JPH0727151B2 - camera - Google Patents

Description

TECHNICAL FIELD The present invention relates to a camera that divides a photometric range into a plurality of small areas for photometry.

[Conventional technology]

Conventionally, various photometric devices have been proposed in which the object scene is divided into a plurality of areas, a luminance signal for each area is output, and the plurality of luminance signals are used to provide proper exposure to a shooting screen. ing.

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

Further, in Japanese Examined Patent Publication No. 63-7330, the object field is divided into a central region and a plurality of outer regions which are arranged so as to surround the central region, and photometry is performed. With the reference value set between the maximum and minimum values of the brightness of the area, the brightness of each area is standardized, the field is classified based on this standardized output, and the photometric value is We have proposed a photometric device for calculation.

In the above conventional example, there was little consideration on the placement of the main subject in the shooting screen, but it is assumed that the main subject is placed in a camera or the like equipped with an automatic focus detection device, and the placement of the main subject in the shooting screen is greatly considered. Is also proposed.

For example, in Japanese Unexamined Patent Publication No. 61-279829, the center of the screen is set as the position where the main subject is arranged, and the object scene is divided into a plurality of regions including a plurality of concentric regions centered at least on the center of the screen. Proposing a photometric device capable of accurately obtaining the luminance of the main subject by selectively using the luminance signal of the concentric area assuming the size of the main subject based on the information of the photographing magnification. There is. Further, in the publication,
In addition to the brightness of the main subject, the brightness of the background is also calculated, and we are proposing a change in the photometric value calculation command that uses these brightness differences.
Not only is it possible to give an appropriate exposure to the main subject, but it is also possible to give an appropriate exposure suitable for the shooting situation when the main subject is small.

Also in JP-A-62-184319, the center of the screen is set as a position where the main subject is easily arranged, and the field of view is defined as a region in the center of the screen, a region outside thereof, and a region outside thereof. , Is divided into at least three areas, and the approximate size of the main subject and the shooting condition are simultaneously determined based on the difference between the brightness signals of the plurality of areas and the brightness signals of the adjacent areas to determine an appropriate value. I am proposing a photometric device that gives exposure. In this publication, since the approximate size of the main subject is determined by using the difference in the luminance signal, it depends on the actual size of the main subject as compared with the one in which the size of the main subject is estimated using the shooting magnification. There is an advantage that it is difficult to do so, and it becomes possible to stably obtain an appropriate exposure.

In the two conventional examples cited here, the reason why the center part of the screen is assumed to be the position where the main subject is easily arranged is that the focus detection area of the camera equipped with the automatic focus detection device is generally set in the center part of the screen. Is. On the other hand, recent automatic focus detection devices have been proposed that have a plurality of focus detection regions, and in a camera equipped with such an automatic focus detection device, each of the multiple focus detection devices has a It is easy for the main subject to be placed in a specific area other than the central portion.

Although various photometric devices have been proposed in which the field of view is divided into a plurality of regions and the photometric value is calculated by various calculations in this manner, a device that accurately determines whether or not to perform flash emission is relatively proposed. Few. As a device for detecting only the backlit state, for example, Japanese Patent Application Laid-Open No. 1-280737 proposes a device for detecting the backlit state based on a difference in luminance between predetermined regions.

[Problems to be Solved by the Invention]

In a conventional multi-divisional photometric camera, the backlight can be easily determined by comparing the brightness of the central area and the peripheral area, but the low brightness can be determined by other detection, for example, the value of average photometry as a reference value. A method of comparison is needed.

[Means for Solving the Problems]

The present invention is a camera including a focus detection unit configured to be able to independently detect focus in a plurality of areas within a photographic screen, divides a photometric range into a plurality of photometric areas, and detects the brightness of each of the divided photometric areas. Light receiving means, first brightness information of a photometry area including a focus detection area selected from the plurality of focus detection areas, and second brightness information indicating a maximum value in the plurality of photometry areas. Judgment for judging the necessity of flash light emission by comparing the brightness comparison means for comparing and the comparison information corresponding to the difference obtained by the comparison means with a predetermined value that changes depending on the value of the first brightness information. And a camera having means.

〔Example〕

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

FIG. 1 is a diagram showing a divided shape of a light receiving surface of a light receiving portion for photometry according to the first embodiment of the present invention, showing a state of being projected on a field. In the figure, S ₀₁ , S _02, ..., S ₁₅ represent a plurality of divided small light-receiving regions, and S _L , S _C , and S _R are focal points projected on the field like the light-receiving unit for photometry. It represents the detection field of view.
In the present embodiment, as shown in FIG. 1, the field is divided into three small areas including three focus detection points and 12 small areas surrounding the small area, for a total of 15 small areas. The brightness of the field is measured for each small area.

FIG. 2 is a view showing the optical arrangement of the first embodiment of the present invention,
In the figure, 1 is a taking lens, 2 is a quick return mirror, 3 is a focusing plate, 4 is a penta roof prism, 5 is an image forming lens for photometry, 6 is a light receiving part for photometry, 7 is an eyepiece lens,
8 is a pupil position, 9 is a sub-mirror, 10 is a field mask, 11 is a condenser lens, 12 is a total reflection mirror, 13 is a pupil division mask, 14
Is an image forming lens for focus detection, 15 is a focus detection light receiving portion, and 16 is a film surface. In this embodiment, the taking lens 1
The subject image formed on the focusing plate 3 is formed on the photometric light receiving portion 6 by the photometric imaging lens 5 and divided into the 15 small regions shown in FIG. 1 to perform photometry. Also, a part of the subject image formed near the visual field mask 10 arranged near the planned image forming surface of the photographing lens 1 is used as a focus detecting image forming lens.
An image is formed on the focus detection light receiving unit 15 by the focus detection unit 14 to detect the focus of a region corresponding to the three focus detection fields shown in FIG. FLA indicates a built-in flash device.

FIG. 3 is an exploded perspective view of the focus detection optical system shown in FIG. 2. As shown in FIG. 3, three openings are provided in the field mask 10 arranged near the planned image forming surface of the taking lens 1. This 3
The subject image formed in the vicinity of one opening is divided into two images by the focus detection imaging lens 14 and focused on the focus detection light receiving portion 15 to detect the focus of three points in the photographing screen. Is going.

