JPH0961911A - Camera system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a photographer to recognize an insufficient light control state by executing a zooming action to a wide side before the main emission of light is executed after the pre-emission thereof is executed on a telephoto side. SOLUTION: This camera system is constituted so that a photometry is executed by making stroboscopes 19 and 20 whose irradiation areas are varied execute the pre-emission of light before the main emission thereof and the control value of a main light emitting time is calculated base on the photometry result. This camera is also provided with an irradiation area detection means 215 detecting the irradiation area of the stroboscope 19 and 20, an upper limit value arithmetic means 200 calculating the upper limit value of the light emission based on the detected result of the detection means 215 and a decision means 200 deciding whether a light control can be executed by the main emission of light before the main emission of light or not based on necessary emitted light quantity and the upper limit value of the light emission calculated by decision means 200 before the pre-emission of light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera system in which pre-flash photometry is performed before main light emission at the time of shooting to calculate an appropriate control value for the main light emission. The present invention relates to a camera system in which is variable.

[0002]

2. Description of the Related Art Conventionally, as a camera system for judging whether proper exposure of an object is possible or not before main light emission based on a result of photometry by pre-light emission, pre-light emission by invisible light is performed and a correct strobe is obtained based on the reflected light. When exposure is expected, a predetermined mark is turned on to display a dimmable display, and when improper exposure is expected, the mark is blinked to display a warning.

Also, for example, Japanese Patent Laid-Open No. 61-156239.
JP-A-61-156240 and Japanese Patent Laid-Open No. 61-156240 disclose a control value of main light emission at the time of photographing as a relative amount of the received light by performing pre-emission of light on the subject prior to photographing and receiving reflected light from the subject. There has been proposed a camera system that can obtain an appropriate main light emission amount by stopping the light emission when the actual light emission amount of the main light emission reaches the specified light emission amount.

By the way, a camera system having a strobe uses an auto-zoom strobe capable of changing the irradiation area by automatically changing the irradiation angle of the strobe according to the focal length (zoom) of the photographing lens. Therefore, such an auto zoom strobe is often used in a camera system that performs pre-flash and main flash.

[0005]

However, in a zoom strobe, the guide number is generally high on the tele side because the emission angle is narrowed, and the guide number is low on the wide side because the emission angle is widened. Therefore, in a camera system having an auto-zoom strobe, for example, when pre-flashing is performed on the telephoto side and zooming to the wide side is performed before main flashing, the guide number decreases and dimming becomes insufficient. There is a risk. Nevertheless, the photographer has no way of knowing such lack of light control until the photograph is developed and the photograph is completed.

Further, for example, even if the dimming cannot be performed as a result of pre-light emission on the wide side, the guide number may be increased and dimming may be possible by zooming to the tele side. This also cannot be recognized by the photographer.

Similarly, although pre-flashing was not possible as a result of pre-flashing on the wide side, when dimming is possible by subsequent zooming to the tele side, a low guide number during pre-flashing (that is, If the main light emission is performed within a limit of (light emission upper limit value), the main light emission clearly causes the light amount to be insufficient, and the light emission energy of the strobe is wasted.

Therefore, a first object of the present invention is to determine whether or not dimming is possible in accordance with a change in guide number associated with a change in stroboscopic irradiation area after pre-flashing until main flashing. It is an object of the present invention to provide an efficient and easy-to-use camera system that can effectively utilize the light emission energy of the.

A second object of the present invention is to provide a highly reliable camera system free from dimming determination errors due to differences in film reflectance.

A third object of the present invention is to provide a camera system capable of confirming the dimmable range before stroboscopic photography.

[0011]

In order to achieve the above-mentioned object, in the first invention of the present application, the strobe whose irradiation area is variable is pre-flashed before the main flash, and the photometry is performed. In a camera system that calculates a control value at the time of main light emission based on an irradiation area detection unit that detects an irradiation area of a strobe, and an upper limit value calculation unit that calculates a light emission upper limit value based on the detection result of the irradiation area detection unit. A determining unit that determines whether or not dimming by main light emission is performed before main light emission based on the control value and the light emission upper limit value calculated by the upper limit value calculating unit after the pre-light emission.

That is, for example, at each time point after the pre-flashing and before the main flashing, the strobe irradiation area is detected to determine whether or not the dimming is possible. If the light cannot be dimmed or if it was not possible during the pre-flash, but it becomes possible due to zooming to the tele side after that, display these before shooting (main flash). I try to make it clear to the photographer.

In the first aspect of the invention, after the pre-emission, the main emission is controlled based on the emission upper limit value increased by the zooming to the tele side, thereby preventing the main emission from being insufficient in emission amount. It enables effective use of luminescence energy and efficient shooting.

It should be noted that the upper limit calculation means calculates the upper limit of light emission at the time of detecting the irradiation region by using the upper limit of light emission set according to the irradiation region of the strobe and the upper limit of light emission at the time of pre-light emission. Is desirable.

Further, when the display means for displaying the judgment result of the judgment means is provided, the judgment result is displayed by lighting and blinking the display element such as a mark or by displaying the difference between the control value and the light emission upper limit value. Is desirable.

In the second invention of the present application, the display means includes:
Even after the main light emission, the determination result of the determination means is displayed. That is, it is possible to check whether or not the light control has been appropriately performed without being affected by the reflectance of the film, after photographing.

Further, according to the third invention of the present application, a camera system for pre-flashing a strobe whose irradiation area is variable before main flashing to perform photometry and calculating a control value at the time of main flashing based on the photometry result. In the above, an irradiation area detecting means for detecting an irradiation area of the strobe and a dimming range calculating means for calculating a dimmable range by the main light emission based on a detection result of the irradiation area detecting means are provided before the main light emission. There is.

