JP2692854B2 - Automatic exposure control device - Google Patents

Description

The present invention relates to an automatic exposure control device suitable for use in a video camera or the like.

(Prior Art) In video equipment such as video cameras, automatic exposure control has been conventionally performed, and in the case of constant exposure control such as video cameras, an optical system is used so that the video signal level is always constant. The aperture and the AGC circuit are controlled by feedback control.

FIG. 9 is a block diagram showing a general configuration of a conventional automatic exposure control device used in a video camera.

In the figure, 1 is a taking lens, 2 is an exposure control unit including a diaphragm for controlling the amount of incident light incident through the taking lens 1, and 3 is image information formed by the taking lens 1 on its imaging surface. An image pickup device such as a CCD for photoelectrically converting and outputting an image signal, 4 is a buffer amplifier provided on the output side of the image pickup device 3, an amplifier including an AGC circuit, and 5 is a gamma correction for the video signal output from the buffer amplifier 4. , Signal processing such as blanking processing and addition of synchronization signal is performed to convert it to a standardized NTSC signal, for example, and a signal suitable for supply to a monitor display (not shown) or a video recorder from the video output terminal. Signal processing circuit. A signal level detection circuit 6 detects the output signal level of the amplifier 4 and feeds back a control signal to the exposure control unit 2 and the AGC circuit in the amplifier 4 so that the signal level becomes a preset constant level. .

As a result, the video signal level always becomes a constant target value, and automatic exposure control can be performed.

However, in the above-described configuration, in this case, when the brightness difference between the subject and the background portion is large, the subject is crushed in black when the subject is backlit, and when the subject is normally illuminated, the subject becomes white and the image becomes unnatural.

In order to improve this phenomenon, a weighted metering method is used in which light is focused on a part of the shooting screen.

This weighted metering system is a system that sets a metering frame in the center of the shooting screen, sets the inside as a metering area, and controls so that the subject captured in the metering area is always exposed properly. is there.

FIG. 10 is a block diagram for explaining the configuration of this priority photometry method. The difference from the configuration of FIG. 7 is that only the video signal corresponding to the inside of the photometry frame at the center of the screen is detected by the signal level detection circuit 6 Circuit for opening and closing the signal supplied from the amplifier 4 to the signal level detection circuit 6 in order to supply
30 and a gate pulse generation circuit 31 for controlling the gate circuit 30 in accordance with the synchronizing signal SYNC and generating a gate pulse for passing only the signal within the photometric frame.

As a result, automatic exposure control is performed so that the subject within the photometric frame is always exposed properly without being affected by the background.

(Problems to be Solved by the Invention) However, according to the frame-weighted photometry method, the photometry area (photometry frame) is positionally fixed on the screen, and the exposure control is also called so-called backlight compensation and overexposure compensation. Therefore, when performing frame-weighted metering, i) If the subject and the camera move relative to each other and the subject moves out of the metering area, the brightness in the metering area will change. The brightness of the entire screen is changed, and at the same time, the brightness of the subject is changed, giving a very unnatural impression to the photographer.

ii) There is a risk of erroneously recognizing the subject and causing malfunction.

Therefore, it has been desired to realize an apparatus that always performs appropriate exposure control according to the state of the image on the screen.

(Means for Solving Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and is characterized in that it is a photometric device for performing intensive photometry on a subject in a shooting screen. A photometric frame setting means capable of moving the set position of the frame and a brightness level corresponding to the inside and outside of the photometric frame are respectively detected, and it is determined whether or not the difference between the brightness levels is a predetermined threshold value or more. Means and the exposure state is controlled based on the determination result of the determination means, and when the difference between the brightness levels inside and outside the photometric frame exceeds the threshold value, the brightness level corresponding to the brightness level inside the photometric frame is determined. When the weighting is increased to perform the intensive photometry on the brightness level inside the photometry frame, and the difference between the brightness levels inside and outside the photometry frame is less than or equal to the threshold value, the average brightness level inside and outside the photometry frame. Photometry And an exposure control unit for controlling the photometry frame setting unit so as to track the set position of the photometry frame with the movement of the subject image while operating the exposure control unit. The automatic exposure control device is such that a change in the exposure state due to the movement of the set position of the photometric frame by the frame tracking means can be corrected in parallel by the exposure control means.

