetermined value PH1 (, ΔC
This is the case where B is smaller than the negative predetermined value Q)12, and the brightness distribution is as shown in (vi) of FIG. 14(a). Such a brightness distribution appears when a main subject with fairly high brightness is placed in both the area where brightness signal A is output and the area where brightness signal B is output, and in many cases, With respect to the luminance signal C indicating general brightness outdoors, the main subject with considerably high luminance is a subject with high reflectance (whitish). Therefore, in such a case, it is better to output the evaluation photometry value E using the case of (jji) and the correction value αH2 for the distance, etc., as shown in the figure, so that the main subject part is depicted as whitish to some extent. .

(a-vii) ΔBA≦PH2, QHl<ΔC
B (STEP 118) As shown in FIG. 13(a), ΔBA is a negative predetermined value P.
This is a case where ΔCB is smaller than H2 and larger than a positive predetermined value QHI, and the brightness distribution is as shown in (vii) of FIG. 14(a). This kind of brightness distribution appears when the main subject itself has a considerable contrast ratio, or when a landscape scene has a special composition, but these are not very common scenes (and are often There are also few.

In such a case, it is better to give appropriate exposure to the entire screen, and as in case (v), set the correction value to O.
, focus detection point weighted average photometric value E. It is better to output the evaluation photometric value E as it is.

(a-viii) Δ BA ≦ PH2,
Q H2< Δ CB ≦Q) II (STEP 119) As shown in FIG. 13(a), when ΔBA is a negative predetermined value P
H2, ΔCB is larger than the negative predetermined value QH2, and smaller than the positive predetermined value Q)+1, and the luminance distribution is as shown in (viii) of FIG. 14(a). In such a case, as in case (vi),
It can be estimated that the main subject is a subject with high reflectance (whitish). Further, in such a case, it can be determined that the size of the main subject portion is smaller than in the case (vi). In the case of such a subject, it is necessary to depict the main subject part as whitish to some extent, but as shown in the figure, the focus detection point weighted average photometric value E. If used as is, it is possible to give the desired exposure, so it is better to output the evaluation photometric value E using the correction value 0.

(a-ix) ΔBA≦PH□, ΔCB≦QH2
(STEP 120) As shown in FIG. 13(a), ΔBA is a negative predetermined value P.
This is a case where ΔCB is smaller than a negative predetermined value Q)12, and the brightness distribution is as shown in (ix) of FIG. 14(a). In this case, it is presumed that the subject is the same as in case (vi), and it can be determined that the size of the main subject is intermediate between cases (vi) and (viii). In addition, in such a case, the area near the focus detection point is even more bright than in cases (vi) and (viii), and there may be a subject with a higher reflectance, or there may be some kind of light source. It can be determined that if the In such a case, the focus detection point weighted average photometric value E is used as shown in the figure. Even if you use it as is, the main subject will be washed out to some extent (
However, considering the balance with the peripheral areas of the screen, the main subject area is depicted more whitish (iii
) and the road distance correction value αH2 to output the evaluation photometric value E.

(b) When C<K: Indoor scene (b t) PLI<ΔBA, QLI<ΔCB(S
TEP129) As shown in FIG. 13(b), ΔBA is a positive predetermined value PL.
This is a case where 8CB is larger than I, and 8CB is larger than a positive predetermined value QL+, and the brightness distribution is as shown in (i) of FIG. 14(b). In such a case, the background part is not very bright and the main subject part has a much lower luminance than the background part, so the main subject is placed in a position that is not illuminated by the indoor lighting. Scenes etc. are assumed. Furthermore, a scene in which a somewhat low reflectance (darkish) object is placed near the focus detection point is also assumed. Further, the size of the main subject is considered to exist over part of the area where the brightness signal A is output and the area where the brightness signal (b) is output, similar to (a-i).

Under such conditions, in order to depict the situation of the subject observed by the photographer in accordance with the photographer's sensibilities, the main subject should be rendered slightly darker to the extent that the details are not lost. It is desirable to provide such exposure.

