JPH03223826A - Camera - Google Patents

Abstract

PURPOSE:To accurately perform the photometry of a main object with excellent operability by automatically using the brightness information of a small area including a selected focus detecting area as a photometric value in the case of performing partial photometry. CONSTITUTION:A field is divided into plural small areas S01-S15 for photometry, and photodetector means SPD, AMP and DI for detecting the brightness of every divided small area and a photometric mode selection means AESW 18 capable of selecting a 1st photometric mode in which the brightness information of one part in a photographing image plane is used as the photometric value and a 2nd photometric mode in which the photometric value is obtained by various arithmetic operations based on the brightness information of the entire photographing image plane are provided. A detecting area selection means AFSW 20 for selecting one of the plural focus detecting areas and a control means which uses the brightness information of the small area including the focus detecting area selected by the means AFSW 20 as the photometric value when the 1st photometric mode is selected by the means AESW 18 are also provided. Thus, the operability, especially in the case of deciding exposure at photographer's wil, is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention includes a focus detection device capable of independently detecting the focus of multiple regions of a photographic field, and also divides the photographic field into multiple regions and performs photometry. The present invention relates to a camera having a photometric device.

[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 appropriate 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, photometry is performed by dividing the field into a central area and a plurality of outer areas that are divided into two or more areas and arranged to surround the central area, and Standardize the brightness of each area with a reference value set between the maximum and minimum brightness values of the area, classify the subject based on this normalized output, and calculate the photometric value from the classified output. We are proposing a photometric 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.

Furthermore, 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 divided into the area at the center of the screen, the area outside of the center, and the area outside of the center of the screen. The main subject is divided into at least three regions, and the approximate size of the main subject and the shooting situation are simultaneously determined based on the luminance signals of these multiple regions and the difference in luminance signals between adjacent regions, and the appropriate exposure is determined. We are proposing a photometric device that gives In this publication, the approximate size of the main subject is determined using the difference in luminance signals, so compared to methods that estimate the size of the main subject using photographic magnification, it depends on the actual size of the main subject. This has the advantage of making it possible to stably obtain appropriate exposure.

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. be.

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 point detection devices has a The main subject is also likely to be placed in a specific area other than the center of the screen.

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 1li-sensing for the photometric area, the brightness of the main subject is accurately determined, and this is output as a photometric value for natural light photography.

[Problem that the invention is trying to solve]

Note: Among the conventional photometering devices, one configured to be suitable for a camera equipped with a distance measuring device capable of independently measuring distances from multiple points in the subject is disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 1-2027.
Only Publication No. 20 is available. Although this publication includes the idea of considering the in-focus state of multiple distance measuring points, the basic technical idea is that the field of view is taken into account when calculating photometric values according to the shooting magnification. The method disclosed in Japanese Patent Laid-Open No. 61-279829, which attempts to accurately determine the brightness of the main subject by changing the area, is used.

Therefore, if the actual size of the main subject is different from the originally expected size, the brightness of the main subject will be incorrectly measured, making it difficult to obtain the correct exposure. The shortcomings of the device are also being followed. In addition, the technical concept of changing the field of view considered when calculating photometric values according to the shooting magnification in this way also makes it difficult to determine whether a narrow area should be judged as the main subject when the shooting magnification is small (when the shooting magnification becomes small), or A discontinuous point occurs in the shooting situation judgment of whether almost the entire area of the subject should be judged as the main subject.Also, if the difference in brightness between the distance measurement target area and other areas is large, the result of this judgment There was also a problem in that the photometric value changed greatly due to this.

Therefore, when the photographer decides the exposure by inputting his/her own will, this metering value is difficult for the photographer to understand (and is unstable, so it is very problematic). Therefore, in cameras that output evaluation light metering values in this way, a partial light metering value that averages the light of a portion of the shooting screen is used as a light metering value that is suitable for determining exposure based on the photographer's input. There has also been proposed a configuration in which the photometric value to be output is selected by switching the photometry mode to evaluative photometry or partial photometry.

In such cameras, the photometry area for partial photometry is generally set at the center of the photographic screen.

This is because the subject to which partial photometry is performed is generally the main subject, and most of the main subjects are located near the center of the photographic screen. Now, if we assume a distance measuring device that can measure distances at multiple points within the shooting screen, it is likely that the main subject will be placed near the focusing point, and there will also be distance measuring devices in areas other than the center of the shooting screen. Because the points are arranged, there is a problem in that if a focus point other than the center of the shooting screen is selected, partial metering that measures a predetermined area in the center will be difficult to operate. Ta.

[Means to solve 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 field of view is divided into multiple small areas for photometry, and the brightness of each of the divided small areas is detected. a first photometry mode that uses luminance information of a part of the shooting screen as a photometric value; and a second photometry mode that calculates a photometric value by various calculations based on the brightness information of the entire shooting screen.
a photometry mode selection means that can select a photometry mode; a detection area selection means that selects one of a plurality of focus detection areas; and in the photometry mode selection means, when the first photometry mode is selected; , characterized in that the camera is equipped with a control means that uses luminance information of the small area including the focus detection area selected by the detection area selection means as a photometric value, and is particularly suitable for operations when determining exposure according to the photographer's will. It is possible to provide a camera with improved performance.