(Operation) As a result, the state of the subject and its background can be discriminated, and exposure compensation such as backlight compensation and whiteout compensation can be automatically performed, and an appropriate exposure state can be maintained at all times. Even if is moved, the subject can be tracked by the photometric frame, and appropriate exposure control can be continuously performed in real time.

(Embodiment) An embodiment of the automatic exposure control apparatus according to the present invention will be described in detail below with reference to the drawings. Incidentally, FIG.
The same components as those of the conventional example shown in FIG. 10 will be described using the same reference numerals.

The individual configurations of the photographing lens 1, the exposure control unit 2, the image pickup device 3, the amplifier 4, and the signal processing device 5 are the same as those in FIGS. 9 and 10. MD is a monitor display of the video output of the signal processing circuit 5.

As shown in FIG. 2, 6 indicates a photometric frame 1 on the shooting screen 100.
This is a photometry frame setting circuit for setting 01 and setting the inner area EA and the outer area EB outside thereof. 7a, 7b, according to the gate pulse output from the gate pulse generation circuit 14,
The gate circuit 7a is a gate circuit for passing a video signal (luminance signal) corresponding to a designated area on the photographing screen 100, and the gate circuit 7a allows a video signal corresponding to an in-frame area EA in the photometric frame 101 on the photographing screen 100 to pass. On the other hand, the gate circuit 7b is an inverter for the gate pulse output from the gate pulse generation circuit 14.
Since the signal inverted by NOT is supplied, the video signal corresponding to the outside-frame area EB is passed through the background outside the photometric frame 101 on the photographic screen 100. 8a and 8b are integrating circuits for integrating the video signals inside and outside the photometric frame output from the gate circuits 7a and 7b in one field period, and 9a and 9b are
It is an area correction circuit for normalizing the integrated values output from the integrating circuits 8a and 8b by the area of each region. Since the area correction circuits 9a and 9b cannot compare the integrated outputs of the integration circuits 8a and 8b as they are because the areas Ea and Eb inside and outside the photometric frame 101 are different from each other, each integrated value is extracted. It is provided in order to normalize by the area of the created region and to make comparison as the average brightness level. Here, the average brightness level of each area
Ea and Eb.

10 is a subtracter that subtracts the integrated value of the luminance signal inside and outside the photometric frame output from the area correction circuits 9a and 9b to calculate the difference, and 11 is the result of the subtraction, that is, the area inside and outside the photometric frame
Absolute value circuit for obtaining the absolute value of the difference between the average brightness levels Ea and Eb in EA and EB, 12 is an A / D converter that converts the output of absolute value circuit 11 into a digital value, and 13 is an A / D converter Based on the absolute value of the brightness difference of the photometric area EA, EB converted into a digital value by 12 and the determination result of the determination circuit 15 described later, the gate pulse generation circuit 14 is controlled so that this brightness difference is maximized, This is a control microcomputer for controlling the position of the photometric frame 101 on the shooting screen. The gate pulse generation circuit 14 is a control microcomputer 13
The gate pulse generation timing is changed in accordance with the command (1), and the position where the photometric frame 101 is set on the passing portion in the video signal, that is, on the photographic screen 100 is changed. Further, a photometric frame display signal GD for displaying the position of the photometric frame 101 on the monitor display MD is supplied from the control microcomputer 13 to the signal processing circuit 5.

Generally, in the shooting screen, the main subject has a higher brightness level than the background (there are many high-frequency components).
Therefore, if you move the metering frame so that the brightness difference between the inside and outside of the metering frame is always maximized while the object is being captured by the metering frame 101, the metering frame will always track the subject and always capture the best subject. You can

A tracking algorithm for controlling the position of the photometric frame so that the brightness differences Ea and Eb between the areas EA and EB inside and outside the photometric frame are maximized will be described later.

Reference numeral 15 is a luminance difference between the area inside and outside the photometric frame 101 output from the subtraction circuit 10, that is, Ea-Eb is compared with a preset threshold level TH1, TH2 (TH1 <TH2), and A determination circuit for determining the state, that is, whether backlight compensation is required, overexposure compensation is required, or average photometry should be performed.The analog switch SW to be described later is based on the determination result.
A control signal C for controlling the opening and closing of is output.

