JPH06121225A - Electronic still camera and its control method - Google Patents

Abstract

PURPOSE:To correct deterioration in picture quality due to deficient exposure due deficient luminous quantity of main light emission at image pickup when preliminary light emission is made by a strobo to prevent a pink-eye effect. CONSTITUTION:A distance up to an object is measured by a range finder sensor 27. When preliminary light emission is set by a preliminary light emission switch 24, a gain control and blanking circuit 12 are controlled so that the greater the distance up to an object is, the higher the amplification factor of the video signal becomes. A video signal representing an object is given to the gain control and blanking circuit via circuits 7, 8, 9, 10 and 11, and when preliminary light emission is set, the video signal is amplified in response to a distance up to the object and the result is recorded in a memory card.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic still camera capable of photographing an object using a stroboscopic light emitting device and a control method thereof.

[0002]

[Background Art] When a subject is photographed using a stroboscopic light emitting device, if the eyes are dark enough to open, the stroboscopic light illuminates the human eye to photograph the blood vessels of the retina of the eye, and the eye is photographed red. The so-called red-eye phenomenon occurs. In order to prevent the red-eye phenomenon, there is also a stroboscopic light emitting device that pre-flashes the subject and narrows the pupil before shooting.

However, the amount of light that can squeeze the pupil is required in the pre-emission, and if one capacitor is used for both the pre-emission and the main emission for photographing a subject, the light amount becomes insufficient during the main emission, resulting in insufficient exposure. Become.

It is conceivable to provide a strobe light emitting device with a capacitor used for pre-emission and a capacitor used for main light emission in order to prevent a shortage of the amount of light at the time of main light emission, but miniaturization of the strobe light emitting device cannot be achieved.

[0005]

DISCLOSURE OF THE INVENTION It is an object of the present invention to prevent deterioration of image quality due to insufficient exposure even when pre-emission and main emission are performed by one capacitor.

The electronic still camera of the present invention is a distance measuring means for measuring a distance to a subject, a photographing means for photographing the subject and outputting a video signal representing the subject, and a stroboscopic light emitting device before photographing by the photographing means. Strobe light emitting device control means for controlling the strobe light emitting device so that the stroboscopic light is projected to the subject by projecting the stroboscopic light to the subject, and the main flash is projected to the subject after a predetermined time has elapsed from the prefiring. Shooting control means for controlling the shooting means to shoot a subject in synchronism with the above, an amplifier circuit for variably amplifying the level of the video signal output from the shooting means, and a subject measured by the distance measuring means Is greater than or equal to the distance at which underexposure is caused by the amount of the main light emission, the amplifier circuit according to the measured distance. Raising the amplification factor, characterized in that it comprises an amplifier circuit control means for controlling to amplify greater level of the video signal outputted from the image pickup means.

Further, according to the present invention, in an electronic still camera for photographing a subject and recording a video signal representing the subject on a recording medium, the distance to the subject is measured, and before photographing,
Pre-flash is used to project the strobe light to the subject, and after a certain time has passed from the pre-flash, the strobe light device is used to perform main flash and the strobe light is projected to the subject to shoot the subject. When the measured distance to the subject is equal to or more than the distance at which the light amount of the main light emission causes underexposure, the amplification factor may be increased according to the measured distance to further amplify the video signal level. Characterize.

Before shooting, the flash light emitting device is used for pre-flashing and the flash light is projected onto the subject.
The so-called red eye phenomenon is prevented. Due to the pre-flash, the capacitor of the stroboscopic light emitting device is insufficiently charged, and the capacity at the time of main flashing is insufficient. However, according to the present invention, when the subject is far enough to cause insufficient exposure due to the insufficient capacity of the capacitor, the amplification factor depends on the distance to the subject. Raised, the level of the video signal representing the subject is greatly amplified. Therefore, the deterioration of image quality due to insufficient exposure is corrected. Pre-light emission and main light emission can be dealt with by one capacitor having a not so large capacity, and the stroboscopic light emitting device can be downsized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment in which the present invention is applied to a digital still camera will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram of a digital circuit of an embodiment of the present invention.
It is a block diagram which shows the electric constitution of a still camera.