〔Example〕

1 to 12 are diagrams showing a first embodiment of the present invention, and represent a photometry device for a camera having three focus detection areas.

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, Sol, SO2...S 115
represents a plurality of light-receiving small areas divided into 15 areas, and S
L, Sc, and SR represent the focus detection field of view projected onto the field of view, similar to the photometric light receiving section. In this example, as shown in Fig. 1, the subject field is divided into three focus detection areas (the focus detection method includes a method that detects the amount of defocus in the previous focused state, and a method that detects the amount of defocus in the previous focused state, and a method that detects the amount of defocus in the previous focused state, and There are methods for detecting the distance of a subject. photometry is being carried out.

FIG. 2 is a diagram showing the optical arrangement of the first embodiment of the present invention,
In the figure, 1 is a photographing lens, 2 is a quick return mirror, 3 is a focusing plate, 4 is a penta-dahab rhythm, 5 is an imaging lens for photometry, 6 is a photoreceptor for photometry, 7 is an eyepiece lens,
8 is the pupil position, 9 is the submirror IO is the field of view mask, 11
12 is a condensing lens, 12 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 area into areas, and the focus of a part of the subject image formed near the field of view mask IO placed near the planned imaging plane of the photographic lens 1 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.

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

FIG. 4 is a block diagram showing the circuit configuration of the first embodiment of the present invention. In the same figure, S P Do+ , S
P D 02..., SPD, , are the 15 light receiving small areas S o+ and S 02 shown in FIG. 1, respectively.
...Silicon photodiode that measures +S+S (
SPD), which generates a photocurrent according to the brightness of each small area. AMPo+.

AMPoz-, AMP+l+ and DIOI, DIO
2,.=r DI +5 are an operational amplifier and a compression diode, respectively, and a silicon photodiode (S
PD), an operational amplifier, and a compression diode are combined to constitute light receiving means corresponding to the 15 light receiving small areas shown in FIG. 17 is a photometric circuit AECKT, which outputs output signals corresponding to the brightness of a plurality of light receiving small areas, respectively.
/D conversion and output as a digital signal.

Reference numeral 18 denotes a metering mode selection switch AESW, which allows the camera to automatically determine the appropriate exposure for the shooting screen according to the operator's will, depending on the brightness distribution of the subject, and The brightness signal of a specific area is output, and based on this, the operator can select any one of the partial photometry modes in which exposure is determined by making use of experience. 15 is a focus detection light receiving unit corresponding to FIG. 3, and CCDL, CCDL2, CCDo, CCDo2, CCI)R, and CCDR□ are focus detection visual fields SL and S in FIG. 1, respectively. , SR are three pairs of light receiving element arrays. ■The pair of light-receiving element arrays uses the optical system shown in FIGS. 2 and 3 to generate a T
It is configured so that only the light flux that has passed through the two areas that has been formed is extracted and formed into an image, and by comparing the output signals from these pair of light receiving element arrays, it is possible to detect the amount of defocus. 19 is the focus detection circuit AFCKT
Based on the output signals from the three pairs of light receiving element arrays provided in the focus detection light receiving section 15, the objects corresponding to the three focus detection visual fields SL, So, and SR in FIG. 1 are detected as described above. The amount of defocus in the photographic field is detected, and information on the three defocuses li1 is output as a digital signal. 20 is a focus detection point selection switch AFSW, which selects the three focus detection fields SL of FIG. 1 according to the will of the operator.

An automatic selection mode in which the camera automatically determines a suitable focus position on the shooting screen according to the distribution of defocus amount in the field corresponding to So and SR, and three focus detection fields of view shown in Figure 1. The operator can select any one of the optional selection modes in which the focus detection field of view is selectively determined, and furthermore, in the optional selection mode, the focus detection point selection switch selects the focus detection point selection switch. It is configured so that it can indicate points. In Figure 4, photometric circuit A
ECKT17, metering mode selection switch AESW18,
Input signals from the focus detection circuit AFCKT19 and the focus detection point selection switch AFSW20 are input to the microcomputer.
It is connected to the internal data bus line BUS21 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, 22 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 and 27 are general-purpose input/output ports PIO, and are connected to the internal data bus line BUS of the microcomputer, respectively.
21. The CPU 22 uses the above-mentioned input signals to execute calculations according to the program stored in the ROM 23 by accessing the RAM 24,
Based on the calculation result DPCNTL25.5TCNTL2
6 controls the display and shutter time, and PI0
A signal for controlling the lens is output to 27.

FIG. 4 28 shows a connector CNCT, which performs communication between the camera and the lens. 29 is a read-only memory LROM that stores information specific to the photographic lens; 30 is a focal position control mechanism AFCNTL of the photographic lens; and 31 is an aperture control mechanism APCNTL of the photographic lens.

LROM29 and AFCNTL included in the photographic lens
30°APCNTL31. It is connected to the camera's PIO 27 via the CNCT 28, and is configured to read out or operate the control mechanism according to instructions from the camera's CPU.

In this embodiment, as explained above, the photometric circuit AECK
T17, photometry mode selection switch AESW18, focus detection circuit AFCKT19, focus detection point selection switch AFS
Based on input signals from W20, a microcomputer is used to control the camera's display device, shutter, focus position adjustment of the photographic lens, and aperture.

Next, the operation of the first embodiment of the present invention will be explained with reference to FIGS. 5 to 8.