FIG. 4 is a block diagram showing the circuit configuration of the first embodiment of the present invention. In the figure, SPD ₀₁ , SPD ₀₂ ..., SPD ₁₅ are the 15 light-receiving small areas S ₀₁ , S ₀₂ ..., SPD ₁₅ shown in FIG. 1, respectively.
It is a silicon photodiode (SPD) corresponding to S ₁₅ , and generates a photocurrent according to the brightness of each small area. AMP ₀₁ , AMP ₀₂ ..., AMP ₁₅ and DI ₀₁ , DI ₀₂ , ..., D
I ₁₅ is an operational amplifier and a compression diode, respectively, and a silicon photodiode (SPD) and an operational amplifier and a compression diode are combined to form a light receiving means corresponding to the 15 light receiving small regions in FIG. . Fig. 4-17
Is a photometric circuit AECKT, which A / D-converts the output signals corresponding to the luminances of the plurality of light-receiving small areas, and outputs them as digital signals. Reference numeral 18 is a flash mode selection switch FLSW, and a forced light emission mode in which the flash (built-in flash FLA) is forcibly turned on by the operator's intention,
Depending on the situation of the scene, the camera automatically detects whether or not flash photography should be performed, and automatically detects the flash or recommends the use of flash, and the flash is forced by the operator. It is possible to select one of the forced non-emission modes that are turned off. 15 is a focus detection light receiving unit corresponding to Figure 3, CCD _L1 and CCD
_L2 , CCD _C1 and CCD _C2 , and CCD _R1 and CCD _R2 are three pairs of light receiving element arrays corresponding to the focus detection fields S _L , S _C , and S _R of FIG. 1, respectively. In the pair of light receiving element rows, among the field lights that are imaged in a predetermined area of the photographic screen by the optical system shown in FIG. 2 and FIG. Only the light flux that has passed through the two regions is taken out to form an image, and the defocus amount can be detected by comparing the output signals from the pair of light receiving element arrays. Reference numeral 19 denotes a focus detection circuit AFCKT, which is based on the output signals from the three pairs of light receiving element arrays provided in the focus detection light receiving unit 15, and as described above, the three focus detection fields S _L , The defocus amount of the object field corresponding to S _C and S _R is detected, and the information of the three defocus amounts is output as a digital signal. 20 is a focus detection point selection switch
AFSW, which is automatically shot by the camera according to the operator's will according to the distribution state of the defocus amount in the field corresponding to the three focus detection fields S _L , S _C , and S _R in FIG. Between an automatic selection mode for determining a suitable focus position and an arbitrary selection mode for the operator to selectively determine any one of the three focus detection fields of view of FIG. And in optional mode,
The focus detection selection switch is configured to indicate a focus detection point to be selected. In FIG. 4, the photometric circuit AECKT17, flash mode selection switch FLSW18,
Focus detection circuit AFCKT19, focus detection point selection switch AFSW20
The input signal from is connected to the 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 CP for processing various input signals described above by using programs stored in various memories and instructing the operation of various control mechanisms.
U and 23 are read-only memory ROMs that store various programs, 24 is a random access memory RAM in a work area for computations, 25 is a display control mechanism DPCNTL, 26 is a shutter speed control mechanism STCNTL, and 27 is flash control. Mechanisms FLCNTL and 28 are general-purpose input / output ports PIO, and internal data bus line BUS21 of the microcomputer
It is connected to the. The CPU executes the operation according to the program stored in the ROM by accessing the RAM by using the above input signal, and based on the operation result, the DPCNTL
25, STCNTL26, FLCNTL27 perform display and control of shutter speed flash, and output a signal for lens control to PIO28.

Fig. 4 shows the connector CNCT, which communicates between the camera and the lens. 30 is a read-only memory LROM that stores information specific to the shooting lens, 31 is the focus position control mechanism AFCNTL of the shooting lens, 32 is the aperture control mechanism of the shooting lens
This is APCNTL. LROM30 and AFCN provided in the shooting lens
It is connected to PIO28 of the camera via TL31, APCNTL32, and CNCT29, and reads it according to the instruction of CPU22 of the camera.
Alternatively, the control mechanism is operated.

In this embodiment, as described above, the photometric circuit AECK
Based on the input signals from T17, flash mode selection switch FLSW18, focus detection circuit AFCKT19, focus detection point selection switch AFSW20, the camera's display device, shutter, flash, the focus position adjustment of the shooting lens using a micro-computer. Also, the aperture is controlled.

The software configuration of the first embodiment of the present invention will be described below.

5 to 11 are flow charts showing the software configuration of the first embodiment of the present invention, FIG. 5 shows a main routine, and FIGS. 6 to 11 show each subroutine.

First, the main routine of FIG. 5 will be described.

STEP01: Main routine In the camera, information corresponding to the brightness of the object field, information on the default focus amount of each of a plurality of preset focus detection points, flash mode selection information based on the will of the photographer, and focus detection Focus position control using point selection information and exposure control by shutter time and aperture setting,
Handles flash control and display control. There are other items to be handled by the main routine, such as the drive control of the quick return mirror and the control of the film feeding mechanism, but here only the items related to the photometric device and flash photography control device of the camera of the present invention will be described. Taking it out,
Others are omitted for simplicity.

STEP02: Capture the signals of the defocus amount of three focus detection points from AFCKT19. The defocus amount is a pair of line sensors corresponding to each focus detection point, CCD _L1 and CC
It is calculated by detecting the deviation amount of the output signal of D _L2 , CCD _C1 and CCD _C2 , and CCD _R1 and CCD _R2 , and is captured as a digital signal.

SREP03: Focus detection point selection signal from AFSW20 and AFCKT19
The signal of the amount of differential orcus from
When one focus detection point is selected from the two focus detection points, a signal corresponding to the focus detection point is output, and when the photographer selects the focus detection point automatically by the camera,
This is a focus detection point selection subroutine that detects a focus detection point having the closest object distance from the signals of the three defocus amounts and outputs a signal corresponding to the focus detection point, and outputs a focus detection point signal SEL.

STEP 04: The defocus amount for the focus adjustment is determined from the signals of the defocus amounts of the three focus detection points and the above-mentioned focus detection point signal SEL, and the AFCNTL 30 adjusts the focus of the photographing lens.

STEP05: From AECKT17, a signal corresponding to the brightness of 15 small areas and a digital signal are fetched.

STEP06: Corrects the signal captured from AECKT17 based on the information specific to the taking lens captured from DROM29, and outputs the luminance signal of the field corresponding to each small area. Based on the focus detection point signal SEL described above, the brightness signal A of the middle area including the focus detection point, the brightness signal B of the middle area around it, and the brightness signal C of the middle area around it Is a subroutine for calculating the maximum value MAX of the brightness signals of 15 small areas, and outputs the above-mentioned four brightness signals A, B, C, MAX.

STEP07: A signal that captures the input signal from FLSW18 and judges whether or not flash photography should be performed, depending on the will of the photographer or the field situation of the camera, and indicates whether or not flash photography should be performed.
This is a flash photography setting subroutine that outputs FLSH. The method of determining the field situation by the camera will be described later.

STEP08: This is a photometric value calculation subroutine for inputting the brightness signals A, B, C and the output signal FLSH of the flash photography setting subroutine and outputting the photometric value E during natural light photography and during flash photography.

STEP09: Based on the program preset in the camera, determine the shutter time and aperture value from the photometric value E, and depending on the photographer's will to output, in addition to the program mode,
The shooting modes such as the shutter priority mode and the aperture priority mode may be switched. In any case, the shutter speed and the aperture value are determined based on these programs.

Step 10: The exposure information of the shutter speed and aperture value, and the focus detection point selection information, the photometry mode selection information, the flash usage recommendation information and the like are displayed on the camera display device by the DPCNTL25.

STEP11: Based on the shutter time determined as described above and the aperture value, STCNTL26 controls the shutter time, APCNTL controls the aperture of the taking lens, and
The FLASHL FLA is controlled by FLCNTL.

In the above STEP02 to STEP11, a series of shooting operations in the camera is ended, and the state returns to STEP02 to prepare for the next shooting operation.

Next, each subroutine will be described.

FIG. 6 is a flow chart showing the STEP03 focus detection point selection subroutine of FIG.

STEP21: Focus detection point selection subroutine STEP22: Import focus detection point selection information from AFSW20. AFS
W, when the photographer sets the focus detection point to be automatically selected by the camera, outputs the focus detection point selection signal AUTO,
When the photographer selectively sets one focus detection point, when the focus detection point S _L located on the left side of the shooting screen is selected, the focus detection point selection signal FL is output and the focus detection point is positioned at the center of the shooting screen. When the focus detection point S _C is selected, the focus detection point selection signal FC is output, and when the focus detection point S _R located on the right side of the photographing screen is selected, the focus detection point selection signal FR is output.

STEP 23: Determine whether the focus detection point selection signal is AUTO. If it is AUTO, proceed to STEP 24. If it is not AUTO, proceed to STEP 25.

STEP24: When the focus detection point selection signal is AUTO, AFCKT19
From the three focus detection points S _L , S _C , and S _R , the focus detection point with the shortest subject distance is identified using the signal of the defocus amount output from the signal, and the signal corresponding to the focus detection point is identified. Outputs Nearest (FL, FC, FR).

Step 25: The focus detection point signal SEL is determined according to the focus detection point determined by the photographer's selection or the camera's automatic selection. The focus detection point signal SEL outputs any one of FL, FC and FR.

STEP26: Return to the main routine.

FIG. 7 is a flow chart showing the STEP06 area luminance calculation subroutine of FIG.

STEP31: Photometric value calculation subroutine.

Step 32: Capture the digital signals D ₀₁ , D ₀₂ , D ₀₃ , ..., D ₁₅ corresponding to the brightness of 15 small areas output from AECKT17.