The imaging optical system includes a diaphragm 2, an imaging lens 3,
And a CCD 4 as a solid-state electronic image sensor (image sensor). A mechanical shutter is provided if necessary, but generally the shutter function is achieved by an electronic shutter realized by the control of the CCD 4. The image pickup lens 3 forms a subject image on the CCD 4,
It is moved by the imaging lens driving device 25 controlled by the CPU 5 and positioned at the in-focus position.

The digital still camera is provided with a power switch 21 and a shutter release button 22, and a signal indicating the input of the power switch 21 and the depression of the shutter release button 22 is given to the CPU 5. Shutter release button 22 has a two-step stroke
This type is used for photometry and distance measurement in the first step of pressing, and the main shooting of the subject is performed in the second step of pressing.

The digital still camera is provided with a flash photographing setting switch 23 and a pre-flash setting switch 24, and signals indicating the settings of the respective switches are given to the CPU 5. Depending on the setting of the strobe photographing setting switch 23, strobe photographing is performed by a strobe device described later. Depending on the setting of the pre-flash setting switch 24, pre-flash is performed immediately before the main flash of the strobe device at the time of shooting. When the subject is a human being, the pupil is squeezed by the pre-emission, so that a so-called red-eye phenomenon is prevented.

The digital still camera is provided with a photometric sensor 26 for preliminary photometry, and photometric data is given to the CPU 5. The CPU 5 controls at least one of the aperture value and the shutter speed on the basis of the photometric data obtained from the photometric sensor 26 so that the exposure amount to the CCD 4 falls within an appropriate range.

After the approximate exposure amount adjustment based on such preliminary photometry, preliminary photographing is performed. By this preliminary photography, the photometric value is calculated and the precise exposure control is performed using the video signal obtained from the CCD 4. These high precision exposure controls will be described in detail later.

The digital still camera is provided with a distance measuring sensor 27 for distance measurement, and distance measuring data representing the distance to the object is given to the CPU 5. CPU5
Also, the imaging lens 3 is positioned at the in-focus position via the imaging lens driving device 25 based on the distance measurement data from the distance measurement sensor 27. The CPU 5 further determines the amount of light emitted from the strobe device based on the distance to the subject and the aperture value, as will be described later.

The digital still camera is for indoor photography,
As will be described later, a strobe device is included so that an appropriate exposure amount can be obtained when auxiliary light is required. The digital still camera can be set to prohibit flash photography. When flash photography is prohibited, flash photography is not performed. When flash photography is not prohibited and the subject is dark, or flash setting switch 23 is set. The strobe device is driven by the power supply 41 during the operation.

The strobe device is a discharge tube (strobe) 45
And a charging circuit 40 for charging the electric charge given to the discharge tube 45.
And a light emission quantity control circuit 30 for controlling the quantity of strobe light emission, and a stop circuit 46 for stopping the light emission of the discharge tube 45.

The charging circuit 40 includes a prohibiting circuit 47 for prohibiting the accumulation of charges in the main capacitor 43. This prohibiting circuit 47 is controlled by the charge prohibiting control signal output from the CPU 5, and while the charge prohibiting control signal is off, the switch included in the charge prohibiting circuit 47 is turned off and the charge is accumulated in the main capacitor 43. Is prohibited. The inhibit circuit 47 is turned on when the shutter release button 22 is not pressed.

When the charge prohibiting circuit 47 is switched on, the voltage of the power supply 41 is boosted by the boosting circuit 42,
The main capacitor 43 is charged. The charging voltage of the main capacitor 43 is supplied to the CPU 5 through an appropriate voltage reducing circuit or voltage detecting circuit.
It is detected by being applied to the A / D port of the. This allows the CPU 5 to know that charging of the main capacitor 43 has been completed.

Since the CPU 5 can detect the charging voltage of the main capacitor 43, the charging voltage of the main capacitor 43 before the discharge tube 45 emits light and the main capacitor 43 after the discharge tube 45 emits light.
It is also possible to detect each of the charging voltage and the charging voltage and to calculate the amount of light emitted from the discharge tube 45 from the difference between these voltages.

The strobe light emission is performed by giving a strobe light emission command X ON to the trigger circuit 44. When the strobe light emission command X ON from the CPU 5 is given to the trigger circuit 44, the trigger circuit 44 is driven, the electric charge accumulated in the main capacitor 43 is discharged through the discharge tube 45, and strobe light emission starts.