5 to 8 are flowcharts of the first embodiment of the present invention, with FIG. 5 showing the main routine and FIGS. 6 to 8 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 a plurality of preset focus detection points, information on metering mode selection based on the photographer's will,
and focus detection point selection information to control focus position adjustment, exposure control by shutter speed and aperture setting, and display control. There are other items that the main routine should handle, such as drive control of the quick return mirror and control of the film feeding mechanism, but only the items related to the photometry device of the camera of the present invention are extracted here, and a simple explanation will be given. Therefore, the others are omitted.

5TER'02: Retrieve defocus amount signals of three focus detection points from AFCKTI9. The amount of defocus is determined by a pair of line sensors, CCDL and CCDL2, CCDcl and CCD, corresponding to each focus detection point.
It is calculated by detecting the deviation of the output signals of c2, CCDR, and CCDR□, and is captured as a digital signal.

5TEPO3: Takes in the focus detection point selection signal from AFSW20 and the defocus amount signal from AFCKT19, and when the photographer selects one of the three focus detection points, that focus detection point is If the photographer automatically selects the focus detection point with 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 This is a focus detection point selection subroutine that outputs a signal corresponding to the 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 from AECKT17 as digital signals.

5TEPO6: This is a photometry mode selection subroutine that takes in the input signal from the AESW 18 and outputs a photometry mode signal MODE as a photometry mode according to the photographer's intention. In this example, the metering mode is set to be selectively determined by the photographer as either evaluative metering or partial metering. It is output as is as the signal MODE. Although different from this embodiment, if a photometry device is assumed in which the camera automatically determines the photometry mode, a signal corresponding to the photometry mode selected here will be output.

5TEPO7: The signal taken in from the AECKT17 is appropriately corrected based on the information specific to the photographic lens taken in from the L ROM 29, and the luminance signal of the object field corresponding to each small area is output. The above-mentioned focus detection point signal STL is generated using the luminance signal.

and a photometric value calculation subroutine that performs calculations determined based on the photometric mode signal MODE, and outputs a photometric value E.

5TEPO8: Determine the shutter speed and aperture value from the photometric value E based on a program preset in the camera, and output. Depending on the photographer's will, it may be possible to switch shooting modes such as shutter priority mode, aperture priority mode, etc. in addition to program mode. In either case, the shutter speed and aperture can be changed based on those programs. Determine the value.

5TEI] 09: Exposure information such as shutter speed and aperture value, as well as focus detection point selection information, photometry mode selection information, etc., as necessary, are displayed on the display device of the camera by the DPCNTL 25.

5TEPIO: Based on the shutter time and aperture value determined as described above, the 5TCNTL26 controls the shutter time, and the APCNTL31 controls the aperture of the photographing lens.

At 5TEPO2 to 5TEPIO, the camera completes a series of shooting operations, 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.

5TEPII: Focus detection point selection subroutine 5TEP
12: Take in the focus detection point selection information from the AFSW 20. The AFSW 20 outputs the focus detection point selection signal AUTO when the photographer sets the focus detection point to be automatically selected by the camera, and outputs the focus detection point selection signal AUTO when the photographer sets one focus detection point selectively. When the focus detection point SL located on the left side of the screen is selected, the focus detection point selection signal FL is output, and 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. However, if you select the focus detection point SR located on the right side of the shooting screen,
A focus detection point selection signal FR is output.

5TEP13-Determine whether the focus detection point selection signal is AUTO. 5TEP14 if AUTO
If the setting is not AUTO, proceed to 5TEP15.

5TEP14: When the focus detection point selection signal is AUTO, select three focus detection points SL and S 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). Note that when a plurality of focus detection points are equidistant and detected as being close, the signal FC of the central focus detection point Sc is output.

5TEP15: Depending on the focus detection point determined by the photographer's selection or automatic selection by the camera (11
, determine the point detection point signal SEL. The focus detection point signal SEL outputs one of FL, FC, and FR.

5TEP16: Return to the main routine.

FIG. 7 is a flowchart showing the 5TEPO6 photometry mode selection subroutine of FIG.

5TEP21: Photometry mode selection subroutine.

5TEP22: Load the photometry mode selection information from AESW18. AESW is a switch that allows the photographer to select either evaluative metering or partial metering; if evaluative metering is selected, output signal EV is output; if partial metering is selected, output signal PA is output. do.

5TEP23: AESW (7) output signal EV,
Alternatively, PA is directly output as the photometry mode signal MODE. In this embodiment, since the selection of the photometry mode is determined only by the will of the photographer, the photometry mode signal M
ODE outputs the input signal from the photometry mode selection switch AESW as it is.

5TEP24: Return to main routine.

FIG. 8 is a flowchart showing the 5TEPO7 photometric value calculation subroutine of FIG.

5TEP31: Photometric value calculation subroutine.

5TEP32: Digital signals Dog, D corresponding to the brightness of 15 small areas output from AECKT17
(12°D 03 , ..., take in B15.