STEP33: Import the information specific to the attached shooting lens from LROM33. The information unique to the taking lens includes the open F number of the taking lens, the focal length, the position of the exit pupil, and the information on the amount of peripheral light drop when the diaphragm is opened.

STEP34: 15 from AECKT using information specific to the shooting lens
Correction data δ ₀₁ for correcting each output signal,
δ ₀₂ , ..., δ ₁₅ are determined, and the luminance signal for each small area is calculated. That is, the brightness signals V ₀₁ , V ₀₂ , ..., V ₁₅ are obtained from the following equation V ₀₁ = D ₀₁ + δ ₀₁ V ₀₂ = D ₀₂ + δ ₀₂ :: V ₁₅ = D ₁₅ + δ ₁₅ and output. The correction data δ ₀₁ , δ ₀₂ , ...,
It is assumed that δ ₁₅ is selected and determined from a table stored in advance in the ROM 23 based on the above-mentioned information specific to the taking lens. It is also possible to calculate by calculation.

STEP 35: It is determined whether the focus detection point signal SEL is the signal FL representing the focus detection point on the left side of the shooting screen. If SEL = FL, proceed to STEP37. If SEL ≠ FL, proceed to STEP36.

Step 36: It is judged whether or not the focus detection point signal SEL is the signal FC representing the focus detection point at the center of the shooting screen. If SEL = FC, proceed to STEP38. If SEL ≠ FC, proceed to STEP39.

According to STEP35 and STEP36, classification is performed according to the focus detection point.If the focus detection point is on the left side, proceed to STEP37.If the focus detection point is in the center, proceed to STEP38, otherwise.
That is, when the focus detection point is on the right side, the process proceeds to STEP39.

STEP37 to STEP39 classify the 15 small areas into three middle areas, the area around the focus detection point, the area around it, and the surrounding area, and calculate the average brightness of each middle area. Then output. At this time, the 15 small areas are classified so as to be included in any one middle area. As the average brightness signal of each middle area, the average brightness signal of the area near the focus detection point is output as A, the average brightness signal of the surrounding area is B, and the average brightness signal of the surrounding peripheral area is output as C, respectively. .

Step 37: Determine the classification of the middle area when the left focus detection point is selected, and output the average luminance signals A, B, C of each middle area based on the following equation.

A = V ₀₇ B = (V ₀₂ + V ₀₆ + V ₀₈ + V ₁₂ ) / 4 C = (V ₀₁ + V ₀₃ + V ₀₄ + V ₀₅ + V ₀₉ + V ₁₀ + V ₁₁ + V ₁₃ + V ₁₄ + V ₁₅ ) /
10 STEP38: Determine the classification of the middle area when the central focus detection point is selected, and output the average luminance signals A, B, C of each middle area based on the following equation.

A = V ₀₈ B = (V ₀₃ + V ₀₇ + V ₀₉ + V ₁₃ ) / 4 C = (V ₀₁ + V ₀₂ + V ₀₄ + V ₀₅ + V ₀₆ + V ₁₀ + V ₁₁ + V ₁₂ + V ₁₄ + V ₁₅ ) /
10 STEP39: Determine the classification of the middle area when the right focus detection point is selected, and output the average luminance signals A, B, C of each middle area based on the following equation.

A = V ₀₉ B = (V ₀₄ + V ₀₈ + V ₁₀ + V ₁₄ ) / 4 C = (V ₀₁ + V ₀₂ + V ₀₃ + V ₀₅ + V ₀₆ + V ₀₇ + V ₁₁ + V ₁₂ + V ₁₃ + V ₁₅ ) /
10 STEP40: Maximum value M of luminance signal output from 15 small luminances
ax (V ₀₁ , V ₀₂ , V ₀₃ , ..., V ₁₅ ) is selectively determined and output as the maximum luminance signal MAX.

STEP 41: Return to the main routine.

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

FIG. 8 is a flow chart showing the flash photography setting subroutine of STEP07 of FIG.

STEP 51: Flash shooting setting subroutine.

STEP52: Get flash photography setting information from FLSW18. FLSW
Is set to output the flash photography setting signal ON when the photographer forcibly performs the flash photography, and the camera automatically determines whether or not the photographer should perform the flash photography. If so, the flash photography setting signal AUTO is output, and if the photographer forcibly sets not to perform flash photography, the flash photography setting signal OFF is output.

Step 53: If the flash photography setting signal is ON, proceed to STEP 55. In other cases, ie, if AUTO or OFF, proceed to STEP 54.

STEP54: If the flash photography setting signal is AUTO, STEP56
If not, that is, if it is OFF, go to STEP57.
Go to.

According to STEP53 and STEP54, the input signal from FLSW is categorized into three types: ON, AUTO, and OFF.

STEP55: When the input signal from FLSW is ON, the flash setting signal FLSH is output as FLON.

STEP56: This is a flash photography condition determination subroutine that determines whether or not flash photography should be performed according to the luminance distribution state of the field when the input signal from the FLSW is AUTO. In the flash photography condition determination subroutine, the area brightness signal A and the maximum brightness signal MAX of the brightness signals output from the area brightness calculation subroutine of STEP 06 in FIG. 5 are input, and predetermined condition determination is performed to perform flash photography. If it is judged that the flash setting signal FLSH is output as FLON,
When it is determined that flash photography should not be performed, the flash setting signal FLSH is output as FLOFF.

STEP57: When the input signal from FLSW is OFF, the flash setting signal FLSH is output as FLOFF.

According to STEP55 to STEP57, the flash setting signal FLSH is output as FLON when the flash shooting is to be performed, and the flash setting signal FLSH is output as FLOFF when the flash shooting is not to be performed.

STEP58: Return to the main routine.

FIG. 9 is a flow chart showing the STEP56 flash photography condition determination subroutine of FIG.

STEP 61: Flash photography condition determination subroutine.

STEP62: Of the output signals of the area brightness calculation subroutine of STEP06 in FIG. 5, the area brightness signal A and the maximum brightness signal MAX
Is inputted and the luminance difference signal DELTA thereof is calculated by the following equation.

DELTA = MAX-A STEP59: The brightness signal A in the middle area including the focus detection point is set to the predetermined brightness signal R _L set to the low brightness side (here, it is discriminated whether the situation is outdoors or indoors). The approximate luminance of the main subject is recognized. When A> R _L, that is, when it is determined that the outdoor situation proceeds to STEP 63, when the A ≦ R _L, that is, when it is determined that the indoor conditions proceeds to STEP66.

STEP63: The brightness signal A of the middle area including the focus detection point is set to a predetermined brightness signal R _H set to the higher brightness side (here,
The value is such that it distinguishes whether the main subject is placed outdoors in the shade or in the shade. ) In order to recognize the approximate brightness of the main subject placed outdoors in more detail. When A> R _H , that is, when it is determined that it is an outdoor sunlit situation, the process proceeds to STEP65, and when A ≦ R _H (hence R _L <A ≦ R _H ), that is, an outdoor shade If it is determined that the situation is, proceed to STEP64.

STEP 64: Compare the luminance difference signal DELTA with a first predetermined value r _L for determining whether or not there is a backlight condition. When DELTA <r _L , it is judged that it is not the backlight condition, and the process proceeds to STEP68, and DELT
When A ≧ r _L , it is determined that the backlight is on and the process proceeds to STEP 67.

STEP 65: Compare the luminance difference signal DELTA with a second predetermined value r _H for determining whether or not there is a backlight condition. When DELTA <r _H , it is determined that the backlight is not on, and the process proceeds to STEP70. DELT
When A ≧ r _H , it is determined that the backlight is on, and the process proceeds to STEP69.

According to STEP63 to STEP65, it is judged whether the situation of the main object scene is a low brightness situation or a backlight situation by classifying into the following five categories.

STEP66: In case of the above low brightness. It is determined that flash photography should be performed, and the flash setting signal FLSH is output as FLON.

Step 67: In the case of the above-mentioned slightly high brightness and backlight, it is determined that flash photography should be performed, and the flash setting signal FLSH is output as FLON.