That is, the strobe irradiation area is detected at each time point after the pre-flash and before the main flash, and the dimmable range is calculated and displayed. If the subject is within the dimmable range due to zooming to the side or at the time of pre-flashing, the subject is outside the dimmable range due to subsequent widening. In this case, it is possible to clearly inform the photographer of these before photographing.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 is a cross-sectional view illustrating an optical configuration and the like when a camera system according to a first embodiment of the present invention is applied to a single-lens reflex camera. In this figure, reference numeral 1 denotes a camera body, in which optical parts, mechanical parts, electric circuits, films and the like are housed so that a picture can be taken.

Numeral 2 is a main mirror, which is slanted or retreated to the optical path of the photographing depending on the observation state and the photographing state. Further, the main mirror 2 is a half mirror, and even when the main mirror 2 is obliquely installed in the photographing optical path, approximately half of the light rays from the subject are transmitted to the focus detection optical system described later.

Reference numeral 3 is a focusing plate arranged on the planned image forming planes of the taking lenses 12 to 14, 4 is a pentaprism for changing the finder optical path, and 5 is a finder. The photographer can observe the photographing screen by observing the focusing plate 3 through the finder 5.

Reference numerals 6 and 7 denote an image-forming lens and a photometric sensor provided for measuring the brightness of an object on the observation screen. The image-forming lens 6 is provided with a focusing plate 3 and a photometric sensor via a reflection optical path in the penta roof prism 4. 7 is related to conjugation.
Reference numeral 8 is a shutter, and 9 is a photosensitive member made of a silver salt film or the like.

Reference numeral 25 is a sub-mirror which bends the light beam from the subject downward and guides it toward the focus detection unit 26. In the focus detection unit 26, the secondary imaging mirror 27, the secondary imaging lens 28, the focus detection line sensor 2
9 and the like are provided. A focus detection optical system is configured by the secondary imaging mirror 27 and the secondary imaging lens 28, and the secondary imaging plane of the photographing optical system is used as the focus detection line sensor 2.
It is tied on 9. The focus detection unit 26 detects the focus state of the subject in the photographic screen by a known phase difference detection method by processing of an electric circuit described later, and automatically controls the focus adjustment mechanism of the photographic lens.

Reference numeral 10 is a mount contact group that serves as an interface between the camera and the lens, and 11 is a lens barrel mounted on the camera body. 12 to 14 are photographing lenses, and 12 is a first group lens. This 1 group lens 1
2 can adjust the focus position of the photographing screen by moving back and forth on the optical axis. Reference numeral 13 denotes a second lens group, and the second lens group 13 can change the focal length of the photographing lens by changing the magnification of the photographing screen by moving left and right on the optical axis. The position (that is, the focal length) of the second lens group 13 is detected by the lens zoom position detection encoder 33 shown in FIG.

Reference numeral 14 is a third group fixed lens. Reference numeral 15 is a photographic lens diaphragm.

Reference numeral 16 denotes a first-group lens drive motor, which moves the first-group lens 12 back and forth in accordance with the automatic focus adjustment operation to automatically adjust the focus position. Reference numeral 17 denotes a lens aperture drive motor, which can be driven to drive the taking lens aperture to a desired aperture diameter.

Reference numeral 18 denotes an external strobe, which is attached to the camera body 1 and controls light emission according to a signal from the camera. Reference numeral 19 denotes a xenon tube, which converts current energy into luminescence energy. Reference numerals 20 and 21 are a reflection plate and a Fresnel lens, each having a role of efficiently condensing emission energy toward a subject. Reference numeral 22 denotes a group of flash contacts serving as an interface between the camera body 1 and the external flash 18. Reference numeral 30 denotes a glass fiber, which guides the light emitted from the xenon tube 19 to a light receiving element 31 such as a photodiode for monitoring the light.
The light receiving element 31 directly measures the light emission amounts of the pre-flash and main flash of the strobe. 32 is also a light receiving element such as a photodiode for monitoring the light emitted from the xenon tube 19. By limiting the light emission current of the xenon tube 19 based on the output of the light receiving element 32, flat light emission control described later is performed. Reference numerals 20a and 20b denote light guides that are integrated with the reflection shade 20 and reflect the light of the xenon tube 19 to receive the light receiving element 32 or the fiber 3.
Lead to 0.

2 and 3 show an electric circuit of the camera system. In these figures, the members corresponding to those in FIG. 1 are designated by the same reference numerals. Camera microcomputer 1
00 operates based on the clock signal generated by the oscillator 101. The EEPROM 100b stores film counter and other shooting information. A / D converter 100c
Converts the analog signals from the focus detection circuit 105 and the photometry circuit 106 from analog to digital. Camera microcomputer 100
Sets various states by signal processing the A / D value converted by the A / D converter 100c.

The camera microcomputer 100 includes a focus detection circuit 105, a photometric circuit 106, a shutter control circuit 107,
Motor control circuit 108, film running detection circuit 10
9, switch sense circuit 110 and LCD drive circuit 1
11 are connected. In addition, the camera microcomputer 100
Transmits a signal via the lens control circuit 112 arranged in the photographing lens and the mount contact 10, and transmits a signal to the strobe microcomputer 200 in the external strobe 18 via the strobe contact group 22. .