The amount of strobe light emission is determined according to the distance to the subject. The CPU 5 creates emission light amount data (EVR value) so that the flash emission light amount is determined according to the distance to the subject. The emitted light amount control circuit 30 includes an electronic volume circuit (EVR) 31 including a D / A converter 31A, and emitted light amount data output from the CPU 5 is given to the EVR 31 and converted into a voltage for output. . Also included is a differential amplifier circuit 36 for providing a stop signal to stop circuit 46.

Further, the reference light source 32 is provided in the light emission quantity control circuit 30.
And a capacitor 34 is included. The output voltage of the EVR 31 is given to the capacitor 34 via the resistor 33. A switch 35 for discharging the charge of the capacitor 34 is also provided. A reference power supply circuit is provided at the negative input terminal of the differential amplifier circuit 36.
The reference voltage output from 32 is applied, and the differential amplifier circuit 36
The terminal voltage of the capacitor 34 is applied to the positive input terminal of the.

The switch 35 is normally turned on, and CP
It is turned off when the flash emission command X of U5 is given. When the switch 35 is turned off, the EV
Charging of the capacitor 34 is started based on the voltage output from R31.

A voltage is output from the EVR31 and the switch 35
When is turned on, a predetermined charge is accumulated in the capacitor 34. When the terminal voltage of the capacitor 34 becomes equal to the reference voltage output from the reference power supply 32, a stop signal is output from the differential amplifier circuit 36 and is given to the stop circuit 46, so that the discharge tube 45 stops emitting light.

In the CCD 4, interlace shooting is performed by the substrate extraction pulse, the A field vertical transfer pulse, the B field vertical transfer pulse and the horizontal transfer pulse, and the A field and B field video signals (GRG) are obtained.
B color sequential signals) are alternately generated for each field period and sequentially read. The driving of the CCD 4 (imaging and reading of a video signal) is performed at least at the time of photographing, and for precision photometric processing and distance measuring processing prior thereto.

The video signals of the A field and the B field representing the subject image output from the CCD 4 are passed through a correlated double sampling circuit (CDS) 7 to a color separation circuit 8
Given to three primary colors, G (green), R (red) and B
It is separated into (blue) color signals.

The color signals G, R and B are applied to a variable gain amplifier circuit (hereinafter referred to as GCA) 9. In Figure 1, GC
Although one block is shown as A9, GCA is actually provided for each of the R, G, and B signals. In this GCA 9, correction of variations in light transmittance between colors of color filters provided in the CCD 4 (hereinafter referred to as color filter variation correction) and white balance adjustment are performed.

The output color signals R, G, B of the GCA 9 are gradation-corrected by the gamma correction circuit 10 and input to the clamp and resampling circuit 11.

The clamp and resampling circuit 11 is
The three color signals R, G, B are clamped and re-converted into color sequential signals of GRGB ... Which match the color filter arrangement in the CCD 4. This color sequential signal is input to the gain control and blanking circuit 12.

The gain control and blanking circuit 12 can change the amplification factor under the control of the CPU 5. As shown in FIG. 4, the gain control and blanking circuit 12 is set to have a larger amplification factor as the distance to the subject increases. For example, when the distance to the subject is 1.5 m, the gain does not change, but when the distance to the subject is 2.1 m, the gain is double, and when the distance to the subject is 2.6 m, the gain is 3 m. When the distance to the subject is 3.0 m, the amplification factor is set to 4 times.

The gain control and blanking circuit 12 adds a blanking signal to the color sequential signal. The output signal of the gain control / blanking circuit 12 is applied to the A / D converter 14 to be digitally converted.

Before the main photographing, the precise photometric processing (exposure control) is performed as described above. The photometric processing is performed by utilizing the low frequency component of the video signal obtained from the CCD 4 by the preliminary photographing.

In order to take out the low frequency component of the video signal representing the image in the photometric area (described later) provided in the photographing area of the CCD 4 for the photometric processing, the Y _L synthesizing circuit 15,
A gate circuit 16, an integrating circuit 17, an amplifying circuit 18, and an A / D converter 19 are provided. The output data of the A / D converter 19 is given to the CPU 5.