Therefore, as shown in (i) of FIG. 14(b), the focus detection point weighted average photometric value E. , the correction value α1. has a negative sign and has a relatively small absolute value. It is preferable to obtain the evaluation photometric value E using .

(b-ii) PLl<ΔBAS Q L2 <Δ
CB≦QLI (STEP 130) As shown in FIG. 13(b), ΔBA is a positive predetermined value P.
14 (
This is a case of a brightness distribution as shown in (ii) of b). In such a case, as in case (i), it can be estimated that the main subject is a dark scene. Furthermore, the size of the main subject can be determined to be slightly smaller than in case (i), similar to case (a-ii). Even in such a case (i
), it is desirable to render the main subject part slightly darker, so as shown in (i)
It is preferable to output the evaluation photometric value E using the correction value αLl for the road gap and the like.

(b-iii) I'L<ΔBA1ΔCB≦QL2(
STEP 131) As shown in FIG. 13(b), ΔBA is a positive predetermined value P.
This is the case where 8 CB is smaller than the negative predetermined value QL2, and the luminance distribution is as shown in (iii) of FIG. 14(b). Such a luminance distribution appears as follows. , when there is a locally high-luminance object such as an illumination light source in the area where the luminance signal B is output.In such a case, the focus detection point weighted average photometric value E. In order to provide suitable exposure for such a scene where the main subject appears somewhat dark due to the influence of the high-brightness area, the correction value is set to 0 and the focus detection point weighted average photometric value E is set as shown in the figure. It is preferable to output .as is as the evaluation photometric value E.

(b +v) PL2 <ΔBA≦PL1, QL
I<ΔCB (STEP 132) As shown in FIG. 13(b), ΔBA is a negative predetermined value P.
larger than L2 and smaller than a positive predetermined value PLI,
This is a case where ΔCB is larger than a positive predetermined value QL+, and the brightness distribution is as shown in (iv) of FIG. 14(b). In such a case, as in case (i), it can be estimated that the main subject is a dark scene. Further, as in (a-iv), the size of the main subject is larger than in case (i), and it can be determined that it is arranged over a fairly wide area of the photographic screen. Even in such a case, it is desirable to depict the main subject part slightly blackish as in the case (i), but the focus detection point weighted average photometric value E is used as shown in the figure. is a value that gives a fairly suitable exposure even as it is, so by setting the correction value to O,
Focus detection point weighted average photometric value E. It is better to output it as is as an evaluation photometric value.

(b-v) PL2<ΔBA≦PLI, QL2<ΔCB≦QL2 (STEP 133) As shown in FIG. 13(C), ΔBA is a negative predetermined value P.
Greater than L2 and smaller than the positive predetermined value PLI, Δ
CB is larger than the negative predetermined value QL2 and is a positive predetermined value Q
This is a case where the luminance difference is smaller than LI, as shown in (v) of FIG. 14(b).

Such a brightness distribution appears in situations similar to (a-v), but especially in indoor scenes, bright and dark areas coexist within each area, and brightness signals A, B, and C are output as middle areas. As a result, there are many scenes where the brightness difference becomes small. In such a case, as in (a-v), set the correction value to 0 to give proper exposure to the entire screen,
Focus detection point weighted average photometric value E. Evaluate the photometric value E as it is
It is better to output it as

(b-vi) PL2<ΔBA≦PLI, ΔCB≦Q
L2 (STEP 134) As shown in FIG. 13(b), ΔBA is a negative predetermined value P.
Greater than L2 and smaller than the positive predetermined value PLI, Δ
In the case where CB is smaller than the negative predetermined value QL2, FIG.
This is a case of a brightness distribution as shown in (vi) of b). Such a brightness distribution appears because the main subject exists in both the area where the brightness signal A is output and the area where the brightness signal B is output, the main subject is illuminated by the illumination light, and the other background areas are This is the case when the brightness is relatively high. In such a case, you may want to focus on the main subject while also taking into account the luminance signal of the background.
In order to provide suitable exposure, it is preferable to output the evaluation photometric value E using a correction value αL2 having a positive sign, as shown in the figure.