STEP68: In the case of the above-mentioned slightly high brightness and normal light, it is determined that flash photography should not be performed, and the flash setting signal FLSH is output as FLOFF.

Step 69: In the case of the above-mentioned high brightness and backlight, it is determined that flash photography should be performed, and the flash setting signal FLSH is output as FLON.

Step 70: In the case of the above-described high brightness and normal light, it is determined that flash photography should not be performed, and the flash setting signal FLSH is output as FLOFF.

As described above, in STEP66 to STEP70, in STEP63 to STEP
The flash setting signal FLSH is determined and output by determining whether or not flash shooting should be performed according to the situation of the object field classified by 65.

STEP 71: Return to the flash shooting setting subroutine.

FIG. 12 shows the method of determining the flash photographing condition described above.
In FIG. 12, one coordinate axis is used as the brightness difference signal DELTA and the other is used as the area brightness signal A, and the distribution state of the brightness of the object scene is identified. As described above, in this embodiment, flash photography is performed in the shaded area of FIG. 12, and natural light photography is performed in the non-shaded area of FIG. A method of determining the shooting situation based on the figure will be described below.

(A) A ≦ _RL (STEP66) When the luminance signal A of the middle area including the focus detection point is smaller than the predetermined value _RL set on the low luminance side, and it is determined that the main subject is placed indoors. Is. In such a case, the illumination light that illuminates the subject is often light having a different color temperature from outdoor natural light such as a fluorescent lamp. When natural light photography is performed with this illumination light, a photograph with an extremely unnatural color is obtained. The problem of being reproduced arises. Therefore, in such a case, it is preferable to correct the color temperature by performing flash light emission.

(B) R _L <A ≤ R _H , r _L ≤ DELTA (STEP67) The brightness signal A of the middle area including the focus detection point is larger than the predetermined value R _L set on the low brightness side and is on the high brightness side. This is the case where the luminance difference signal DELTA is smaller than the set predetermined value R _H and is larger than the predetermined value r _L. In such a case, the main subject is placed outdoors in the shade, and the brightness difference from the background is large, and it can be determined that the scene is a general backlight scene. When natural light shooting is performed in such a backlit scene, the main subject portion will be underexposed considerably when trying to give a suitable exposure to the entire screen on average, and it is also desirable to give a suitable exposure to the main subject portion. In that case, the background portion is considerably overexposed, and it is difficult to give a 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 photographing in which the main subject portion is illuminated with flash light and the background portion where the flash illumination light does not reach is taken with natural light.

Here, the brightness difference signal DELTA is the maximum value MAX of the brightness signals of 15 small areas and the brightness signal A of the small area including the focus detection point.
The difference is. The maximum brightness signal MAX extracts the brightness signal of a high brightness subject such as the sky, cloud, or sun arranged in 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 the brightness in the vicinity thereof are extracted, it is possible to relatively accurately determine whether or not the scene is a backlight scene by using the difference between them.

(C) R _L <A ≤ R _H , DELTA <r _L (STEP68) The luminance signal A of the middle area including the focus detection point is larger than the predetermined value R _L set on the low luminance side and is on the high luminance side. This is the case where the brightness difference signal DELTA is smaller than the set predetermined value R _H and smaller than the predetermined value r _L. In such a case, the main subject is placed outdoors in the shade, and high-luminance subjects such as the sky and clouds are not placed in the shooting screen, and there is relatively little variation in the luminance signal. In such a case, you can get good exposure with natural light shooting,
It is better not to use flash light.

(D) R _H <A, r _H ≦ DELTA (STEP69) The luminance signal A in the middle area including the focus detection point is larger than the predetermined value R _H set on the high luminance side, and the luminance difference signal DELTA is the above-mentioned predetermined value. This is the case where it is larger than a predetermined value r _H which is slightly smaller than r _L. In such a case, 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 backlight scene against the sky or clouds. Then, it is assumed that the main subject is slightly small and the luminance signal A of the area including the focus detection point is already slightly affected by the background and a signal having a slightly higher luminance than the luminance of the main subject is output. Therefore, in such a case, it is preferable to perform flash light emission in the same manner as in the case of (b) and perform daytime synchronized photography.

Here, the predetermined values r _H and r _L for determining whether or not the scene is a backlit scene are r _H <r _L. In the case of a backlit scene, the background is usually a sky or cloud with high brightness, but the brightness is rarely lower than the predetermined brightness (about Bv8), so the main subject Brightness difference in a backlit scene when the brightness is less than a predetermined value R _H
DELTA becomes large, and in the backlight scene where the brightness of the main subject is larger than the predetermined value R _H , the brightness difference DELTA may not be so large. Assuming a backlit scene in which there is a similar brightness difference between the main subject and the background, when the main subject becomes slightly smaller, the luminance signal of the area including the focus detection point is Not only the luminance but also the luminance of the background is affected, and as a result, the area luminance signal A increases and the luminance difference signal DELTA tends to decrease. In consideration of the phenomenon described above, the predetermined value for determining whether or not the scene is a backlight is defined as a predetermined value r _H on the high brightness side and a predetermined value r _L on the low brightness side as r _H <r _L
It is configured to have a relationship.

(E) R _H <H, DELTA> r _H The brightness signal A of the middle area including the focus detection point is larger than the predetermined value R _H set on the high brightness side, and the brightness difference signal DELTA is the predetermined value r
If less than _H. In such a case, the main subject is placed outdoors in the sun, and the shooting screen has a substantially uniform high brightness. In such a case, as in the case of (c), it is preferable not to perform flash light emission because good exposure can be obtained by natural light photography.

In the present embodiment, as described above, the situation of the object scene is classified into five cases, and it is determined whether or not the flash light emission should be performed.

FIG. 10 is a flow chart showing the STEP08 photometric value calculation subroutine of FIG.

STEP 81: Photometric value calculation subroutine.

STEP 82: It is determined whether or not the flash setting signal FLSH is FLON. When FLSH = FLON, proceed to STEP86, and when FLSH ≠ FLON, that is, FLSH = FLOFF, proceed to STEP83.

STEP83: Since the natural light shooting mode is selected, evaluation metering is calculated. Using all of the average brightness signal A in the middle area around the focus detection point, the average brightness signal B in the surrounding middle area, and the average brightness signal C in the surrounding middle area around the focus detection point obtained in STEP37 to STEP39. Then, the weighted average luminance signal E ₀ of substantially the entire screen, in which the degree of importance in the vicinity of the focus detection point is increased, is obtained from the following equation.

E ₀ = (A + B + C) / 3 In the above equation, the luminance signals A, B, C in the three middle regions are simply added and averaged, but the area of the middle region near the focus detection point is S (A), If the area of the surrounding middle area is S (B) and the area of the surrounding middle area is S (C),
Since the area ratio of the three middle areas is S (A): S (B): S (C) = 1: 4: 10, by performing this calculation, the importance in the vicinity of the focus detection point is increased. The weighted average luminance is calculated. At this time, the priority levels J (A) of the three middle areas A, B, C,
J (B) and J (C) are proportional to the reciprocal of the area ratio, and J (A): J (B): J (C) = 1: 0.25: 0.1. In the following description, the calculation for obtaining E ₀ in the above equation is referred to as “focus detection point weighted average photometry”.

STEPP84: Area brightness calculation subroutine By using the average brightness signal of the middle area obtained in STEP06 and the difference between those average brightness signals, the correction value selection subroutine that analogizes the shooting situation and selectively determines the exposure correction value α is there. Details will be described later.

STEP 85: Automatic exposure correction is performed by adding the exposure correction value α output from the correction value selection subroutine to the focus detection point weighted average photometry E ₀ described above, and the photometric value E is calculated by the following equation.

E = E ₀ + α The photometric value E obtained by STEP83 to STEP85 is the photometric value by the evaluation photometry of this embodiment.