When the average luminance level Ea of the area EA inside the photometric frame 101 is lower than the luminance level Eb of the area EB outside the photometric frame 101 and Ea-Eb <TH1, or the area EA inside the photometric frame is present.
When the average brightness level Ea of the area is larger than the brightness level Eb of the area EB outside the photometric frame and TH2 <Ea-Eb, the control signal C is set to the H level, and the average brightness level Ea, Eb of the areas EA and EB inside and outside the photometric frame is set. When the relationship of TH1 ≦ Ea−Eb ≦ TH2 is satisfied, the control signal C is operated to be at L level.

Reference numeral 16 is a photometric circuit that outputs a video signal level for photometry to the exposure control device 2 based on the determination result of the determination circuit 15, and 17 is a video signal in the area Eb outside the photometric frame 101 output from the gate circuit 7b. Is an integrating circuit for integrating and averaging over a predetermined period (1 field), 18 is an integrating circuit for integrating and averaging the video signals in the region Ea in the photometric frame 101 output from the gate circuit 7a during the same period, 19 is a buffer amplifier, SW is an open / close control by the control signal C of the discrimination circuit 15, and is an analog switch which is ON when the control signal C is H level and OFF when the control signal C is L level, and R _{1 to} R ₃ are exposed via the buffer amplifier 19. In controlling the video signal level fed back to the control device 2, a resistor for weighting each signal according to the inside and outside of the photometric frame, and 20 is an adder.

With the above configuration, the video signal, that is, the luminance signal output from the amplifier 4 is respectively supplied by the gate circuits 7a and 7b.
The signal Ea corresponding to the area EA inside the photometric frame and the signal Eb corresponding to the area EB outside the photometric frame are separately taken out, and as described above, the average luminance thereof via the integrating circuits 8a and 8b and the area correction circuits 9a and 9b. The level is obtained, and the subtraction circuit 10 calculates the level difference. Then, the difference Ea-Eb between the average luminance levels of the areas EA and Eb is input to the determination circuit 15, and the state of the screen is determined.

Now, as shown in FIG. 3 (c), when there is no large difference in the average brightness level between the area EA inside the photometric frame and the area EB outside the photometric frame, and it is almost uniform over the entire screen, that is, the preset threshold value is set. If TH1≤Ea-Eb≤TH2 with respect to the threshold levels TH1 and TH2, the discrimination circuit 15 sets the control signal C to L level and opens the analog switch SW in the photometry circuit 16.

As a result, the video signals respectively extracted by the gate circuits 7a and 7b and corresponding to the areas EA and EB inside and outside the photometric frame are integrated and averaged by the integrating circuits 17 and 18, respectively, and the resistors R ₁ and R _After being given a predetermined weight by ₂ (actually, the weight in the photometric frame is large)
20 is added, and the exposure control unit 2 is passed through the buffer amplifier 19.
An exposure control signal is supplied to. As a result, the exposure controller 2 is feedback-controlled on the basis of the average brightness level of the entire screen of the image pickup screen 100, and becomes the average photometry mode (however, the average photometry mode of the present invention is within and outside the frame relative to the photometry frame priority mode). Although the difference in weighting is reduced, in practice, the weighting in the photometric frame may be increased to set the focus within the frame).

Further, as shown in FIG. 3 (a), in the discrimination circuit 15, a backlight screen in which the average luminance level corresponding to the area Eb outside the photometric frame is higher than the average luminance level Ea corresponding to the area EA inside the photometric frame, and When it is determined that Ea-Eb <TH1, the control signal C becomes H level and the analog switch SW is closed.

As a result, the resistor R ₂ for weighting the luminance signal corresponding to the area EA in the photometric frame is further connected in parallel with the resistor R ₃ ,
The resistance value is smaller than that in the above-described full-screen average photometry, the voltage drop of the output of the integrating circuit 18 is small, and the weighting of the voltage addition to the photometry frame outside area EB of the signal in the photometry frame inside area EA is large, The brightness signal level of the area EA within the photometry frame is greatly prospered, and the weighted photometry mode within the photometry frame is set. Therefore, the exposure of the portion of the dark subject against the background is corrected, and so-called backlight correction is performed.