Information unique to the attached photographic lens is taken in from the STE P 33/LROM 33. 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 information specific to the photographic lens, perform AE
Correction data δ01. which corrects each of the 15 output signals from the CKT. δoz, . . . , δ, 5 are determined, and a brightness signal for each small area is calculated. That is, the luminance signal V 0
1, V 02 , . . . V 15 are determined from the following formula and output. Note that the correction data δ01. δ02° . 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=FI4', proceed to 5TEP37 and 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. 5
EL=F (If 4', 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 P, 37, and when the focus detection point is at the center, 5TEP3
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 A, the average brightness signal of the area near the focus detection point, B1, the average brightness signal of the surrounding area, and C, 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 signals A, B,
C is output based on the following equation.

A = V 07 B = (Vo2+Vos+Voa+V12)/4C=
(Vo+10 vo3+VO4+Vos+Voc++V H
8+VI+ +”+3 +VI4 +V15) /10
STEP 38: Determine the classification of the middle area when the central focus detection point is selected, and calculate the average brightness signal of each middle area.
B and C are output based on the following equations.

A=Voa B: (VO3+VO7+VO9+V, 3)/4C=
(V01+V02+VO4+VO5+VO6+V
1G+v, 10v, 2+v, 4+v, 5)
/10 STEP 39: Determine the classification of the middle area when the right 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=VO9 B= (VD4+VQ8+V 10 +V 14 )
/4C= (V01+VQ2+VQ3+VO5+VO6
+VO7+V,, +V, □+V 13 + V +5)
/ 10 STEP 40: The photometry mode signal MODE is
It is determined whether the signal EV represents evaluation photometry. M.O.
If DE=EV, proceed to 5TEP41 and MODE≠
E.V.

That is, if MODE=PA, the process advances to 5TEP44.

5TEP41: Evaluative photometry is selected as the photometry mode, so calculation of evaluation photometry is performed. 5TEP37~5
Focus detection is performed using all of the average brightness signal A of the medium area near the focus detection point obtained in TEP39, the average brightness signal B of the medium area surrounding it, and the average brightness signal C of the medium area surrounding it. The average luminance signal E is used to weight approximately the entire screen, with a higher emphasis on the vicinity of the point. is calculated from the following formula.

E 0 = (A+B+C)/3 In the above formula, the three medium area brightness 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 (n
), and the area of the middle region around it is S (C)
Then, the area ratio of the three middle regions is 5(A):5(B
):5(C)=l:4:10, so by performing this calculation, the weighting of the vicinity of the focus detection point is increased (the average brightness is calculated. The importance of the three middle areas A, B, and C J (A), J (B), J (
C) is proportional to the reciprocal of the area ratio, J (A) : J (B) : J (C) = 1 : 0
．． 25:0.1. In the following explanation, E in the above equation will be used. The calculation for determining the value is called "one focus detection point weighted average photometry".

S T E l) 42・5TEP37-5TEP39
This is a correction value selection subroutine for estimating the shooting situation and selectively determining the exposure correction value α by using the average brightness signal of the middle region obtained in 1 and the difference between these average brightness signals. Details will be described later.

5TEP43: The above-mentioned focus detection point weighted average photometry E.

Then, 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.

The photometric value E obtained by E-Eo+α 5TEP41 to 5TEP43 is the photometric value obtained by evaluation photometry in this embodiment.

5TEP44: Metering mode signal is MOD at 5TEP40
When E≠EV, that is, when MODE=PA, partial photometry is selected as the photometry mode, so partial photometry calculations are performed. Partial metering is 5TEP37~5TEI'3
Of the average brightness signals in the middle area obtained in step 9, only the average brightness signal A in the middle area near the focus detection point is used, and this value is output as is as a photometric value E.

That is, E=A In this embodiment, as the medium area near the focus detection point, one light receiving small area including the focus detection point is selected in response to the selection of the focus detection point. Therefore, partial photometry becomes the luminance signal itself of this small area for light reception.

5TEP45: Return to the main routine.

As explained above, in the photometry value calculation subroutine, even when evaluation photometry is selected as the photometry mode,
Even when partial metering is selected, the emphasis on the metering area or the metering area itself is changed in conjunction with the selection of the focus detection point, making it possible to calculate appropriate metering values that accommodate the photographer's wishes. .

FIG. 9 is a flowchart showing the 5TEP42 correction value selection subroutine of FIG.

5TEP51: Correction value selection subroutine.

5TEP52: Using the average brightness signal A of the medium area near the focus detection point, the average brightness signal B of the medium area around it, and the average brightness signal C of the medium area around it, calculate the brightness signal of the adjacent medium area. Difference between A and B and B and C, ΔI3 A
and ΔCB are calculated from the following equation.

ΔI3i~2B-A ΔCB = C-B STEP 53: Convert the average brightness signal C of the surrounding medium area to a signal K corresponding to a predetermined brightness (here, identify whether it is an outdoor situation or an indoor situation) The approximate brightness of the subject is recognized by comparing the brightness of the subject. 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, 5 TEP
When C<K, that is, when it is determined that the situation is indoors, the process advances to 5TEP71.

5TEP54: When it is determined that the average brightness of the surrounding medium area is higher than a predetermined value and the scene is an outdoor scene, first, the brightness difference ΔBA is compared with a predetermined value PH1 having a positive sign.

ΔBA<P. If it is 1, proceed to 5TEP55 and ΔBA≧
If PH1, proceed to 5TEP56.

5TEP55 If △BA<P+++, further ΔB
A is compared with a predetermined value PH□ having a negative sign. ΔBA〈
If PH2, proceed to 5TEP60, ΔBA≧P)+2
In the case of PH2≦ΔBA<PH, STE
Proceed to P58.