STEP86: Since the flash photography mode has been selected in STEP82, the metering value calculation during flash photography is performed. During flash photography, the main subject portion can be adjusted to an appropriate exposure level by illuminating with flash light and performing light control, so it is desirable to control so as to give a suitable exposure mainly to the background portion. Therefore, in the present embodiment, by using the area luminance signals B and C output from the area luminance calculation subroutine STEP06, the photometric value is obtained by the following equation in order to give a suitable exposure to the background portion other than the main subject portion. .

E = (B + C) / 2 In the present embodiment, during flash photography, the photometric value is obtained using the luminance signal of the peripheral region other than the region near the focus detection point selected as in the above formula.

Even in flash photography at low brightness, the exposure is assumed to be controlled by the above formula, but in the case of low brightness, in general, AE calculation that prevents the shutter time from becoming too long to prevent camera shake etc. Is often performed in STEP09 of FIG. 5, in which case the exposure is determined by another calculation and the above equation is not used.

STEP87: Return to the main routine.

As described above, in the photometric value calculation subroutine, it is possible to perform photometric value calculation that gives appropriate exposure to the main subject and the entire screen, or the background area in conjunction with the selection of the focus detection point during both natural light shooting and flash shooting. There is.

FIG. 11 is a flow chart showing the STEP84 correction value selection subroutine of FIG.

STEP 101: Correction value selection subroutine.

STEP 102: 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 around the focus detection point, the brightness signals of the adjacent middle areas The difference between A and B, the difference between B and C, and ΔBA and ΔCB are calculated by the following equations.

ΔBA = B−A ΔCB = −B STEP103: The average brightness signal C in the surrounding middle area is converted into a signal K corresponding to a predetermined brightness (here, whether it is an outdoor situation or an indoor situation. The value of
Check the approximate brightness of the scene. The reason why the average brightness signal C of the peripheral middle region is used here is that it is not affected by the reflectance of the main subject and is most suitable for inferring the situation where the main subject is placed. When C ≧ K, that is,
When it is determined that the situation is outdoors, the process proceeds to STEP 104. When C <K, that is, when it is determined that the condition is indoors, the process proceeds to STEP 121.

STEP104: The average brightness of the surrounding middle area is higher than the predetermined value K,
When it is judged that it is an outdoor scene, first the brightness difference Δ
Compare BA with a predetermined value P _H1 having a positive sign. If ΔBA <P _H1 , proceed to STEP 105. If ΔBA ≧ P _H1 , proceed to STEP 106.

Step 105: When ΔBA <P _H1 , further compare ΔBA with a predetermined value P _H2 having a negative sign. If ΔBA <P _H2 , STEP110
If ΔBA ≧ P _H2 , that is, if P _H2 ≧ ΔBA <P _H1 , the process proceeds to STEP 108.

The brightness difference ΔBA is classified into the following three types according to STEP104 and STEP105.

P _H1 ≦ ΔBA; ΔBA is a positive value with a large absolute value P _H2 ≦ ΔBA <P _H1 ; ΔBA is a small absolute value.

ΔBA <P _H2 ; ΔBA is a negative value with a large absolute value.

STEP106: When P _H1 ≤ΔBA, further compare ΔCB with a predetermined value Q _H1 having a positive sign. If ΔCB <Q _H1 , proceed to STEP 107. If ΔCB ≦ Q _H1 , proceed to STEP 112.

STEP107: When ΔCB <Q _H1 , further compare ΔCB with a predetermined value Q _H2 having a negative sign. STEP114 when ΔCB <Q _H2
When ΔCB ≦ Q _H2 , that is, when Q _H2 ≦ ΔCB <Q _H1 , the process proceeds to STEP113.

The brightness difference ΔCB is classified into the following three types according to STEP106 and STEP107.

Q _H1 ≤ ΔCB; ΔCB has a large absolute value. Positive value Q _H2 ≤ ΔCB <Q _H1 ; ΔCB has a small absolute value.

ΔCB <Q _H2 ; ΔCB is a negative value with a large absolute value.

STEP108: When P _H2 ≤ ΔBA <P _H1 , further compare ΔCB with a predetermined value Q _H1 having a positive sign. STEP11 when ΔCB <Q _H1
Go to step 5, and if ΔCB ≤ Q _H1 , go to step 109.

STEP109: When ΔCB <Q _H1 , further compare ΔCB with a predetermined value Q _H2 having a negative sign.

If ΔCB <Q _H2 , proceed to STEP 117, and if ΔCB ≤ Q _H2 ,
That is, when Q _H2 ≤ ΔCB <Q _H1 , the process proceeds to STEP116.

Brightness difference ΔCB can be calculated by STEP108 and STEP109.
It is divided into the same 3 categories as the one performed in 07.

STEP110: When ΔBA <P _H2 , further compare ΔCB with a predetermined value Q _H1 having a positive sign. If ΔCB <Q _H1 , proceed to STEP118, and if ΔCB ≦ Q _H1 , proceed to STEP111.

STEP111: When ΔCB <Q _H1 , further compare ΔCB with a predetermined value Q _H2 having a negative sign. STEP 120 if ΔCB <Q _H2
When ΔCB ≦ Q _H2 , that is, when Q _H2 ≦ ΔCB <Q _H1 , the process proceeds to STEP119.

Brightness difference ΔCB can be calculated by STEP110 and STEP111.
It is classified into the same three ways as done in P107.

When it is judged in STEP 103 that it is an outdoor scene,
As described above, in STEP 104 to STEP 111, the situation of the object scene is classified into 9 types and the exposure correction value α is selected.

STEP112 to STEP120: The exposure correction value α suitable for the field situation classified by STEP104 to STEP111 is output. In the present embodiment, the value of α is only three values α _H1 , α _H2 and 0 (provided that α _H1 <α _H2 <0), and one of these three values is selected. There is. A method of determining the exposure correction value α will be described later.

STEP121: The average brightness of the surrounding middle area is lower than the predetermined value K,
When it is determined that the scene is an indoor scene, first the brightness difference Δ
Compare BA with a predetermined value P _L1 having a positive sign. If ΔBA <P _L1 , proceed to STEP122. If ΔBA ≦ P _L1 , proceed to STEP123.

STEP122: When ΔBA <P _L1 , further compare ΔBA with a predetermined value P _L2 having a negative sign. If ΔBA <P _L2 , STEP127
If ΔBA ≦ P _L2 , that is, if P _L2 ≦ ΔBA <P _L1 , the process proceeds to STEP125.

The brightness difference ΔBA is classified into the following three types according to STEP121 and STEP122.

P _L1 ≤ ΔBA; ΔBA is a positive value with a large absolute value.

P _L2 ≤ ΔBA <P _L1 ; ΔBA has a small absolute value.

ΔBA <P _L2 ; ΔBA is a negative value with a large absolute value.

STEP123: When P _L1 ≤ΔBA, ΔCB is further compared with a predetermined value Q _L1 having a positive sign. If ΔCB <Q _L1 , proceed to STEP124, and if ΔCB ≦ Q _L1 , proceed to STEP129.

STEP124: When ΔCB <Q _L1 , further compare ΔCB with a predetermined value Q _L2 having a negative sign. STEP131 when ΔCB <Q _L2
When ΔCB ≦ Q _L2 , that is, when Q _L2 ≦ ΔCB <Q _L1 , the process proceeds to STEP 130.

The brightness difference ΔCB is classified into the following three types according to STEP123 and STEP124.

Q _L1 ≤ ΔCB; ΔCB is a positive value with a large absolute value.

Q _L2 ≤ ΔCB <Q _L1 ; ΔCB has a small absolute value.

ΔCB <Q _L2; ΔCB negative values greater in absolute value.

STEP125: When P _L2 ≤ ΔBA <P _L1 , further compare ΔCB with a predetermined value Q _L1 having a positive sign. STEP12 if ΔCB <Q _L1
Go to step 6, and if ΔCB ≤ Q _L1 , go to step 132.

STEP126: When ΔCB <Q _L1 , further compare ΔCB with a predetermined value Q _L2 having a negative sign. If ΔCB <Q _L2 , STEP134
If ΔCB ≦ Q _L2 , that is, if Q _L2 ≦ ΔCB <Q _L1 , the process proceeds to STEP133.