The main photographing is performed after the photometric processing, the exposure control (control of the diaphragm and the shutter) based thereon, and the focusing control (positioning of the image pickup lens 3). CC by actual shooting
The video signals obtained from D4 are the above-mentioned circuits 7, 8, 9,
Input to A / D converter 14 via 10, 11 and 12
The data is converted into digital image data by the / D converter 14, processed by an image data processing circuit (not shown) such as Y / C separation and data compression, and then recorded on a recording medium such as a memory card. become.

The photometric processing (and exposure control based on it) prior to the main photographing will be described.

The photometric processing is performed by the Y _L combining circuit 15, as described above.
This is performed using the gate circuit 16, the integrating circuit 17, and the amplifying circuit 18. The Y _L synthesizing circuit 15 is supplied with the output color signals R, G, B of the GCA 9.

The CPU 3 outputs a window signal WIND1 for controlling the gate circuit 16 and a reset signal HLRST1 for resetting the integrating circuit 17. These signals WI
The timing of ND1 and HLRST1 will be described later.

The color signals R, G and B output from the GCA 9 are added by the Y _L synthesizing circuit 15 to generate a relatively low frequency luminance signal Y _L (hereinafter simply referred to as luminance signal Y _L ). The luminance signal Y _L passes through the gate circuit 16 while the window signal WIND1 is applied during the required horizontal scanning period. The integrator circuit 17 has a reset signal HLRS.
It is reset when T1 is given, and then the luminance signal Y _L input from the gate circuit 16 is integrated. Integrator circuit 17
The integrated signal of is amplified by the amplifier circuit 18 and then A / D converter
It is input to 14, is converted into digital integration data for photometry by this A / D converter 14, and is taken in by the CPU 5.

In the photometric processing of this embodiment, average photometry (hereinafter referred to as A
V metering) and spot metering (hereinafter referred to as SP metering) for measuring the brightness of the main subject in the field of view. The SP metering is useful when the brightness of the main subject and the background in the field of view are different and it is necessary to set an appropriate exposure condition accordingly.

Further, in this embodiment, the integration by the integration circuit 17 and the A / D conversion operation and the addition processing by the A / D converter 14 are alternately performed every horizontal scanning period.

FIG. 2 shows the AV photometric area and the SP photometric area set in the photographing area 50 of the CCD 4.

The AV photometric area is basically set over almost the entire photographing area 50. In this embodiment, the AV photometric area is set for a period of 40 μs after the lapse of 16 μs from the trailing edge of the horizontal synchronizing signal HD (the start point of the horizontal scanning period) in the horizontal direction, and the 35th horizontal scanning in the vertical direction. 24th from the line
It is set up to the 6th horizontal scan line.

The SP photometric area is set as a small area at an arbitrary position within the photographing area 50. In this embodiment, the SP metering area is set at the center of the photographing area 50, and the horizontal direction is the 87th horizontal scanning line in the vertical direction during the period of 15 μs after 28.5 μs has elapsed from the fall of the horizontal synchronizing signal HD. From the 194th
It is set up to the second horizontal scan line.

The memory associated with the CPU 5 is provided with a photometry area and a distance measurement area. AV metering area data area and SP metering area data
There is an area.

When AV photometry is performed, integration is performed every other horizontal scanning line in the AV photometry area.
The above integration is performed every other horizontal scanning line for A / D conversion, reset and integration of the integration circuit, and data addition processing.

As shown in FIG. 3, in AV photometry, between the 34th horizontal scanning line and the 246th horizontal scanning line, the gate circuit 16 is provided with 16 μs after the fall of the horizontal synchronizing signal HD. A window signal WIND1 having a pulse width of 40 μs is applied. Then, the integrating circuit 17
Integration of the luminance signal Y _L , A / D conversion of the integration signal in the horizontal scanning period subsequent to the horizontal scanning period in which this integration operation is performed, reset of the integration circuit 17 and AV of the memory.
The addition of integrated data to the photometric area data area is alternately repeated for each horizontal scanning period.

When SP photometry is performed, a pulse width rises 28.5 μs after the fall of the horizontal synchronizing signal HD in the gate circuit 16 between the 87th horizontal scanning line and the 194th horizontal scanning line. A window signal WIND1 of 15 μs is provided.

Also in SP photometry, when the window signal WIND1 having a pulse width of 15 μs is given to the integrating circuit 17 and the luminance signal Y _L is integrated, the integration is performed in the horizontal scanning period next to the horizontal scanning period in which the integration operation is performed. A / D conversion of the signal, reset of the integrating circuit 17, and addition of the integrated data to the SP photometric area data area of the memory are performed.