The focus detection circuit 105 is the camera microcomputer 1
00, the CCD line sensor 29, which is a known distance measuring element, is subjected to accumulation control and readout control, and pixel information of each is output to the camera microcomputer 100.
The camera microcomputer 100 A / D-converts this information and performs focus detection by the well-known phase difference detection method. The camera microcomputer 100 also exchanges signals with the lens microcomputer 112 based on the focus detection information to adjust the focus of the lens.

The photometric circuit 106 outputs the output from the photometric sensor 7 to the camera microcomputer 100 as a luminance signal of the subject. The photometric circuit 106 outputs the luminance signal in both the steady state in which the strobe light is not pre-emitted toward the subject and the pre-emission state in which the pre-emission is performed. Then, the camera microcomputer 100 A / D-converts the luminance signal, and calculates the aperture value for adjusting the exposure of shooting, the shutter speed, and the flash main light emission amount during exposure.

The shutter control circuit 107 is responsive to a signal from the camera microcomputer 100 to drive the shutter front curtain drive magnet MG- which constitutes the focal plane shutter 8.
1 and the shutter rear curtain drive magnet MG-2 are run to perform the exposure operation.

The motor control circuit 108 controls the motor M in accordance with a signal from the camera microcomputer 100 to cause the main mirror 2 to move up and down, the shutter to be charged, and the film to be fed.

The film running detection circuit 109 detects that the film has been wound up by one frame at the time of feeding the film, and sends a signal to the camera microcomputer 100.

SW1 is a first release button (not shown).
This switch is turned on by a stroke operation to start photometry and AF. SW2 is a switch that is turned on by the second stroke operation of the release button to start the exposure operation. SWFELK is a switch for independently performing pre-light emission described later, and includes SW1, SW2, and SWFELK.
And other signals from the operating members of the camera (not shown)
The camera microcomputer 1 is detected by the switch sense circuit 110.
Sent to 00.

The liquid crystal display circuit 111 has an L in the finder.
The display of the CD 24 and the monitor LCD 42 (not shown) is controlled according to a signal from the camera microcomputer 100. SWX
Is a switch for starting the light emission of the strobe 18, and is turned on at the same time when the traveling of the shutter front curtain is completed.

Next, the interface terminals in the camera microcomputer 100 will be described. SCK is an output terminal of a synchronous clock for performing serial communication with the strobe 18, SCK
DO is a serial data output terminal for serial communication with the strobe 18, SDI is a data input terminal for serial communication with the strobe 18, and SCHG is strobe 1.
Main capacitor C1 for storing the energy for light emission of 8
Input terminal for detecting the charging completion of LCK, LCK is an output terminal of a synchronous clock for serial communication with the lens 11, LDO is a serial data output terminal for serial communication with the lens 11, and LDI is serial with the lens 11. This is a data input terminal for communication.

Next, the structure of the lens 11 will be described. The camera body 1 and the lens 11 are the lens mount contacts 1
They are electrically connected to each other via 0. The lens mount contact 10 is a power contact L0 for the focus driving motor 16 and the diaphragm driving motor 17 in the lens 11, and a power contact L1 for the lens microcomputer 112.
, A known clock contact L2 for performing serial data communication, a data transmission contact L3 from the camera 1 to the lens 11, a data transmission contact L4 from the lens 11 to the camera 1, and a motor for the motor power supply. And a ground contact L6 for the lens microcomputer 112 power supply.

The lens microcomputer 112 is connected to the camera microcomputer 100 via these lens mount contacts 10 and operates the first group lens drive motor 16 and the lens diaphragm motor 17 to control the focus adjustment and diaphragm of the lens. Reference numerals 35 and 36 are a photodetector and a pulse plate. The lens microcomputer 112 can obtain the positional information of the first group lens 12 by counting the rotation angle (pulse number) of the pulse plate 36 through the photodetector 35, and can adjust the focus of the lens.

Further, the lens microcomputer 112 reads the zoom position information (focal length information) detected by the zoom position detecting encoder 33 through Z0 to Z3, thereby dividing the tele range to the wide range into 16 bits by 4 bits. It can be detected in detail. In addition, COM is
It is a common terminal for drawing in a current having a voltage corresponding to the ground level of the zoom position detecting encoder 33.

Next, the structure of the strobe 18 will be described. The strobe microcomputer 200 is a camera microcomputer 100.
It is a circuit that controls the strobe according to the signal from
The amount of light emission is controlled, the emission intensity and emission time of flat emission are controlled, and the emission irradiation angle is controlled.

Reference numeral 201 denotes a DC / DC converter which boosts the battery voltage to three hundred and several tens of V according to an instruction from the flash microcomputer 200 to charge the main capacitor C1.

R1 / R2 are voltage dividing resistors provided for the stroboscopic microcomputer 200 to monitor the voltage of the main capacitor C1. The stroboscopic microcomputer 200 outputs the divided voltage to the A /
A / D conversion is performed by a D converter (not shown), the voltage of the main capacitor C1 is indirectly monitored, the operation of the DC / DC converter 201 is controlled, and the voltage of the main capacitor C1 is controlled to a predetermined voltage. .

Reference numeral 202 denotes a trigger circuit, which is used by the camera microcomputer 100 via the stroboscopic microcomputer 200 when strobe light is emitted.
A trigger signal is output according to the instruction received from the device, and a high voltage of several thousand volts is applied to the trigger electrode of the xenon tube 19 to induce discharge of the xenon tube 19. As a result, the charge energy stored in the main capacitor C1 is transferred to the xenon tube 1
It is emitted as light energy via 9.