(b-vii) ΔBA≦PL2, QLI<ΔC
B (STEP 135) As shown in FIG. 13(b), ΔBA is a negative predetermined value P.
This is a case where ΔCB is smaller than L2 and larger than a positive predetermined value QL+, and the brightness distribution is as shown in (vii) of FIG. 14(b). Similar to (a-vii), such a brightness distribution appears under special circumstances,
In this case, as in (a-vii), it is better to give an appropriate exposure to the entire screen (therefore, the correction value is set to 0, and the focus detection point weighted average photometric value E is used for evaluation. It is best to output it as a photometric value E.

(b-viii) ΔBA≦PL2, QL2kuΔ
CB≦QLI (STEP 136) As shown in FIG. 13(b), ΔBA is a negative predetermined value P.
This is the case where ΔCB is larger than the negative predetermined value QL2 and smaller than the positive predetermined value QL+, and the luminance distribution is as shown in (viii) of FIG. 14(b). In such a case, as in case (■1), it can be assumed that the scene is such that only the main subject is relatively bright due to illumination light, etc.
The size of the main subject portion can be determined to be smaller than in case (vi) from the distribution state of the luminance signal. In such a case, in order to give an exposure that takes into account the luminance signal of the background to some extent while emphasizing the luminance signal of the main subject part, (vi ), it is preferable to output the evaluation photometric value E using the correction value αL2 for the road gap, etc.

(b-ix) ΔBA≦PL2, ΔCB≦QL2
(STEP 137) As shown in FIG. 13(b), ΔBA is a negative predetermined value P.
This is a case where ΔCB is smaller than a negative predetermined value QL2, and the luminance distribution is as shown in (ix) of FIG. 14(b). In this case, it is presumed that the subject is the same as in case (vi), and the size of the main subject can be judged to be intermediate between cases (vi) and (viii). . Also, in this case, compared to cases (vi) and (viii),
The area near the focus detection point has even higher brightness, and the main subject illuminated by the illumination light has a slightly high reflectance (slightly whitish), or the main subject is illuminated behind or near the main subject. A scene in which a light source is placed is assumed. In such a case, in order to render the area near the focus detection point a little whitish and give an exposure that takes into account the balance of the entire screen while emphasizing the main subject, use (Vi) as shown in the figure. It is preferable to output the evaluation photometric value E using the correction value αL2 for the distance and road distance.

As explained above, in this example, the situation of the subject is
The configuration is such that the exposure correction value α is classified into eight types and the optimum exposure correction value α is selectively determined under each condition. Note that the magnitude relationship of the above-mentioned exposure correction values can be summarized as follows.

αH1<α□2<0 αL, <0<αL2 Also, regarding the magnitude relationship between α□ or αH2 and αL1, the predetermined value PHr l PH2I Q)l I+
QH2*PLII PL21 QLII It differs depending on the setting of QL2, but when compared when the brightness differences ΔBA and ΔCB are values such as between roads, it is generally desirable to set α8□<αL1.

In the method for determining the exposure correction value α explained above, in order to simplify the explanation, the scene was classified in nine ways based on the brightness difference ΔBA and ΔCH. ), (ii) and (v), where the selection result of the exposure compensation value α changes greatly depending on the brightness difference, it is especially important to perform more detailed classification. It is desirable to do so. Furthermore, even when classifying the object scene based on the luminance signal C, it is desirable to perform more detailed classification. In this way, the subject is
More detailed classification makes it possible to reduce unevenness in exposure when there is a slight change in the photographic composition and to obtain stable exposure.

A photometric device configured to output an appropriate photometric value by analogizing the situation of the object using the luminance signal differences ΔBA and ΔCB and the luminance signal C at the periphery of the photographic screen is disclosed by the same applicant. It is disclosed in Japanese Unexamined Patent Publication No. 184319/1983.

In addition, the focus detection point weighted average photometry in this embodiment is an operation for calculating an average value using the importance of the luminance signal of the divided small area as a coefficient according to the position of the selected focus detection point. , when the left focus detection point is selected, when the center focus detection point is selected, and when the right focus detection point is selected, the coefficients of the importance of each area are shown in FIGS. 15(a) and (b), respectively. ).