Further, as shown in FIG. 3B, in the discrimination circuit 15, the average luminance level Ea corresponding to the area EA inside the photometric frame is higher than the average luminance level Eb corresponding to the area EB outside the photometric frame, and When TH2 <Ea-Eb and so-called blown-out highlights occur, the control signal C becomes the H level and the analog switch SW is closed, as in the case of backlight compensation shown in FIG. The weighting of the signal corresponding to the inside of the inner area EA is increased, and the weighted metering mode in the metering frame is set. Therefore, the exposure of an object that has high-brightness overexposure against the background is corrected, and so-called overexposure correction can be performed.

As described above, when the brightness difference between the area inside and outside the photometric frame is within the predetermined range, the average photometry is performed regardless of the size relationship of the brightness level inside and outside the frame, and the exposure control is performed based on the average brightness level of almost the entire screen. Done.

If the brightness difference between the inside and outside of the metering frame is large and backlight compensation or overexposure compensation is required for the screen, priority metering within the metering frame is performed to focus the exposure compensation on the main subject and correct the unnatural screen. You can

Now, the exposure control means of the automatic exposure control device of the present invention is as described above, but as described at the beginning, according to the device of the present invention, the object or camera can be moved. Even if the subject moves from inside the metering frame to outside the frame, it has an automatic tracking function that detects the position of the subject from the brightness difference between the subject and the background and tracks the metering frame. If there is a brightness difference between the inner and outer areas EA, EB, the position where the metering frame 101 is located can be tracked by the object so that the brightness difference becomes larger, that is, the main object is captured within the metering frame 101. . As a result, regarding the backlight screen correction shown in FIG. 3A and the overexposed screen correction shown in FIG. 3B, even if the subject moves, a sudden unnatural screen change occurs in the exposure state. Natural correction can be performed without any Also, in the state where the brightness difference between the inner and outer areas EA and EB of the photometric frame becomes small and the tracking operation of the photometric frame cannot be performed, as shown in FIG. 3 (c), the screen also averages based on the average brightness level of the entire screen. Since it is in the photometric state,
It is not necessary for the metering frame to follow the subject.

At this time, the photometric frame may be held at the position immediately before the tracking operation is stopped, or may be forcibly moved to, for example, the initial position in the center of the screen, and can be appropriately selected according to its design. it can.

Next, a tracking algorithm by the control microcomputer 13 for automatically tracking the photometric frame 101 to the subject based on the brightness difference between the areas EA and EB inside and outside the photometric frame 101 will be described with reference to FIGS. 4 and 5. To do.

According to the present invention, since the unit change amount of the position change of the photometric frame 101 is set, as shown in FIG. 4, the photographing screen is divided into m × n blocks and set, and the upper, lower, left and right are set. The movement is controlled in 1-block units, and its control algorithm is set as follows.

 FIG. 5 (a) shows the flow chart.

When the tracking operation is started, the control microcomputer 13 checks the control signal C of the discrimination circuit 15 (step 1), and C
Is at the L level, it is determined that the brightness difference between the inside and outside of the photometric frame is small and tracking due to the brightness difference is difficult.
Is held at that position, or is returned to the initial position in the center of the screen, for example, and the process returns to step 1. If the control signal C is at the H level in step 1, it is determined that a sufficient brightness difference between the inside and outside of the photometric frame is obtained, and the position control operation of the photometric frame 101 is subsequently performed.

In step 3, the value of the output | Ea-Hb | of the absolute value circuit 11 is stored in the variable e1, and in step 4, the photometric frame 101 is shifted to the right by one block as seen in FIG. Then move to step 5 and set the variable e2 to the photometric frame 1
Output of absolute value circuit 11 at the position after 01 is moved | Ea-Eb |
Is stored, and the contents of e2 and e1 are compared in step 6. If e2> e1, it means that the brightness difference is increased by shifting the metering frame 101 to the right, and this is the same as the metering frame more accurately capturing the subject.
The process shifts to 8 and the light is measured at that position. Based on the result, the exposure control unit 2 is driven to stop the aperture, and the AGC circuit and the like are controlled to perform exposure control.

On the other hand, if e2> e1 is not found in step 6, move the photometry frame 101 to the left by 1
After shifting by block and returning to the mode position, step8
Then, the exposure control unit 2 is driven based on the result of photometry at that position to perform exposure control.