Brightness difference ΔCB can be calculated by STEP125 and STEP126.
It is classified into the same three ways as done in P124.

STEP127: When ΔBA <P _L2 , further compare ΔCB with a predetermined value Q _L1 having a positive sign. If ΔCB <Q _L1 , proceed to STEP128, and if ΔCB ≦ Q _L1 , proceed to STEP135.

STEP128: When ΔCB <Q _L1 , further compare ΔCB with a predetermined value Q _L2 having a negative sign. STEP13 if ΔCB <Q _L2
7. If ΔCB ≦ Q _L2 , that is, if Q _L2 ≦ ΔCB <Q _L1 , proceed to STEP 136.

Brightness difference ΔCB is calculated by STEP127 and STEP128.
There are three categories, similar to what we did in 124.

When it is determined in STEP 103 that it is an indoor scene,
As described above, in STEP121 to STEP128, the situation of the object scene is classified into nine types and the exposure correction value α is selected.

STEP129 to STEP137: The exposure correction value α suitable for the field situation classified by STEP121 to STEP128 is output. In the present embodiment, the value of α is only three values of α _L1 , Q _L2 and 0 (where α _L1 <0 <α _L2 ) and any one of these three values is selected. There is. A method of determining the exposure correction value α will be described later.

STEP 138: Return to photometric value calculation subroutine.

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

Next, a method of determining the exposure correction value α will be described. Eighteen states classified into STEP112 to STEP120 and STEP129 to STEP137 in FIG. 11 are expressed in a coordinate plane having ΔBA and ΔCB as both coordinate axes, as shown in FIGS. 13 (a) and (b). Become. In addition, STEP112 to STEP120 and STEP129 to STEP137 of FIG.
The above state is as shown in FIGS. 14 (a) and 14 (b) when the luminance signals A, B, C of the respective middle regions are shown by bar graphs. FIG. 14 also schematically shows the focus detection point weighted average photometric value E ₀ , the exposure correction value α, and the evaluation photometric value E in each situation. The situation of the object field under each condition and the method of determining the exposure correction value α will be described below with reference to FIGS. 13 and 14.

(A) When K ≦ C: Outdoor scene (ai) P _H1 <ΔBA, Q _H1 <ΔCB (STEP112) As shown in FIG. 13 (a), ΔBA is greater than the predetermined positive value P _H1 . If ΔCB is larger than a predetermined positive value Q _H1 , the first
This is the case of the brightness distribution as shown in (i) of FIG. In such a case, since the background part has high brightness and the main subject part has relatively low brightness, it can be generally estimated that the scene is a backlight scene. Moreover, since the luminance signal A, the luminance signal B, and the luminance signal C are changed in a stepwise manner, the main subject arranged near the focus detection point has an area for outputting the luminance signal A and an area for outputting the luminance signal B. It is thought that it exists for a part of. In the case of such a brightness distribution, the focus detection point weighted average photometric value E ₀ is an output as shown in the figure, but while sufficiently considering the brightness of the main subject described above,
Considering the background brightness to some extent, in order to give a proper exposure, the correction value α _H1 with a negative sign and a relatively large absolute value is used.
It is preferable to output the evaluation photometric value E as shown in FIG. 14 (a) (i).

(A-ii) P _H1 <ΔBA, Q _H2 <ΔCB ≤ Q _H1 (STEP113) As shown in Fig. 13 (a), ΔBA is larger than the positive predetermined value P _H1 , and ΔCB is the negative predetermined value Q. _{This is the} case where it is larger than _H2 and smaller than the positive predetermined value Q _H1 , and the luminance distribution is as shown in (ii) of FIG. 14 (a). Even in this case,
As in the case of (i), it can be estimated that it is a backlight scene.
Focusing on the variation in the luminance signal, it is considered that only the luminance signal A has a relatively low luminance, and the main subject is arranged only in the area where the luminance signal A is output. Also,
In such a case, the size of the main subject may be approximately the same as the area in which the luminance signal A is output or slightly smaller than this area. In the former case, the luminance difference ΔBA
Appears relatively large, and in the latter case, the luminance signal A itself is already affected by the luminance of the background, and the luminance difference Δ
BA tends to be relatively small. In any case, when it is detected that the brightness difference ΔBA is larger than the predetermined positive value P _H1 and a relatively low-brightness main object is located near the focus detection point, the focus as shown in the figure is displayed. With respect to the detection-point-weighted average photometry value E ₀ , the brightness of the main subject is fully taken into consideration, the brightness of the background is also taken into account, and the evaluation value is measured using the correction value α _H1 that is approximately the same as in (i) It is good to output the value E.

(A-iii) P _H1 <ΔBA, ΔCB ≤ Q _H2 (STEP114) As shown in Fig. 13 (a), ΔBA is larger than the positive predetermined value P _H1 and ΔCB is smaller than the negative predetermined value Q _H2. If in the first
This is the case of the luminance distribution as shown in (iii) of FIG. Such a brightness distribution appears when a high-brightness subject is locally present in the area where the brightness signal B is output. In such a case, if the correction is performed so as to eliminate the influence of the local high-brightness subject, it becomes possible to give a suitable exposure to the entire screen. Therefore, in (ii) of FIG.
As shown in i), it is preferable to output the evaluation photometric value E using the correction value α _H2 having a negative sign and a relatively small absolute value.

(A-iv) P _H2 <ΔBA ≦ P _H1 , Q _H1 <Δ CB (STEP115) As shown in FIG. 13 (a), ΔBA is larger than the negative predetermined value P _H2 and larger than the positive predetermined value P _H1 . This is the case where ΔCB is small and ΔCB is larger than a predetermined positive value Q _H1 , and the luminance distribution is as shown in (iv) of FIG. 14 (a). In such a case as well, it can be estimated that it is a backlight scene as in the case of (i).
Focusing on the variation of the luminance signal, the luminance signal A and the luminance signal B have lower luminance than the luminance signal C, and the main subject is referred to as an area outputting the luminance signal A and an area outputting the luminance signal B. It is thought that they are distributed over a fairly wide area. In the case of such a brightness distribution, it is better to output a photometric value that places more importance on the area determined to be the main subject, but the focus detection point-weighted average photometric value E ₀ has a slightly high brightness as shown in the figure. Since it is affected by the brightness of the background area, it is preferable to output the evaluation photometric value E using the correction value α _H2 that is substantially the same as that in (iii).

(Av) P _H2 <ΔBA ≤ P _H1 , Q _H2 <ΔCB ≤ Q _H1 (STEP116) As shown in Fig. 13 (a), ΔBA is larger than the negative predetermined value P _H2 and is positive predetermined. If the brightness difference is smaller than the value P _H1 and ΔCB is larger than the negative predetermined value Q _H2 and smaller than the positive predetermined value Q _H1 , and the brightness difference is small as shown in (v) of FIG. 14 (a). is there. Such a brightness distribution is (i
In the backlight scene where the size of the main subject becomes even smaller in the scene similar to the case of i) and it becomes difficult to detect the brightness of the main subject part, and in the scene similar to the case of (iv), the main subject It is assumed that the size of the image becomes even larger and a landscape scene or the like in which a substantially entire screen is the main subject. Even in a backlit scene where the main subject is small, it is better to handle it as a backlit scenery scene under such a situation. Therefore, the focus detection point weighted average photometry is set to 0 for the correction value so as to give proper exposure to the entire screen. It is preferable to output the value E _{0 as it} is as the evaluation photometric value E.

(A-vi) P _H2 <ΔBA ≤ P _H1 , ΔCB ≤ Q _H2 (STEP117) As shown in Fig. 13 (a), ΔBA is larger than the negative predetermined value P _H2 and larger than the positive predetermined value P _H1 . This is the case where ΔCB is small and ΔCB is smaller than a predetermined negative value Q _H2 , and the luminance distribution is as shown in (vi) of FIG. 14A. Such a brightness distribution appears in the area where the brightness signal A is output and in the brightness signal B.
This is the case where a main subject having a considerably high luminance is arranged in both of the areas for outputting, and in many cases, with respect to the luminance signal C indicating the general brightness as described above, the main subject having a considerably high luminance is displayed. The subject is a subject with high reflectance (whitish). Therefore, in such a case, as shown in the figure, the main subject part is depicted as whitish (ii
Evaluative photometric value E using the correction value α _H2 that is almost the same as in case i)
Is good to output.