Reference numeral 203 denotes a light emission control circuit using a switching element such as an IGBT. When a trigger voltage is applied during light emission, the light emission control circuit 203 is in a conductive state and a current flows through the xenon tube 19.
When the light emission is stopped, the cutoff state is set to cut off the current flow in the xenon tube 19 to stop the light emission.

Reference numerals 204 and 205 are comparators. The comparator 204 is used to stop light emission during flash light emission, which will be described later, and 205 is used to control light emission intensity during flat light emission, which will be described later. A data selector 206 selects the input from the terminal D0 to the terminal D2 in accordance with the selection signals SEL1 and SEL2 from the flash microcomputer 200, and the terminal Y
Output to

A flash emission control monitor circuit 207 logarithmically compresses and amplifies the output of the light receiving element 31. 20
Reference numeral 8 denotes an integrating circuit for integrating the output of the flash light emission control monitor circuit 207. A flat emission control monitor circuit 209 amplifies the output of the light receiving element 32. Reference numeral 210 is a writable or rewritable memory such as an EEPROM or a flash ROM for storing the flat light emission time and the like.

Reference numeral 211 is a known motor drive circuit, 212 is a strobe drive motor, 213 is a pinion gear, 214 is a rack gear, 215 is a Fresnel lens 21 of the reflection shade 20.
A strobe zoom position detection encoder 216 for detecting the position with respect to is an LED indicating that light emission is possible.

Next, each terminal of the flash microcomputer 200 will be described. CK is an input terminal for a synchronous clock for serial communication with the camera, DI is an input terminal for serial communication data, D0 is a data output terminal for serial communication, and CHG is an output terminal for transmitting the flash-enabled state to the camera as a current. , X are input terminals for light emission signals from the camera.

ECK is an output terminal for outputting a communication clock for serial communication with the memory 210 connected to the outside of the flash microcomputer 200, EDI is an input terminal for serial data from the memory 210, and EDO is a memory 210. The serial data output terminal, SELE, is an enable terminal that permits communication with the memory 210.
When the output signal from the enable terminal SELE is Lo, it is in the enable state, and when it is Hi, it is in the disable state.

Further, in the present embodiment, the memory 210 is provided outside the strobe microcomputer, but this memory 210 is
It may be built in the flash microcomputer 200.

POW is an input terminal for inputting the state of the power switch 218, OFF is an output terminal for turning off the strobe when connected to the power switch 218, and ON is a strobe when connected to the power switch 218. Is an output terminal for turning on. The input terminal POW is connected to the ON terminal in the power ON state,
At that time, the ON terminal becomes a high impedance state, and O
The FF terminal is in the Lo state. On the other hand, the opposite is true in the power-off state.

CHG_LED is a display output terminal that indicates that light emission is possible, and AEOK is a display output terminal that indicates whether or not dimming is possible.

STOP is an input terminal for a light emission stop signal. The light emission is stopped when the signal input to the input terminal STOP is Lo. SEL0 and SEL1 are output terminals for instructing the input selection of the data selector 206, and when the combination of signals from the output terminals SEL0 and SEL1 is (SEL1, SEL0) = (Lo, Lo), the D0 terminal is the Y terminal. To (Lo, H
In the case of i), the D1 terminal is connected to the Y terminal, and (Hi, L
In the case of o), the D2 terminal is connected to the Y terminal.

DA0 is an output terminal of the D / A converter built in the stroboscopic microcomputer 200, and the comparator 20
The comparator levels 4 and 205 are output as analog voltages. TRIG is a trigger signal output terminal for instructing the trigger circuit 202 to emit light. CNT is an output terminal for controlling the start / stop of charging of the main capacitor C1 by the DC / DC converter 201. When the output signal from the output terminal CNT is Hi, charging is started and when it is Lo, charging is stopped.

INT is a terminal for controlling the start / prohibition of integration of the integration circuit 208. When the output signal of the terminal INT is Hi, integration is prohibited, and when it is Lo, integration is allowed.

AD0 and AD1 are A / D input terminals,
The input voltage is converted into digital data so that it can be processed inside the microcomputer 200. AD0 monitors the voltage of the main capacitor C1, and A
D1 monitors the integrated output voltage of the integrating circuit 208.

Z0 and Z1 are strobe zoom drive motors 2
12 are control output terminals for controlling the motor control circuit 211 for driving the motor 12, ZM0, ZM1, and ZM2 are input terminals for inputting signals from the strobe zoom position detection encoder 215, and COM0 is a ground of the strobe zoom position detection encoder 215. It is a common terminal that draws in a current having a voltage corresponding to the level.

Next, the light emitting operation will be described.

<Pre-flash> When the strobe becomes ready to emit light in the basic strobe operation described above, the camera microcomputer 100 detects that the strobe is ready to emit light. Then, a signal indicating the emission intensity of pre-emission and the emission time is communicated to instruct pre-emission.

The flash microcomputer 200 sets a predetermined voltage on DA0 according to a predetermined light emission intensity signal instructed by the camera body. Next, select SEL1 and SEL0 (L
o, Hi) and select the input terminal D1. At this time, since the xenon tube 19 has not yet emitted light, the photocurrent of the light receiving element 32 hardly flows, and the signal input to the inverting input terminal of the comparator 205 is not output from the monitor circuit 209 either. Hi
Then, the light emission control circuit 203 becomes conductive. When a trigger signal is output from the TRIG terminal, the trigger circuit 202 generates a high voltage to discharge the xenon tube 19, and strobe light emission (pre-light emission) is started.