Then, in steps 9 to 14, the photometric frame 101 is shifted up one block on the shooting screen shown in FIG.
As in ep3 to step8, if the brightness difference between the inside and outside of the photometric frame increases, that position is measured, and if it does not increase, the photometering is performed by returning to the original position, and exposure control is performed.

Similarly, shift the photometric frame 101 one block to the left in steps 15 to 20 and shift the photometric frame 101 to one block down in steps 21 to 26, align the photometric frame to the position where the brightness difference increases and control the exposure. After performing, the process returns to step 1 and the above operation is repeated while the brightness difference is equal to or higher than a predetermined level.

In this way, if the brightness difference between the inside and outside of the photometric frame 101 is equal to or greater than the predetermined level, the photometric frame 101 can continue to be aligned with the subject even when the subject moves, and the video signal level in each photometric frame 101 is focused. Can be metered.

Although the photometric frame and the tracking frame are shared in the above-mentioned embodiment, they may be set separately, and there is no problem in achieving the present invention.

Also, in the flow chart of FIG. 5 (a), step
When screen discrimination is performed in step 1, step1 is performed so that malfunction does not occur due to excessive fluctuations in brightness difference inside and outside the photometric frame 101 and noise.
Steps 1-1 and 1-2 shown in Fig. 5 (b) are inserted between step 3 and step 3, and between step 1 and step 2, respectively, and the same mode continues for m field periods (for example, several field periods) or more. When the tracking mode is changed for the first time, and when the m-field is less than m field, a momentary noise is generated, and the mode is not changed, the stability is further increased.

Further, in the above-described embodiment, the case where the weighting in the photometry frame is changed in two steps at the time of overexposure correction and at the time of backlight correction in the exposure control has been described, but in the case of backlight at the time of FIG. For each of the overexposure corrections in FIG. 3B, as shown in FIG. 6, the values of Ea-Eb are set to TH1-1, TH1-2,
, TH1-n, TH2-1, TH2-2, ..., TH2-n are compared with n threshold values, and the correction amount of the photometric circuit is finely controlled in n steps according to the result. Good.

FIG. 7 shows the configuration of the photometric circuit 16 'in that case, and the same components as those in FIG. 1 are designated by the same reference numerals.

Resistor R ₂ for weighting the luminance signal of the area EA within the photometric frame
In addition, a series circuit of resistors and switches (R _3-1 , R _3-2 , ...,
R _3-n , SW ₂ , ..., SW _n ) are respectively connected in parallel. The value of each resistor may be appropriately set according to the degree of change in weighting and the design at that time.

The discriminating circuit 15 ′ for controlling the opening and closing of these switches SW ₁ , SW ₂ , ..., SW _n is provided by the Ea-Eb output from the subtraction circuit 10.
For the backlight correction (Ea-Eb <TH1) in FIG. 3 (a) and the overexposure correction (Ea-Eb> TH2) in FIG. 3 (b), the threshold levels TH1, TH1 respectively. -1, TH1-2,
..., TH1-n, TH2, TH2-1, TH2-2, ..., compared to the TH2-n and n steps, the corresponding control signal in the control signal C ₁ -C _n is the H level in accordance with the result , And controls the resistance connected in parallel with the resistance R ₂ . As a result, the weighting of the signal in the area within the photometric frame is controlled in n steps, and exposure control with high accuracy and high sensitivity becomes possible.

FIG. 8 shows another embodiment of the automatic exposure control apparatus of the present invention, focusing on the function of tracking a subject by the photometric frame 101, and adding a focus tracking function to a moving subject.

In FIG. 8, only parts different from those in FIG. 1 will be described. Reference numeral 21 denotes an automatic focus adjustment device, which is a motor 22 for moving the taking lens 1 to perform focus adjustment, and a photometric frame 101 inside the photometry frame 101 that has passed through the gate circuit 7a. Output of the band pass filter 23 that extracts high frequency components from the luminance signal corresponding to the area EA, the peak detection circuit 24 that detects and holds the peak of the output signal of the band pass filter 23 during one field period, and the peak detection circuit 24 Delay circuit that delays 1 field by 2
5.Compare the peak value of the current field output from the peak detection circuit 24 with the peak value of the previous field output via the delay circuit 25, and move the motor in the direction to cancel the displacement.
It is composed of a motor drive circuit 26 that drives 22 to move the taking lens.