(A-vii) ΔBA ≦ P _H2 , Q _H1 <ΔCB (STEP118) As shown in FIG. 13 (a), ΔBA is smaller than a negative predetermined value P _H2 and ΔCB is larger than a positive predetermined value Q _H1. If in the first
This is the case of the brightness distribution as shown in (vii) of FIG. Such a brightness distribution appears when the main subject itself has a considerable contrast ratio or a landscape scene with a special composition, but it is not a general scene and the frequency is also low. Few. In such a case, it is preferable to give a proper exposure to the entire screen. As in the case of (v), the correction value is set to 0, and the focus detection point weighted average photometry value E ₀ is evaluated as it is. It is good to output as the value E.

(A-viii) ΔBA ≦ P _H2 , Q _H2 <ΔCB ≦ Q _H1 (STEP119) As shown in FIG. 13 (a), ΔBA is smaller than the negative predetermined value P _H2 and ΔCB is the negative predetermined value Q. _When it is larger than _H2 and smaller than a predetermined positive value Q _H1 , (viii) in FIG. 14 (a).
This is the case of the brightness distribution as shown in. In such a case, as in the case of (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 that in the case of (vi). In the case of such an object, it is necessary to depict the main object part whitish to some extent, but if the focus detection point weighted average photometric value E ₀ is used as it is, it is possible to give almost the desired exposure. Therefore, it is preferable to output the evaluation photometric value E using the correction value 0.

(A-ix) ΔBA ≦ P _H2 , ΔCB ≦ Q _H2 (STEP120) As shown in FIG. 13 (a), ΔBA is smaller than the negative predetermined value P _H2 and ΔCB is smaller than the negative predetermined value Q _H2. If in the first
This is the case of the brightness distribution as shown in (ix) of FIG. In such a case, it is estimated that the subject is the same as in the case of (vi), and the size of the main subject can be determined to be an intermediate size between the case of (vi) and the case of (viii).
Further, in such a case, the area near the focus detection point has higher brightness than in the cases of (vi) and (viii),
It can be determined that a subject having a higher reflectance is placed or a light source is placed. In such a case, even if the focus detection point weighted average photometric value E ₀ is used as it is, the main subject part is depicted as whitish to some extent, but the main subject part is considered in consideration of the balance with the peripheral part of the screen. To make the image more whitish, (ii
It is preferable to output the evaluation photometric value E by using the correction value α _H2 that is substantially the same as i).

(B) When C <K: Indoor scene (b-i) P _L1 <ΔBA, Q _L1 <ΔCB (STEP129) As shown in FIG. 13 (b), ΔBA is larger than a predetermined positive value P _L1. , ΔCB is greater than a predetermined positive value Q _L1 , the 14th
This is the case of the luminance distribution as shown in (i) of FIG. In such a case, the background part is not very bright and the main subject part is considerably lower in brightness than the background part, so that the main subject is placed in a position where it is not illuminated by the illumination light in the room. Scenes etc. are assumed. In addition, a scene in which a subject having a slightly low reflectance (blackish) is arranged near the focus detection point is also assumed. Further, it is considered that the size of the main subject exists in the area where the luminance signal A is output and a part of the area where the luminance signal (b) is output as in the case of (a-i). Under such conditions, in order to depict the situation of the object scene observed by the photographer according to the sense of the photographer, the main subject portion does not have to reproduce its detail portion.
It is desirable to give exposure that is described as a little black. Therefore, as shown in (i) of FIG. 14 (b),
It is preferable to obtain the evaluation photometric value E by using a correction value α _L1 having a negative sign and a relatively small absolute value with respect to the focus detection point weighted average photometric value E ₀ .

(B-ii) P _L1 <ΔBA, Q _L2 <ΔCB ≤ Q _L1 (STEP 130) As shown in Fig. 13 (b), ΔBA is larger than the positive predetermined value P _L1 and ΔCB is the negative predetermined value Q. _The case where it is larger than _L2 and smaller than the positive predetermined value Q _L1 is the case of the luminance distribution as shown in (ii) of FIG. 14 (b). Even in such a case, it can be estimated that the main subject portion is a dark scene as in the case of (i). The size of the main subject is (a-i
Similar to i), it can be determined that it is slightly smaller than the case of (i). Even in such a case, as in the case of (i),
It is desirable to depict the main subject portion in a slightly blackish color. Therefore, as shown in the figure, it is preferable to output the evaluation photometric value E using the correction value α _L1 that is substantially the same as in the case of (i).

(B-iii) P _L <ΔBA, ΔCB ≤ Q _L2 (STEP131) As shown in Fig. 13 (b), ΔBA is larger than a predetermined positive value P _L1 and ΔCB is smaller than a predetermined negative value Q _L2. If in the first
This is the case of the luminance distribution as shown in (iii) of FIG. Such a brightness distribution appears when there is a locally high brightness subject 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 ₀ is influenced by this high-brightness region and renders the main subject part slightly black, which provides a suitable exposure for such a scene. As shown in the figure, it is preferable to set the correction value to 0 and output the focus detection point weighted average photometric value E ₀ as the evaluation photometric value E as it is.

(B-iv) P _L2 <ΔBA ≦ P _L1 , Q _L1 <Δ CB (STEP 132) As shown in FIG. 13 (b), ΔBA is larger than the negative predetermined value P _L2 and the positive predetermined value P _When LCB is smaller than _L1 and ΔCB is larger than a predetermined positive value Q _L1 , (iv) in FIG. 14 (b).
This is the case of the brightness distribution as shown in. Even in such a case, it can be estimated that the main subject portion is a dark scene as in the case of (i). The size of the main subject is (a-i
Similar to (v), it can be determined that it is larger than in (i) and is arranged over a fairly wide area of the shooting screen. Even in such a case, it is desirable to depict the main subject part to be slightly black as in the case of (i), but as shown in the figure, the focus detection point weighted average photometry value E ₀ is set to give a fairly suitable exposure as it is. Since it is a large value, the correction value is set to 0 and the focus detection point weighted average photometry value
It is good to output E ₀ as it is as an evaluation photometric value.

(B-v) P _L2 <ΔBA ≤ P _L1 , Q _L2 <ΔCB ≤ Q _L2 (STEP133) As shown in Fig. 13 (c), ΔBA is larger than the negative predetermined value P _L2 and is positive. When the brightness difference is smaller than the value P _L1 and ΔCB is larger than the negative predetermined value Q _L2 and smaller than the positive predetermined value Q _L1 , and the brightness difference is small as shown in (v) of FIG. 14 (b). is there. Such a brightness distribution appears in the same situation as (av), but in an indoor scene, in particular, a bright part and a dark part are mixed in each region, and the brightness signals A, B, and C are output as the middle region. At this time, there are not a few scenes in which the brightness difference is small as a result. In such a case, as in (av), the correction value is set to 0 so as to give proper exposure to the entire screen, and the focus detection point weighted average photometric value E ₀ is output as it is as the evaluation photometric value E. Is good.

(B-vi) P _L2 <ΔBA ≤ P _L1 , ΔCB ≤ Q _L2 (STEP134) As shown in Fig. 13 (b), ΔBA is larger than the negative predetermined value P _L2 and is also the positive predetermined value P _L1. This is the case where ΔCB is smaller and ΔCB is smaller than a predetermined negative value Q _L2 , and the luminance distribution is as shown in (vi) of FIG. 14B. Such a brightness distribution appears because the main subject exists in both the area outputting the brightness signal A and the area outputting the brightness signal B, the main object is illuminated by the illumination light, and the other background area is present. For example, when the brightness is relatively high. In such a case, in order to give a suitable exposure that gives importance to the main subject portion while giving some consideration to the luminance signal of the background portion, as shown in the drawing, the correction value α with a positive sign _It is preferable to output the evaluation photometric value E using _L2 .