On the other hand, the stroboscopic microcomputer 200 instructs the integrator circuit 208 to start integration after a lapse of a predetermined time from the generation of the trigger, whereby the integrator circuit 208 causes the monitor circuit 20 to start.
7, the integration of the logarithmically compressed photoelectric output of the light receiving element 31 for light amount integration is started. At the same time, the flash microcomputer 200 activates a timer that counts a predetermined time. The reason why the integration start is delayed from the trigger generation is to prevent the integration circuit 208 from integrating noise other than the optical signal due to the noise generated by the trigger generation. Further, in the actual light emission, This is because there is a delay of 10s of microseconds after the trigger is generated.

When the pre-emission is started, the photocurrent of the light emission element 32 for controlling the emission intensity of the flat emission increases, the output voltage of the monitor circuit 209 rises, and this output voltage is set to the non-inverting input of the comparator 205. When the voltage becomes higher than the predetermined comparator voltage, the output of the comparator 205 is inverted to Lo, and the light emission control circuit 203 cuts off the light emission current of the xenon tube 19. This allows the xenon tube 1
Although the discharge loop of 9 is cut off, the light emitting current gradually decreases after the overshoot due to the delay of the circuit is stopped because the reflux loop is formed by the diode D1 and the coil L1.

Since the light emission intensity decreases as the light emitting current decreases, the photocurrent of the light receiving element 32 decreases, and the monitor circuit 2
When the output of 09 decreases and the output falls below a predetermined comparator level, the output of the comparator 205 is inverted to Hi again, the light emission control circuit 203 is turned on, and the discharge loop of the xenon tube 19 is formed to emit light. The current increases and the emission intensity also increases. In this way, the comparator 205 repeatedly increases and decreases the light emission intensity in a short cycle centering on the predetermined comparator voltage set to DA0, and as a result,
The flat light emission is controlled to continue the light emission at a desired substantially constant light emission intensity.

When the above-described light emission time timer counts up and the predetermined pre-light emission time elapses, the flash microcomputer 200 sets SEL1 and SEL0 to (Lo, Lo). As a result, the input of the data selector 206 is D0.
That is, the Lo level input is selected and the output is forced to L
The light emission control circuit 203 becomes the o level and the xenon tube 19
The discharge loop of is cut off and the light emission is terminated.

At the end of light emission, the flash microcomputer 200
Represents the output of the integration circuit 208 which has integrated the pre-emission, to A / D
It is read from the input terminal AD1, A / D converted, and the integrated value, that is, the light emission amount at the time of pre-light emission is read as a digital value.

<Main Light Emission Control> Next, the main light emission control will be described. There are two modes for the timing from the pre-flash to the main flash. In the first mode, pre-flashing is performed when the shutter release switch SW2 is turned on, and the camera measures the subject reflected light due to pre-flashing from the output of the photometric element 7 to obtain the proper exposure amount of the flash, and pre-flashing. Simultaneously with the end of, the aperture 15 is driven to set an appropriate aperture, and the mirrors 2 and 25 are flipped up to move away from the optical path. When the drive of the mirrors 2 and 25 is finished, the shutter 8 is opened and the main strobe light is emitted. I do. Hereinafter, this first mode will be referred to as a collective light emission mode.

In the second mode, the pre-emission switch SW
When LK is turned on, the above-described pre-flash is performed, and the camera measures the reflected light of the subject due to the pre-flash from the output of the photometric element 7 to obtain the proper exposure amount of the flash, and then the SW
When 2 is turned on, the diaphragm 15 is driven to set an appropriate diaphragm, and the mirrors 2 and 25 are flipped up to move out of the optical path. When the driving of the mirrors 2 and 25 is completed, the shutter 8 is opened and the strobe light is released. The main flash is emitted. This second mode is hereinafter referred to as FE lock mode.

In this FE lock mode, the subject is placed in the center of the photometric area for pre-flashing, and the camera is pointed at the area to be photographed next, and the shutter is released. Thus, even when the subject is not in the center of the shooting area during flash shooting, proper exposure by the flash can be obtained.

Next, the main light emitting operation will be described step by step. First, in the main light emission sequence after the shutter release switch SW2 is turned on, the camera microcomputer 100 sets the subject reflected light brightness from the photometric sensor 7 during pre-flashing and the external light brightness during natural light, the exposure mode, the film sensitivity, and the Based on the reflected light from the subject during the pre-flash,
Determine shutter speed and aperture.

Further, the camera microcomputer 100 determines the proper light emission intensity of the main light emission by the flat light emission based on the light emission upper limit data received from the flash microcomputer 200 when the shutter speed is faster than the above-mentioned flash synchronization speed. The flash microcomputer 200 is instructed of the light emission intensity and the light emission time by serial communication through the communication lines S0 to S2. For the light emission time, the shutter opening time corresponding to the shutter speed is added to the shutter speed, and a slight margin is taken into consideration in consideration of mechanical variations until the shutter curtain actually appears on the screen. It is calculated by adding time. If the shutter speed is less than or equal to the flash synchronization speed, the proper light emission amount of the main light emission by flash light emission is determined and the light emission amount is instructed to the strobe microcomputer 200.

The emission intensity and the emission amount in the main emission are defined as relative information with respect to the emission intensity and the emission amount in the pre-emission.

<Main Flat Light Emission Control> Next, main light emission control by flat light emission will be described. The stroboscopic microcomputer 200 obtains the proper light emission intensity of the main flat light emission based on the received main light emission intensity, and sets a predetermined voltage as the proper light emission intensity to the DA0 output. A method of setting the proper light emission intensity will be described later.