With this configuration, the peak value of the high frequency component of the luminance signal corresponding to the area in the photometry frame 101 that also serves as the distance measurement frame is detected for each field, and the so-called hill climbing control is performed by driving the taking lens so that this peak value is maximized. I do.

As a result, it is possible to always keep the focus on the subject in the photometry frame 101 which is shared by the range-finding frame, and even when the subject moves, it can be tracked and always perform optimum exposure control and focus control. .

Also in this embodiment, the distance measuring frame, the photometric frame, and the tracking frame may be separately provided without being combined.

Further, in each of the above-described embodiments, when controlling the gate pulse generation circuit 14 based on a command from the control microcomputer 13, the size of the frame is increased so that the brightness difference between the areas EA and EB inside and outside the frame becomes large. Even if the size of the subject on the photographing screen changes, the subject can be accurately captured, and more appropriate exposure and focus control can be performed.

(Effects of the Invention) As described above, according to the automatic exposure control apparatus of the present invention, the photometry frame is provided in the screen, and whether the subject is subject to backlight compensation or luminance compensation inside and outside of the frame, or overexposure compensation is performed. Automatically determines whether or not is needed, and this metering frame is applied to a black subject during backlight compensation.
During whiteout correction, it is possible to track a white subject and perform exposure control so that optimum exposure is always achieved.

As a result, by always recognizing whether the subject in the screen is a black subject or a white subject, by tracking and controlling the exposure, even if the subject moves in the screen or changes from the backlit scene to the frontlit scene, The exposure is optimally controlled and a natural image can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an automatic exposure control device according to the present invention, FIG. 2 is a diagram showing areas inside and outside a photometric frame on a photographing screen, and FIG. 3 is a diagram showing different states of the photographing screen, FIG. 4 is a diagram of a photographing screen for explaining the tracking operation of the photometric frame, FIG. 5 is a flow chart for explaining the tracking operation, and FIG. 6 is another embodiment of the photometric circuit of the present invention. FIG. 7 is a block diagram showing another embodiment of the photometric circuit of the present invention, and FIG. 8 is a block diagram showing an embodiment in which the automatic exposure control device of the present invention is combined with an automatic focusing device. 9 and 10 are block diagrams showing a conventional automatic exposure control circuit. 6 …… Metering frame setting circuit 7a, 7b …… Gate circuit 10 …… Subtraction circuit 13 …… (for setting the metering frame) Controlling microcomputer 15 …… (Screen mode) discrimination circuit 16 …… Metering circuit 21 …… Automatic focus adjustment circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroshi Suda, Hiroshi Suda, 770 Shimonoge, Takatsu-ku, Kawasaki-shi, Kanagawa Canon Inc., Tamagawa Plant (72) Kunihiko Yamada, 770, Shimonoge, Takatsu-ku, Kawasaki, Kanagawa Canon Inc. In-house (72) Inventor Katsuji Yoshimura, 770 Shimonoge, Takatsu-ku, Kawasaki-shi, Kanagawa Canon Inc. Tamagawa Plant (56) References JP-A-56-119820 (JP, A) JP-A-62-203486 (JP, A) ) JP-A-63-254871 (JP, A)

Claims (1)

(57) [Claims] 1. A photometric frame setting means capable of moving a set position of a photometric frame for intensive photometry on a subject within a photographing screen, and brightness levels corresponding to inside and outside of the photometry frame are respectively detected, and the brightness levels thereof are detected. Discriminating means for discriminating whether or not the difference is equal to or more than a predetermined threshold value, and controlling the exposure state based on the discrimination result of the discriminating means, and the difference between the brightness levels inside and outside the photometric frame exceeds the threshold value. In this case, the weighting for the brightness level corresponding to the inside of the photometric frame is increased to perform the priority photometry for the brightness level inside the photometric frame, and the difference between the brightness levels inside and outside the photometric frame is the threshold value. In the case of the following, the exposure control means for performing average photometry of the brightness levels inside and outside the photometric frame, and operating the exposure control means, in order to track the set position of the photometric frame to the movement of the subject image. A photometric frame tracking means for controlling the photometric frame setting means, and a change in the exposure state due to the movement of the set position of the photometric frame by the photometric frame tracking means, so that the exposure control means can correct it in parallel. The automatic exposure control device characterized in that