It looks like (c). It goes without saying that the combination of importance coefficients is not limited to this.

Furthermore, in the above embodiment, the flash photography conditions were classified into three stages based on the value of the brightness signal A in the area near the focus detection point.
It goes without saying that a more detailed classification would be even more effective. In addition, in the description of the above embodiment, the luminance difference DEL
Although TA is compared with a predetermined value only when the brightness is high, it can also be considered that it is compared with a predetermined value O even when the brightness is low, and the flash light emission conditions are determined based on the brightness A of the predetermined area. When comparing the brightness difference DELTA, set the predetermined value to 0°r.
It can also be characterized as the flash light emission condition being determined by changing it into three stages: L+r)l.

[Other Examples]

FIGS. 16(a) and 16(b) are diagrams showing divided shapes of a photometric light receiving section according to another embodiment of the present invention. In the first embodiment of the present invention, the photometric light receiving section is divided into 15 small areas of the same shape, but it may be divided into small areas of different shapes and areas as shown in FIG. 16. However, in such a case, when classifying the luminance signal of a small area into a medium area, care must be taken so that the area of each medium area does not change significantly due to the selection of the focus detection point.

In Figures 16(a) and (b), the field of view is 11
However, reducing the number of divisions has the advantage of simplifying the photometry circuit and reducing the cost of the light receiving element for photometry. be. In addition, when the light-receiving section for photometry is divided as shown in Fig. 16, the small light-receiving areas placed around the periphery of the photographic screen are further connected in series to reduce the actual number of divisions of the light-receiving section for photometry. , it can also be less. A technique for reducing the number of divisions of the photometric light-receiving section in this way is disclosed in Japanese Patent Application Laid-Open No. 125527/1983 filed by the same applicant.

〔Effect of the invention〕

As explained above, the present invention divides a field into multiple regions, outputs a luminance signal for each region, and calculates the maximum value of these luminance signals and the luminance including the focus detection region determined according to the selection. By using the signal, it is possible to relatively accurately detect whether the main subject is in a backlit state, and based on this, a display recommending flash firing is displayed on the camera's display device. Alternatively, it is also possible to provide a camera that automatically fires a flash.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the divided shape of the photometric light receiving section of the first embodiment of the present invention, FIG. 2 is a sectional view of the optical system of the camera of the first embodiment of the present invention, and FIG. 3 is a diagram of the present invention. A perspective view of a multi-point focus detection optical system according to the first embodiment; FIG. 4 is a diagram showing the circuit configuration of a camera according to the first embodiment of the present invention; FIGS. Flowchart, FIGS. 12 to 15 are explanatory diagrams for explaining the flowchart of the first embodiment of the present invention, and FIG. 16 is a diagram showing the divided shape of the photometric light receiving section of another embodiment of the present invention. . 6...Photometry light receiving section 15...Focus detection light receiving section 22...Central processing unit CPU 5 horn S/2 S/J S/Riyari ACB Figure 74 (a) (Vii) C3TEF' urt) civ) C5rEPtis) ci) (srr:puz) (viii) (STEP//f) (V)C5rEPn6) (ii) (5TEFI/3) tir) C3r11Ptro) (Vi) (5了EFnri) (jii ) (5TEP114) (Vii) tSTEP13! D CIV) (STEPljZ) (1) ζSEE/'/η) (viii) (5y-pnb) <V) CSTEPtn) (ii) (5πP/shi) (IX) C3TEP/n) CV+) C5'TEF/M ) 6ii) (8 lower pty)

Claims (1)

[Claims] (1) In a camera equipped with a focus detection means configured to be able to independently detect the focus of multiple areas within the shooting screen, the subject is divided into multiple small areas for photometry, and each of the divided small areas is light receiving means for detecting brightness; detection area selection means for selecting one of a plurality of focus detection areas; brightness information of the small area including the focus detection area selected by the detection area selection means; Based on the comparison information that compares the maximum brightness information within multiple small areas,
A camera comprising: a light emission determining means for determining flash light emission.