Next, to SEL1 and SEL0 (Lo, Hi)
Is output and input D1 is selected. At this time, xenon tube 1
Since 9 has not emitted light yet, almost no photocurrent of the light receiving element 32 flows. Therefore, the output of the monitor circuit 209 does not occur and the output of the comparator 205 becomes Hi, so that the light emission control circuit 203 becomes conductive.

Next, when a trigger signal is output from the TRIG terminal, light emission from the xenon tube 19 is started. In addition, the stroboscopic microcomputer 200 activates a timer that counts the time instructed by the camera when the light emission starts. Regarding the emission intensity control of flat emission,
Since it is the same as the pre-flash control, the description thereof will be omitted. After the above-described flash time timer counts up and a predetermined flash time has elapsed, the flash microcomputer 200 sets the SEL
1. Set the SEL0 terminal to (Lo, Lo). As a result, the input of the data selector 206 is D0, that is, Lo.
The level input is selected, the output is forcibly set to the Lo level, and the light emission control circuit 203 cuts off the discharge loop of the xenon tube 19, so that the light emission ends.

<Main Flash Emission Control> Next, the main flash control by flash emission will be described. The stroboscopic microcomputer 200 determines an appropriate light emission amount of the main flash light emission based on the received main light emission amount, and sets a predetermined voltage that is the appropriate light emission amount to the DA0 output. The predetermined voltage is obtained by adding or subtracting a voltage corresponding to the relative light emission amount to the integrated output read from AD1 at the end of the pre-light emission.

Next, to SEL1 and SEL0 (Hi, Lo)
And input D2 is selected. At this time, the integrating circuit 20
Since 8 is in the operation prohibited state, the output of the integrating circuit 208 is not generated. Therefore, the output of the comparator 204 becomes Hi, and the light emission control circuit 203 becomes conductive.

Next, when a trigger signal is output from the TRIG terminal, light emission from the xenon tube 19 is started. In addition, the stroboscopic microcomputer 200 receives the trigger noise due to the application of the trigger, and the actual light emission is started for several ten μs.
After ec, the integration start terminal INT is set to Lo level.
As a result, the integration circuit 208 integrates the output from the sensor 31 via the monitor circuit 207. DA0 integrated output
When the predetermined voltage set by is reached, the comparator 20
4 is inverted, the light emission control circuit 203 is cut off from the conduction via the data selector 206, and the light emission is stopped.

On the other hand, the stroboscopic microcomputer 200 uses the STO
When the P terminal is monitored and the STOP terminal is reversed and the light emission is stopped, the SEL1 and SEL0 terminals are set to (Lo, Lo) to set the forced light emission prohibited state, and the integration start terminal INT is inverted and the integration ends. Then, the light emission process ends.

Next, the operation flow of the camera system in the collective light emission mode will be described with reference to FIG. In Figure 4,
The flowchart for setting the light emission operation performed by the camera microcomputer 100 is shown. First, the steps (hereinafter,
In (101), it is determined whether or not the camera operation is started and the photometric distance measurement start switch SW1 is turned on. If it is on, the process proceeds to # 102, and if it is off, # 10.
Loop 1

In # 102, the focus detection operation is performed by the well-known phase difference detection method by the focus detection circuit 105, and the lens microcomputer 112 is instructed to perform focus drive to perform focus adjustment. Subsequently, in # 103, the photometric circuit 106 measures the subject brightness value Bv. Then, in step # 104, the appropriate exposure amount EvS (= Tv +) is calculated from the subject brightness and the film sensitivity.
Av) and the shutter speed and aperture according to the set exposure mode.

Next, in # 105, it is determined whether or not the release start switch SW2 is on. If it is on, the process proceeds to # 106, and if it is off, the process returns to # 101 and the above process is repeated. In step # 106, the flash microcomputer 200 is instructed to emit a predetermined amount of light, and the flash is caused to perform the pre-flash described above. Then, in # 107, the subject reflected light at the time of pre-flash is measured by the photometry circuit 106, and the exposure amount EvF of the pre-flash is measured.
Ask for.

Further, in # 108, the proper light emission amount of the main light emission with respect to the pre-light emission is obtained by subtracting the exposure amount in the pre-light emission measured in # 107 from the appropriate light exposure amount obtained in # 104. That is, the main light emission brightness (main proper light emission amount) required to obtain the proper exposure is obtained by subtracting the reflected light brightness due to the pre-flash of the strobe from the subject brightness under natural light.

Next, in # 109, whether or not dimming is possible is determined based on the main proper light emission amount obtained in # 108 and a later-described upper light emission amount upper limit value received from the strobe, and the strobe is instructed as to whether or not dimming is possible. I do. That is, the proper light emission amount of the main light emission is compared with the light emission amount upper limit value, and if the main light emission amount is larger than the light emission amount upper limit value by a predetermined value or more, it is determined that dimming is not possible, and the main proper light emission amount is If it is smaller than a value obtained by adding the above-mentioned predetermined value to the upper limit value, it is determined that dimming is possible. In addition,
This predetermined value is 0.3 EV in consideration of exposure accuracy.
~ 0.5 EV is preferable.

Next, in step # 110, the main mirror 2 and the sub mirror 25 are moved up and moved away from the photographing optical path prior to the exposure operation. Further, in # 111, the aperture value based on the exposure amount calculated in # 103 is instructed to the lens microcomputer 112 to set an appropriate aperture, and upon completion of the aperture setting, the shutter is driven via the shutter control circuit 107.