5TEP54.5TEP55, the luminance difference ΔBA is classified into the following three types.

PH1≦ΔBA; ΔBA is a positive value with a large absolute value; PH2≦ΔBA<PH,; ΔBA is a small absolute value.

ΔBA<I)H2; ΔBA is a negative value with a large absolute value.

5TEP56: If P H, ≦ΔBA, further Δ
CB is compared with a predetermined value Q)I+ having a positive sign. ΔC
If B<Q, □, proceed to 5TEP57 and ΔCB≧QH
If I, proceed to 5TEP62.

If 5TEP57・ΔCB<QHL, add 8 CB
is compared with a predetermined value QH2 having a negative sign. ΔCB〈Q
In the case of H2, proceed to 5TEP64, and in the case of ΔCB≧QH2, that is, Q, A. 5TEP if ≦ΔCB<QHL
Proceed to 63.

5TEP56.5TEP57, the luminance difference ΔCB is classified into the following three types.

QHI　≦ΔCB; ΔCB is a positive value with a large absolute value QH2≦ΔCB<QHI; ΔCB has a small absolute value.

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

5TEP58: If PH2≦ΔBA<PH, ΔCB is further compared with a predetermined value QHI having a positive sign.

If ΔCB<QHl, proceed to 5TEP65 and ΔcB≧
In case of QHI, proceed to 5TEP59.

5TEP59: If ΔCB<QH, (7), further i,
Compare mΔcB with a predetermined value QH2 having a negative sign. Δ
If CB<Q H2, proceed to 5TEP67, ΔCB≧
In the case of QH2, that is, in the case of QH2≦ΔCB<QH□, the process advances to 5TEP66.

5TEP58.5TEP591. :The brightness difference ΔCB
are classified into the same three ways as in 5TEP56.5TEP57.

5TEP60: If ΔBA<PH□, ΔCB is further compared with a predetermined value QHI having a positive sign. ΔCB<Q
If H+, proceed to 5TEP68; if ΔCB≧Q)I+, proceed to 5TEP61.

5TEP61: If ΔCB<QHl, further ΔC
B is compared with a predetermined value QH2 having a negative sign. ΔCB<
If QH□, proceed to 5TEP70 and ΔCB≧QH
In the case of □, that is, in the case of Q)l□≦ΔCB<Q)11, the process proceeds to 5TEP69.

By 5TEP60.5TEP61, the brightness difference ΔCB is
It is classified into the same three ways as in 5TEP56.5TEP57.

When 5TEP53 determines that it is an outdoor scene, S T E P 5.4 to 5T as explained above.
By EP61, the situation of the photographic scene is classified into nine types, and the exposure correction value α is selected.

5TEP62~5TEP70: 5TEP54~5T
Exposure correction values α suitable for the scene conditions classified by EP61 are output. In this example, the value of α is α
, 7, α8□, and O (however, α) + 1 × α82 < 0), and any one of these three values is selected. A method for determining the exposure correction value α will be described later.

5TEP71: 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 luminance difference ΔBA is compared with a predetermined value PLI having a positive sign. If ΔBA<PL, proceed to 5TEP72 and set ΔBA
If ≧PLI, proceed to 5TEP73.

5TEP72: If ΔBA<PL, further increase ΔBA
is compared with a predetermined value PL2 having a negative sign. ΔBA<P
If L2, proceed to 5TEP77; if ΔBA≧PL2, that is, PL2≦ΔBA<PL, proceed to 5TEP7
Proceed to step 5.

5TEP71.5TEP72, the luminance difference ΔBA is 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 < PL 2; ΔBA is a negative value with a large absolute value.

5TEP73: If P L, ≦ΔBA, further ΔCB
is compared with a predetermined value QLI having a positive sign. ΔCB<Q
If Ll, proceed to 5TEP74, ΔcB≧QL1
If so, proceed to 5TEP79.

5TEP74: If ΔCB<Qt, +”, further ΔC
B is compared with a predetermined value QL□ having a negative sign. ΔcB<
If Q, 2, proceed to 5TEP81 and ΔCB≧QL2
In the case of QL2≦ΔCB<QLI, 5TE
Proceed to P80.

5TEP73.5TEP74i,: Brightness difference ΔCB
are classified into the following three types.

Q3. , ≦ to CB; ΔCB is a positive value with a large absolute value.

QL2≦△CB<QLI; △CB has a small absolute value.

ΔCB<QL2: ΔCB is a negative value with a large absolute value.

5TEP75: If P L2≦ΔBA<PLI,
Further, Δ(Jl is compared with a predetermined value QLI having a positive sign.

If ΔCB<QLI, proceed to 5TEP76, 8CB≧
In the case of QL+, proceed to 5TEP82.

5TEP76: If ΔCB<QLI, further ΔCB
is compared with a predetermined value QL2 having a negative sign. 8CB<Q
If L2, proceed to 5TEP84; if ΔCB≧QL2, that is, if QL2≦ΔCB<QLI, proceed to 5TEP
Proceed to 83.

With 5TEP75.5TEP76, the brightness difference ΔCB is
It is classified into the same three ways as in 5TEP73.5TEP74.