When AV photometry is performed, the CPU 5 adds integrated data for one horizontal scanning line obtained based on the window signal WIND1 having a pulse width of 40 μs in the AV photometry area data area for one field period by the procedure described later. Then, the AV photometric value is calculated.

When SP metering is performed, the CPU 5
The integrated data for one horizontal scanning line obtained based on the window signal WIND1 having a pulse width of 15 μs is added in the SP metering area data area for one field period by the procedure described later to calculate the SP metering value.

In this digital still camera, focusing control is performed based on the distance measurement data from the distance measurement sensor 27. The lens driving device 25 is driven based on the distance information to the subject obtained from the distance measurement data, and is positioned at the in-focus position.

In general, when the image is out of focus and blurred, the high frequency component contained in the video signal obtained from the CCD by photographing is small. When the image comes into focus, the high-frequency component of the video signal increases, and the high-frequency component contained in the video signal becomes maximum at the correctly focused position. Focusing control can also be performed based on such a fact.

In this case, a gate circuit for passing the output signal of the gain control and blanking circuit 12 for a certain period, a bandpass filter for extracting high frequency components, a detection circuit, an integration circuit and an amplification circuit are provided. Then, distance measurement data is calculated, and focusing control is performed based on this data.

FIG. 4 shows the relationship between the distance to the subject and the degree of amplification of the gain control and blanking circuit 12 according to the distance. FIG. 5 shows the relationship between the aperture value (FNo.) According to the distance to the subject and the guide number GNo. That indicates the amount of light emitted from the strobe light emitting device.
Is the guide number GNo. And the light emission amount data EVR value and E
The corresponding relationship with the output voltage of VR31 is shown.
Various data shown in FIGS. 4 to 6 are stored in the memory of the CPU 5.

FIG. 7 is a flow chart showing the procedure of photographing.

When the power switch 21 of the digital still camera is turned on, it is checked whether or not the flash photography prohibition mode is set (step 61). If the flash photography prohibit mode is not set (step 61)
NO), a charge permission signal is output from the CPU 5, the switch of the charge inhibition circuit 47 is turned on, and the main capacitor 43 is charged (step 62). If the flash photography prohibition mode is set (YES in step 61), the CPU
No charge permission signal is output from 5 and the main capacitor 43 is not sufficiently supplied (step 63).

When the shutter release button 22 is pressed in the first step (YES in step 64), the output of the charge permission signal output from the CPU 5 is stopped. As a result, the switch of the charge prohibition circuit 47 is turned off, and the charging of the main capacitor 43 is prohibited (step 65).

Further, the first shutter release button 22
When the step is pushed down, the distance measuring sensor 27 measures the distance to the subject (step 66) and the photometric sensor 26.
Preliminary photometry by and the photometry by circuits 15, 16, 17 and 18 are performed (step 67). The lens driving device 25 is driven according to the distance to the subject, and the imaging lens 3 is positioned at the in-focus position (step 68).

When the shutter release button 22 is pressed in the second step (YES in step 69), it is determined whether or not the flash photography is performed according to the photometric value and the setting status of the flash photography prohibition mode. (Step 70).

If the flash photography prohibition mode is set, or if the photometry value is such that flash photography is unnecessary, the subject is photographed without firing the flash (NO in step 70, 71).

When the flash photography prohibition mode is not set, and the flash photography setting switch 23 is set, or the photometric value is low enough to require flash photography, the process shifts to the flash photography (step 70). Then YES).

If the pre-emission mode is set by the pre-emission setting switch 24 to prevent the so-called red-eye phenomenon (YES in step 72), whether the distance to the object measured by the distance measuring sensor 27 is 1.5 m or more. It is judged (step 73). If the pre-flash is performed when the distance to the subject is 1.5 m or more, the amount of emitted light may be insufficient during the main flash for shooting the subject.
For this reason, referring to FIG. 4, the gain control and blanking circuit 12 is set to have a higher amplification factor as the distance to the subject increases (step 74).

Subsequently, from the aperture value and guide number GNo. Calculation table shown in FIG. 5 stored in the memory of the CPU 5, the aperture value and the guide number are determined according to the distance to the subject (step 75). ). The diaphragm 2 is driven so that the diaphragm value becomes a predetermined diaphragm value (step
76). Further referring to FIG. 5, the EVR value is calculated from the determined guide number GNo.