Then, in # 112, the main light emission control of the strobe is performed in accordance with the light emission amount obtained in # 108 in synchronization with the driving of the shutter. # 113 after main flash
Then, the flash microcomputer 200 is instructed to turn on the dimming confirmation LED 217 for a predetermined time according to the determination result in # 109. That is, the dimmability information determined before the main light emission is displayed even after the main light emission. Incidentally, as shown in FIG. 6, it may be displayed for a predetermined time in the viewfinder of the camera after the photographing is completed.

When the exposure operation is completed in this way, # 114
Then, the main mirror 2 and the sub-mirror 25, which have left the shooting optical path, are moved down (obliquely installed in the shooting optical path),
Motor control circuit 108 and film running detection circuit 10
The film is wound up by one frame by 9 and the operation is completed.

As described above, in the collective light emission mode,
The interval between pre-flash and main flash is short, and lens zooming and flash firing angle change (strobe zooming)
Since there is no room for this, the dimming possibility determination and the display are performed without considering the variation of the strobe irradiation angle.

Next, the operation flow of the camera system in the FE lock mode will be described with reference to FIG. FIG. 5 shows a flowchart for setting the light emission operation performed by the camera microcomputer 100. First, in # 201,
The camera starts operating, and S, which is the FE lock switch
It is determined whether WFEL is turned on, and if it is turned on, #
The process proceeds to 202, and if off, the process proceeds directly to # 207.

At # 202, the photometric circuit 106 measures the subject brightness value Bv. Then, in step # 203, the appropriate exposure amount EvS (= Tv +) is calculated from the subject brightness and the film sensitivity.
Av) and the shutter speed and aperture according to the set exposure mode.

Next, in # 204, the flash microcomputer 20
A predetermined light emission amount is instructed to 0, and the strobe is caused to perform pre-light emission. Then, in # 205, the subject reflected light at the time of the pre-flash is measured by the photometry circuit 106, and the exposure amount E of the pre-flash is emitted.
Find vF.

Further, in # 206, the proper light emission amount of the main light emission with respect to the pre-light emission is obtained by subtracting the exposure amount during the pre-light emission measured in # 205 from the appropriate light exposure amount obtained in # 203. That is, the main light emission brightness (main proper light emission amount) required to obtain the proper exposure is obtained by subtracting the reflected light brightness due to the pre-flash of the strobe from the subject brightness under natural light.

In # 207, it is determined whether or not pre-light emission has been performed, and if it has been performed, the process proceeds to # 208, and if it has not been performed, the process proceeds to # 210. In # 208, whether or not dimming is possible is determined based on the main proper light emission amount obtained in # 206 and the below-described light emission amount upper limit value received from the strobe. That is, the proper light emission amount of the main light emission is compared with the light emission amount upper limit value, and if the main light emission amount is larger than the light emission amount upper limit value by a predetermined value or more, it is determined that the light adjustment is impossible, and the main proper light emission amount is
If it is smaller than the value obtained by adding the above predetermined value to the upper limit value of the light emission amount, it is determined that the light control is possible. The predetermined value is preferably 0.3 EV to 0.5 EV in consideration of exposure accuracy.

Next, at # 209, as shown in FIG. 6, if the dimming is possible, the flash mark is turned on, and if the dimming is not possible, the flash mark is blinked to warn the photographer. In the present embodiment, the flash mark is turned on.
Although the result of the dimming possibility determination is displayed by blinking, for example, by displaying the difference between the main proper light emission amount and the light emission amount upper limit value on the exposure level display section as shown in FIG. May be displayed.

At # 210, it is determined whether or not the switch SW1 which is a photometric distance measuring start switch is turned on.
The process proceeds to step 211, and if it is off, the process returns to step # 201 to repeat the process. It should be noted that the display in # 209 is updated with the change in the stroboscopic irradiation angle each time when # 208 and # 209 are repeatedly passed. As a result, whether or not dimming is possible and the display is performed in real time after pre-emission and before main emission. In # 211, the focus detection circuit 10
The focus detection operation is performed by the well-known phase difference detection method of 5, and the lens microcomputer 112 is instructed to perform focus drive to perform focus adjustment. Next, in # 212, it is determined whether or not the release start switch SW2 is turned on. If it is on, the process proceeds to # 213, and if it is off, the process returns to # 201.

At # 213, the photometric circuit 106 re-meters the subject brightness value Bv (= Bvo + Avo). This is to cope with the composition change after the pre-emission. Then, in # 214, the appropriate exposure amount EvS (= Tv + Av) is determined from the subject brightness and the film sensitivity, and the shutter speed and aperture are determined according to the set exposure mode. Subsequently, in # 215, the main mirror 2 and the sub mirror 25 are moved up and moved out of the photographing optical path prior to the exposure operation.

Then, in # 216, the aperture value based on the exposure amount calculated in # 214 is instructed to the lens microcomputer 112 to set an appropriate aperture, and when the aperture is set, the shutter control circuit 107 is instructed to release the shutter. Drive. Further, in # 217, the strobe microcomputer 200 is caused to perform main strobe control of the strobe in accordance with the amount of light emission obtained in # 206 in synchronization with the driving of the shutter.

After the main light emission, in # 218, the flash microcomputer 200 is instructed to turn on the dimming confirmation LED 217 for a predetermined time according to the latest determination result in # 208. When the exposure operation is completed in this way, # 219
Then, the main mirror 2 and the sub-mirror 25 that have retreated from the shooting optical path are moved down (obliquely installed in the shooting optical path), and the motor control circuit 108 and the film running detection circuit 109 wind up the film by one frame, and the operation is completed. .