5TEP77: If ΔBA<PL2, ΔCB is further compared with a predetermined value QLI having a positive sign. ΔCB<Q
If Ll, proceed to 5TEP78; if ΔCB≧QL+, proceed to 5TEP85.

5TEP78: If ΔCB<QL□, further 8C
B is compared with a predetermined value QL2 having a negative sign.

If ΔCB<Q L2, proceed to 5TEP87 and set ΔCB
If ≧QL2, that is, if QL2≦ΔCB<QLI, the process advances to 5TEP86.

5TEP77.5TEP78, the brightness difference ΔCB is
It is classified into the same three ways as in 5TEP73 and 5TEP74.

STEP 5: When it is determined that the scene is an indoor scene at 3, 5TEP71-5 as explained above.
TEP78 classifies the situation of the photographic scene into nine types and selects the exposure correction value α.

S T E P 79~5TEP87:5TEP71~
Exposure correction values α suitable for the scene conditions classified by the 5TEP78 are output. In this embodiment, there are only three values of α: α03, αL2, and O (however, αL1
<0 × αL2), and one of these three values is selected. A method for determining the exposure correction value α will be described later.

5TEP88: Return to photometric value calculation subroutine.

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

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

5TEP62 to 5TEP70 and 5TEP7 in Figure 9
The 18 states classified into 9-5TEP87 are expressed as ΔB
A.

When ΔCB is expressed in a coordinate plane with the two seat tower axes, it becomes as shown in Figures 10 (a) and (b). Also, 5T in Figure 9
EP62-5TEP70, and 5TEP79-5TEP
The state of 87 is as shown in FIGS. 11(a) and 11(b) when the luminance signals A, B, and C of each middle region are shown in bar graphs. FIG. 11 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. 10 and 11.

(a) When K≦C: Outdoor scene (a-i) PH
1 < ΔBA, QHI × ΔCB (STEP 62) As shown in Figure 1O (a), ΔBA is a positive predetermined value P
) 11 and ΔCB is larger than a positive predetermined value QH+, and the luminance distribution is as shown in (i) of FIG. 11(a). In such a case, the background part has high brightness and the main subject part has relatively low brightness, so it can be estimated that the scene is a backlit scene of boat fishing. 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 E. The output will be as shown in the figure, but in order to give an appropriate exposure by fully considering the brightness of the main subject mentioned above and also taking into account the brightness of the background to some extent, it is necessary to use a relatively absolute value with a negative sign. Using the larger correction value αH1, (i) in FIG. 11(a)
It is preferable to output the evaluation photometric value E as shown in FIG.

(a-ii) PHI<ΔBA1Q)12<ΔCB≦
Q) It (STEP 63) As shown in FIG. 10(a), ΔBA is a positive predetermined value P.
H1, 8CB is larger than the negative predetermined value QH2, and smaller than the positive predetermined value Q)11, and as shown in FIG.
This is a case of a luminance distribution as shown in (ii) of a). 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, the size of the main subject in such a case may be approximately the same size as the area that outputs the brightness signal A, or it may be slightly smaller than this area, and in the former case, the brightness difference ΔBA is In the latter case, the luminance signal A itself has already been influenced by the background luminance, and the luminance difference ΔBA tends to be relatively small.In either case, the luminance difference ΔBA If it is detected that a main subject with relatively low brightness is located near the focus-detection point and is larger than the positive predetermined value PH1, the focus detection point weighted average photometric value E as shown in the figure is set. Then, while fully considering the brightness of the main subject and also taking into account the brightness of the background, the correction value α9 for the case (i) and the road gap etc.
．． It is preferable to output the evaluation photometric value E using .

(a-iji) P H, <ΔBA, ΔCB≦QH2
(STEP 64) As shown in Figure 10 Ca), 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 (jji) in FIG. 11(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. 11(a), using the correction value αH2 with a negative sign and a relatively small absolute value,
It is preferable to output the evaluation photometric value E.

(1-iv) PH2<ΔBA≦PH1, QHI<
ΔCB (STEP 65) As shown in Figure 1O (a), ΔBA is a negative predetermined value P.
Greater than H2 and smaller than the positive predetermined value PH1, ΔC
In the case where B is larger than the positive predetermined value Q, 41, FIG.
This is a case of a brightness distribution as shown in (iv) of a). In such a case as well, it can be estimated that the scene is a backlit scene, as in case (i). If we pay attention to the variation in the luminance signal,
Brightness signal A and brightness signal B are lower in brightness than brightness signal C, and the main subject is placed over a fairly wide area, including the area where brightness signal A is output and the area where brightness signal B is output. It is thought that this has been done. 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≦P) 13, QH□<ΔCB
≦QHI (STEP 66) As shown in FIG. 10(a), ΔBA is a negative predetermined value P.
Greater than H2 and smaller than the positive predetermined value P□1, Δ
CB is larger than the negative predetermined value QH2 and is a positive predetermined value Q
This is a case where the brightness difference is smaller than H1, and the brightness difference is small as shown in (V) of FIG. 11(a).