When the pre-flash mode is set by the pre-flash setting switch 24 (YES in step 77), an ON signal is output from the CPU 5 immediately before the subject is photographed and pre-flash is performed by the strobe light emitting device (step 7).
8). After the pre-flash is fired, the main flash is fired by the strobe light-emitting device for shooting the subject (step
79).

If the pre-emission mode is not set by the pre-emission setting switch 24 (NO in step 77), the main emission is performed without the pre-emission (step 7).
9).

When the main light emission is performed, the shutter control in the CCD 4 is performed and the subject is photographed. (Step
80).

In the main light emission, the EVR value determined based on FIGS. 5 and 6 is used as the emitted light amount data by the CPU.
It is output from 5 and given to EVR31. D / A converter 31
The voltage is converted into an analog voltage value at A, and the strobe light is stopped by the stop circuit 46 according to the magnitude of the analog voltage value (step 81).

When the photographing of the subject is completed, the video signal is read from the CCD 4 (step 82) and the circuits 7, 8, 9
Recording on the memory card is performed via steps 10, 11, 12 and 14 (step 83). It goes without saying that the video signal is amplified in the gain control and blanking circuit 12 by the amplification factor according to the setting of the pre-light emission mode and the distance to the subject.

When the processing of the video signal in each circuit is completed, the diaphragm 2 returns to the home position, and the gain control and blanking circuit 12 gain is also set to a predetermined value (steps 84 and 85).

When the photographer releases his / her finger from the shutter release button 22, the photographing process ends (step 8).
6).

In the above-described embodiment, the embodiment in which the present invention is applied to the digital still camera has been described, but the present invention is not limited to the digital still camera, but can be applied to a still camera for recording on a magnetic disk.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a digital still camera.

FIG. 2 shows a photometric area.

FIG. 3 is a time chart when photometry is performed.

FIG. 4 shows a relationship between a distance to a subject and an amplification factor changed according to the distance.

FIG. 5 is a table for calculating an aperture value and a guide number from a distance to a subject.

FIG. 6 shows a correspondence relationship between a guide number and an EVR value.

FIG. 7 is a flowchart showing a processing procedure of photographing.

[Explanation of symbols]

 5 CPU 12 Gain control and blanking circuit 23 Strobe setting switch 24 Pre-flash setting switch 27 Distance measuring sensor 30 Emission light intensity control circuit 40 Charging circuit 45 Strobe

Front page continuation (72) Inventor Hiroshi Shimatani 3-11-46 Izumisui, Asaka-shi, Saitama Prefecture Fujisha Makoto Film Co., Ltd. (72) Izumi Izumi 3-11-46 Izumisui, Asaka-shi, Saitama Prefecture Within Film Co., Ltd.

Claims (2)

[Claims] 1. A distance measuring means for measuring a distance to a subject, a photographing means for photographing the subject and outputting a video signal representing the subject, and a pre-flash by a stroboscopic light emitting device before photographing by the photographing means. Strobe light emitting device control means for projecting strobe light onto the subject, and performing main light emission after a predetermined time has elapsed from the pre-light emission to control the strobe light emitting device so that the strobe light is projected onto a subject, and the photographing means synchronized with the main light emission. Shooting control means for controlling to shoot a subject by means of an amplifier circuit for variably amplifying the level of a video signal output from the shooting means, and the distance to the subject measured by the distance measuring means is the main light emission. When the amount of light is equal to or more than the distance at which exposure is insufficient, the amplification factor of the amplification circuit is increased according to the measured distance, and the imaging means Electronic still camera provided with an amplifier circuit control means, for controlling to amplify greater level of the video signal al outputted. 2. An electronic still camera that photographs a subject and records a video signal representing the subject on a recording medium, measures the distance to the subject, and performs pre-flashing using a strobe light emitting device before photographing. After a certain period of time has passed from the pre-flash, the main flash is used to shoot the subject by shooting the strobe light on the subject, and the measured distance is the distance to the subject. A control method for an electronic still camera, which increases the amplification factor according to the measured distance and further amplifies the level of the above video signal when the amount of light emitted is equal to or more than the distance at which exposure is insufficient.