(B-vii) ΔBA ≦ P _L2 , Q _L1 <ΔCB (STEP135) As shown in FIG. 13 (b), ΔBA is smaller than the negative predetermined value P _L2 and ΔCB is smaller than the positive predetermined value Q _L1 . In case of big,
This is the case of the luminance distribution as shown in (vii) of FIG. 14 (b). Such a brightness distribution appears (a-vii)
Similar to the above, there is a special situation, and in this case (a-vi
It is preferable to give proper exposure to the entire screen as in the case of i). Therefore, the correction value is set to 0, and the focus detection point weighted average photometric value E ₀ is output as it is as the evaluation photometric value E. good.

(B-viii) ΔBA ≦ P _L2 , Q _L2 <ΔCB ≦ Q _L1 (STEP136) As shown in FIG. 13 (b), ΔBA is smaller than the negative predetermined value P _L2 and ΔCB is the negative predetermined value Q. _When it is larger than _L2 and smaller than a predetermined positive value Q _L1 , (vii in FIG. 14B).
This is the case of the brightness distribution as shown in i). In such a case, as in the case of (vi), it can be estimated that only the main subject portion has a relatively high brightness due to illumination light or the like. Also, the size of the main subject portion can be determined to be smaller than that in the case of (vi) from the distribution state of the luminance signal. In such a case, in order to give an exposure in which the luminance signal of the main subject portion is emphasized and the luminance signal of the background is taken into consideration,
As shown in the figure, for the focus detection point weighted average photometry value E ₀ ,
It is preferable to output the evaluation photometric value E using the correction value α _L2 that is substantially the same as in the case of (vi).

(B−ix) ΔBA ≦ P _L2 , ΔCB ≦ Q _L2 (STEP137) As shown in FIG. 13 (b), ΔBA is smaller than the negative predetermined value P _L2 and ΔCB is smaller than the negative predetermined value Q _L2. If in the first
This is the case of the brightness distribution as shown in (ix) of FIG. In such a case, the subject is estimated to be the same as in (vi), and the size of the main subject can be determined to be an intermediate size between (vi) and (viii). . Further, in such a case, compared to the cases of (vi) and (viii), the area near the focus detection point has higher brightness, and the main object illuminated by the illumination light or the like has a slightly higher reflectance. It is assumed that the scene is a high (slightly whitish) subject, or a lighting light source is arranged behind or in the vicinity of the main subject. In such a case, the area near the focus detection point is described as a little whitish, and the exposure considering the balance of the entire screen is given while giving importance to the main subject portion, as shown in (v
It is preferable to output the evaluation photometric value E using the correction value α _L2 that is substantially the same as in the case of i).

As described above, in this embodiment, the situation of the object scene is set to 18
It is configured so that the optimum exposure correction value α is selectively determined under each condition. The relationship between the magnitudes of the exposure correction values described above can be summarized as follows.

α _H1 <α _H2 <0 α _L1 <0 <α _L2 Also, regarding the magnitude relationship between α _H1 or α _H2 and α _L1 ,
Depending on the setting of the predetermined values P _H1 , P _H2 , Q _H1 , Q _H2 , P _L1 , P _L2 , Q _L1 , and Q _L2 , when the brightness differences ΔBA and ΔCB are approximately equal values, it is generally It is desirable that _H2 <α _L1 .

In the method of determining the exposure correction value α described above, in order to simplify the description, the classification of the field based on the brightness differences ΔBA and ΔCB is 9
I went through each street, but for example
In particular, in a situation where the selection result of the exposure correction value α greatly changes according to the brightness difference, such as the classification of the states (ii) and (v), a more detailed classification is performed. It is desirable to do so. Further, it is desirable to perform more detailed classification even in the case of classifying the object scene based on the luminance signal c. By categorizing the object field more closely in this way, it is possible to obtain stable exposure by reducing the exposure unevenness when the shooting composition changes slightly.

It should be noted that the photometric device configured to use the above-mentioned luminance signal differences ΔBA and ΔCB and the luminance signal c in the peripheral portion of the photographic screen to output a proper photometric value by advancing the situation of the object scene. JP-A-62-184319.

In addition, the focus detection point weighted average photometry in the present embodiment is a calculation for obtaining an addition average value with 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 coefficient of importance of each area is shown in FIGS. ), (C). It goes without saying that the combination of the coefficients of importance is not limited to this.

Further, in the above-described embodiment, the determination of the flash photography condition is performed by classifying into three stages based on the value of the luminance signal A in the area near the focus detection point. However, since a more detailed condition determination is performed,
It goes without saying that the more detailed the classification, the more effective it is. In the description of the above embodiment, the brightness difference DELTA
Is compared with the predetermined value only when the brightness is high, but it can be considered that the value is compared with the predetermined value 0 even when the brightness is low.
When determining the flash emission condition based on the brightness A of the predetermined region, the flash emission condition is determined by changing the predetermined value for comparing the brightness difference DELTA into three levels of 0, r _L , and r _H. Can be characterized as

[Other Examples]

FIGS. 16 (a) and 16 (b) are views showing the divided shape of the photometric light receiving portion of another embodiment of the present invention. In the first embodiment of the present invention, the photometric light-receiving portion is divided into 15 small regions having the same shape, but may be divided into small regions having different shapes and areas as shown in FIG. However, in such a case, when classifying the luminance signals of the small areas into the middle areas, it is necessary to take care so that the area of each middle area is not significantly changed by the selection of the focus detection points.

In FIGS. 16 (a) and 16 (b), the object scene is divided into 11 small areas for photometry.
Reducing the number of divisions has the advantages of simplifying the photometric circuit and reducing the cost of the photometric light-receiving element. When the photometric light receiving section is divided as shown in FIG. 16, the light receiving small areas arranged in the peripheral area of the shooting screen are connected in series to reduce the effective number of photometric light receiving sections. , Can be less. A technique for reducing the number of divisions of the light receiving portion for photometry in this manner is disclosed in Japanese Patent Application Laid-Open No. 60-125527 of the same applicant.

〔The invention's effect〕

According to the present invention, the first brightness information of the photometric area including the focus detection area selected from the plurality of photometric areas, and the second brightness information indicating the maximum value.
Brightness information, and by comparing this comparison information with a predetermined value that changes depending on the value of the first brightness information, the necessity of flash light emission was determined, so, for example, in a sunny scene or a shaded scene, Even in various scenes, it is possible to accurately determine the necessity of flash light emission.

[Brief description of drawings]

FIG. 1 is a diagram showing a divided shape of a photometric light receiving portion of a first embodiment of the present invention, FIG. 2 is a sectional view of an optical system of a camera of a first embodiment of the present invention, and FIG. FIG. 4 is a perspective view of a multi-point focus detection optical system of the first embodiment, FIG. 4 is a diagram showing the circuit configuration of a camera of the first embodiment of the present invention, and FIGS. 5 to 11 are the first embodiment of the present invention. FIG. 12 to FIG. 15 are explanatory views for explaining the flow chart of the first embodiment of the present invention, and FIG. 16 is a divided shape of the photometric light receiving portion of another embodiment of the present invention. Fig. 1 ... Photometric light receiving unit 15 ... Focus detection light receiving unit 22 ... Central processing unit CPU

Claims (1)

[Claims] 1. A camera provided with a focus detection unit configured to independently detect the focus of a plurality of areas within a photographing screen, wherein a photometric range is divided into a plurality of photometric areas, and the brightness of each of the divided photometric areas is determined. Light receiving means for detecting, first brightness information of a photometry area including a focus detection area selected from the plurality of focus detection areas, and second brightness indicating a maximum value in the plurality of photometry areas. The necessity of flash light emission is determined by comparing brightness comparison means for comparing information with the comparison information corresponding to the difference obtained by the comparison means with a predetermined value that changes depending on the value of the first brightness information. A camera provided with a judging means.