Such a brightness distribution occurs in the case of a backlit scene similar to case (ii) in which the size of the main subject becomes even smaller and it becomes difficult to detect the brightness of the main subject, and in case of (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, so set the correction value to O to give the entire screen an appropriate exposure.
Focus detection point weighted average photometric value E. Evaluate the photometric value E as it is
It is better to output it as

(a-vi) PH2<ΔBA≦PH1, ΔCB≦Q
l (2 (STEP 67)) As shown in Figure 1O (a), ΔBA is a negative predetermined value P.
)+2 and smaller than a positive predetermined value PH1, Δ
This is the case where CB is smaller than the negative predetermined value Q)+2, and the brightness distribution is as shown in (vi) of FIG. 1I(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, the correction value αH for the case of (city) and the area between roads etc. should be adjusted to depict the main subject part as whitish to some extent.
2 to output the evaluation photometric value E.

(a-vii) ΔBA≦PH2, QHI ΔC
B (STEP 68) As shown in FIG. 10(a), ΔBA is a negative predetermined value P.
This is a case where ΔCB is smaller than H□ and larger than a positive predetermined value QH+, and the brightness distribution is as shown in (vii) of FIG. 11(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 occur very rarely. 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 0.
, focus detection point weighted average photometric value E. It is better to output the evaluation photometric value E as it is.

(a-viii) ΔBA≦PH2, QH□kuΔ
CB≦QHI (STEP 69) As shown in Figure 1O (a), ΔBA is a negative predetermined value P.
This is a case where ΔCB is smaller than H2, larger than a negative predetermined value Q)+2, and smaller than a positive predetermined value QH□, and the luminance distribution is as shown in (viii) of FIG. 11(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 O.

(a-ix) ΔBA≦PH2, 8CB≦Q)+
2 (STEP 70) As shown in FIG. 10(a), ΔBA is a negative predetermined value P.
This is the case where ΔCB is smaller than the negative predetermined value Q8°, and the brightness distribution is as shown in (ix) in FIG. 11(a). In such a case, (vi) It is estimated that the object is the same as in case (vi) and (viii), and the size of the main object can be judged to be intermediate between cases (vi) and (viii). Compared to cases vi) and (viii), the area near the focus detection point has even higher brightness, and it can be determined that there is an object with a higher reflectance, or that some kind of light source is placed. In such a case, even if you use the focus detection point weighted average photometric value E as shown in the figure, the main subject will be depicted as whitish to some extent. In order to depict the part more whitish, (iii)
It is preferable to output the evaluation photometric value E by using the correction value α8□ for the road distance, etc.

(b) Scene in two rooms when C<K (b-i) PL, <ΔBA, QL, <ΔCB (STEP
79) As shown in FIG. 10(b), ΔBA is a positive predetermined value PL.
This is a case where ΔCB is larger than a positive predetermined value QLI, and the luminance distribution is as shown in (i) of FIG. 11(b). In such a case, the background part is In addition to not having high brightness, the brightness of the main subject part is considerably lower than the background part, so scenes where the main subject is placed in a position that is not illuminated by indoor lighting can be assumed. It is also assumed that there is a scene in which an object with a slightly low reflectance (darkish) is placed near the detection point.Also, the size of the main object is similar to the area that outputs the brightness signal A as in (a-i). It is thought that the area exists over a part of the area where the luminance signal (b) is output.

Under such conditions, in order to depict the situation of the subject observed by the photographer in a way that matches the photographer's senses, the main subject should be slightly blackened to the extent that its details are not reproduced. It is desirable to give the exposure as depicted.

Therefore, as shown in (i) of FIG. 11(b), the focus detection point weighted average photometric value E. In contrast, it is preferable to obtain the evaluation photometric value E using a correction value αL1 having a negative sign and a relatively small absolute value.

(b ii) PLI< ΔBA, Q L2 <
ΔCB≦QLI (STEP 80) As shown in FIG. 11(b), ΔBA is a positive predetermined value P.
If ΔCB is larger than the negative predetermined value QL2 and smaller than the positive predetermined value QLI, then
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, it can be determined that the size of the main subject is slightly smaller than in case (i), similar to case (a-ii). Even in this case, as in case (i), the main subject can be slightly darkened (
It is desirable to depict (
In the case of i), the correction value α1 for the road gap, etc. It is preferable to output the evaluation photometric value E using .

(b-city) PLI<ΔBA, ΔCB≦QL2 (STEP
81) As shown in FIG. 11(b), ΔBA is a positive predetermined value P.
This is a case where ΔCB is larger than LI and smaller than a negative predetermined value QL2, and the luminance distribution is as shown in (iii) of FIG. 11(b). Such a brightness distribution appears when there is a locally high-brightness object such as an illumination light source in the area where the brightness signal B is output. In such a case, the focus detection point weighted average photometric value E. In order to give a suitable exposure for such a scene where the main subject part is depicted as somewhat dark due to the influence of this high brightness area, the correction value is set to 0 and the focus detection point weighted average is set as shown in the figure. Photometric value E. It is better to output the evaluation photometric value E as it is.

(b-iv) PL2<ΔBA≦PL1, QLIkuΔ
CB' (STEP 82) As shown in FIG. 10(b), ΔBA is a negative predetermined value PL.
2 and smaller than a positive predetermined value PLI, Δ
In the case where CB is larger than the positive predetermined value QLI, Fig. 11 (
This is a case of a brightness distribution as shown in (iv) of b). In such a case, as in case (1), 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 the main subject is arranged over a fairly wide area of the photographic screen. Even in such cases,
As in case (i), it is desirable to render the main subject part a little blackish, but as shown in the figure, the focus detection point weighted average photometric value E0 is a value that gives a fairly suitable exposure even as it is. Therefore, the correction value is set to O, and the focus detection point weighted average photometric value is E. It is better to output it as is as an evaluation photometric value.

(b V) PL2<ΔBA≦PLI, QL2<Δ
CB≦QL2 (STEP 83) 7 As shown in FIG. 10 (C), ΔBA is larger than the negative predetermined value PL2 and smaller than the positive predetermined value PLI,
This is a case where ΔCB is larger than the negative predetermined value QL2 and smaller than the positive predetermined value QLI, and the brightness difference is small as shown in (V) of FIG. 11(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 few scenes where the brightness difference is small (there are few). In such a case, set the correction value to O to give the appropriate exposure to the entire screen as in (a-v), It is preferable to output the focus detection point weighted average photometric value E as it is as the evaluation photometric value E.

(b-vi) PL2<ΔBA≦PLI, ΔCB≦Q
L2 (STEP 84) As shown in FIG. 1O (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 that outputs the brightness signal A and the area that outputs the brightness signal B, and the main subject is illuminated by the illumination light, and the other back areas This is the case when the brightness is relatively high compared to the above. 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, QL+ <Δ
CB (STEP 85) As shown in FIG. 10(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 Q L 1, and the brightness distribution is as shown in (vii) of FIG. 11(b). As in (a-vii), this kind of brightness distribution appears under special circumstances, and in this case, as in (a-vii), it is necessary to give appropriate exposure to the entire screen. Therefore, by setting the correction value to 0, the focus detection point weighted average photometric value E is obtained. It is better to output the evaluation photometric value E as it is.

(t) -viii) ΔBA≦PL2, QL2<
ΔCB≦QLI (STEP 86) As shown in FIG. 10(b), ΔBA is a negative predetermined value P.
This is a case where 8CB is larger than the negative predetermined value QL2 and smaller than the positive predetermined value QL+, and the brightness distribution is as shown in (viii) of FIG. 11(b). In such a case, as in case (vi),
It can be estimated that the scene is such that only the main subject part has relatively high brightness due to illumination light or the like. Further, 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, the focus detection point weighted average photometric value E is used as shown in the figure. In contrast, it is preferable to output the evaluation photometric value E using the case (vi) and the correction value αL2 for the road gap, etc.

(b-ix) ΔBA≦PL2, ΔCB≦Q
L2 (STEP 87) As shown in FIG. 1O (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. 11(b). In this case, it is presumed that the subject is the same as in case (vi), and the size of the main subject is judged to be about the size of mj between cases (vi) and (viii). can. Also, in this case, compared to cases (vl) 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, the area near the focus detection point is rendered a little whitish, giving emphasis to the main subject and giving an exposure that takes into account the balance of the entire screen, as shown in (vi). 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<αH2<0 αL, <0<αL2 Also, tlH+ or αH2 and α5. Regarding the magnitude relationship of , the predetermined value PH1l PH21QH
t, lr PL 21 Q L + r Q L
Although it differs depending on the setting of 2, when compared when the brightness differences ΔBA and ΔCB are values such as between roads, it is generally desirable to set α82<αLl.

In the method for determining the exposure correction value α explained above, to simplify the explanation, the scene was classified in nine ways based on the brightness difference ΔBA and ΔCB.
Especially in situations where the selection result of the exposure compensation value α changes greatly depending on the brightness difference, such as the classification of the states in b) and (ii) and the state in (V), more detailed classification is necessary. 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. Classifying the scene more closely in this way makes it possible to reduce exposure unevenness 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. 12(a) and (b), respectively. ).

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

[Other Examples]

FIGS. 13(a) and 13(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. 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 13(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. 13, 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 manner 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 the field into a plurality of small areas so that the brightness of each small area can be detected, and also has a plurality of focus detection areas, and one of the focus detection areas When performing partial metering on a camera that allows selection of the focus detection area, the brightness information of the selected small area including the focus detection area is automatically used as the metering value, making accurate metering of the main subject easy and convenient. We can provide a camera that can do this.

[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. 10 to 12 are explanatory diagrams for explaining the flowchart of the first embodiment of the present invention. FIG. 13 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// tz S/, 3 Sη ACB (ν11 (57F/', ni 43) (iy ) (5TEPl-3) (1n (STEP, &) (Viii) (STEP Otsu9) (V) (SrEP<6) (ii) (STEf%3) tir) C3rEP70) (Vl) (S″rEPzri ) Crii) (57E/' 1st/Figure (b) +l'I (νii) (, P85) (W) (STEI"21+2) (11C3TEP7ri) (Viii) C3TEP7%) CV) (5TTEFB3) to υ (51P cry(ix) (swr87) (VI) C3TEP7.) to 1θ <5TEP8/ )

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 a light receiving means for detecting brightness; a first light metering mode that uses brightness information of a portion of the photographic screen as a light metering value;
a second photometry mode that calculates a photometry value by various calculations based on luminance information of the entire photographic screen; a detection area selection unit that selects one of a plurality of focus detection areas; and the photometry The mode selection means further includes a control means for using, as a photometric value, luminance information of the small area including the focus detection area selected by the detection area selection means when the first photometry mode is selected. Featured camera.