As described above, in the FE lock mode, the interval between the pre-light emission and the main light emission can be arbitrarily selected by the photographer's judgment, and after the pre-light emission, the lens zooming and the change of the strobe irradiation angle (the stroboscopic zooming) linked thereto are performed. ) Is possible, the determination and display of dimming availability are updated in real time after pre-flashing.

Next, the correspondence between the strobe irradiation angle (hereinafter referred to as strobe zoom position) and the upper limit of the light emission amount will be described with reference to FIG.

FIG. 11A is a diagram showing the relationship between the strobe zoom position and the guide number, and FIG.
The relationship between the flash zoom position and the guide number is shown by the EV difference with the wide end as a reference. Further, FIG. 7C shows an example of data in the graphs of FIGS.

As can be seen from these figures, when pre-lighting at the tele end and then zooming to the wide end, the guide number is halved and the light emission amount is reduced by two steps. On the contrary, when pre-flashing at the wide end and zooming to the tele end, the guide number is doubled and the light emission amount is increased by two steps. Therefore,
If zooming is performed after the pre-flash, the total flash output will be effective unless the flash output upper limit and dimming judgment are updated according to the maximum flash output (flash output upper limit) that fluctuates due to zooming. Not only can it not be used, but it also affects the exposure accuracy.

A method of determining whether or not dimming is possible and a method of calculating the upper limit value of the light emission amount according to the light amount variation after zooming will be described below with reference to FIG. In this figure, the stroboscopic microcomputer 200 is shown.
7 is a flowchart showing the operation of calculating the light emission amount upper limit value data performed by the above. First, in # 301, ZM0
~ Read out the flash zoom position from the ZM2 terminal and
In 02, the light amount variation ΔEV from the pre-flash is obtained from the stored value of the strobe zoom position at the pre-flash by the following formula.

ΔEV = EV _pre −EV _main EV _pre : Light intensity correction value corresponding to strobe zoom position during _pre -flash EV _main : Light intensity correction value corresponding to current strobe zoom position EV _pre and EV _main are The data of the light amount correction value (EV difference) shown in FIG.
Although it is stored in a ROM (not shown), the data may be stored in the memory 210.

Next, in step # 303, the upper limit value of the light emission amount = FPH
_LIMIT is calculated by the following equation. FPH_LIMIT = FPH_LIMIT _pre + ΔEV FPH_LIMIT _pre : Emission amount upper limit value during _pre -emission ΔEV: Light amount fluctuation amount obtained in # 302 Note that the emission amount upper limit value during pre-emission here is the main light emission amount during pre-emission It is data showing the amount of emitted light. For example, define the amount of light emission with 8-bit data,
When 1EV is defined as 10H (hexadecimal), if the amount of light emitted during pre-emission is a predetermined amount nnH that is m steps lower than the maximum amount of light emitted during main emission, then the upper limit of the amount of emission of main emission during pre-emission is: It becomes nnH + m0H. After that, when the amount of light emission that is 1 EV higher than that during the pre-light emission is obtained by zooming, the upper limit value of the main amount of light emission is nnH + m0H +
It becomes 10H.

Then, in # 304, the upper limit of the light emission amount obtained in # 303 is transmitted to the camera. Camera microcomputer 100
As described above, the received light emission amount upper limit value is compared with the light emission amount required for the main light emission to determine whether or not dimming can be performed during zooming.

As described above, in the present embodiment, the upper limit of the light emission amount of the main light emission is calculated in real time based on the flash zoom position, and the adjustment determined by the magnitude of the upper limit of the light emission amount and the proper main light emission amount is performed. The light availability is displayed in real time before shooting. Therefore, even if it is determined that dimming is not possible during pre-flashing, if dimming is possible due to zooming to the tele side after that, or if dimming is possible during pre-flashing, it is possible to switch to the wide side after that. When the dimming cannot be performed due to zooming, the photographer can be surely informed of these before photographing. In the former case, the main light emission can be performed up to the upper limit of the light emission amount (increased by zooming to the telephoto side) according to the changed strobe zoom position, so that the main light emission amount becomes insufficient. It is possible to prevent light emission and achieve highly efficient and reliable flash photography.

Moreover, since the judgment result of whether or not the light control is possible is displayed even after the main light emission, it is possible to perform a post-check of the highly reliable light control result without an error due to a difference in film reflectance such as TTL light control. .

(Second Embodiment) In the second embodiment, in order to inform the photographer in detail of the information on whether or not dimming is possible, there is provided means for displaying the deviation between the upper limit value of the light emission amount and the appropriate light emission amount. And Note that the hardware configuration is the same as that of the first embodiment, so description will be omitted.

FIG. 9 shows the in-viewfinder display device 24 of the camera system of this embodiment. The lower part of the camera finder is the same as that of the first embodiment, except that the light-emission level is displayed on the right part of the finder. It should be noted that the same display may be performed on the monitor display device 42 provided above the camera.

FIG. 9A shows a focal length of 35 m as an example.
Shows the display state of dimming availability immediately after pre-flash at m position,
The current exposure level is shown on the right. Since the amount of light is insufficient in this state, the exposure level display blinks to warn.

FIG. 9B shows a state in which the light amount was under the light immediately after the pre-emission, but after that, the light amount became appropriate due to zooming to the tele end (105 mm).

Next, with reference to FIG. 10, a calculation flow for performing the above display in flash photography will be described. Since the above display is particularly suitable for the FE lock mode, the display calculation flow in the FE lock mode will be described here. It should be noted that this calculation is performed by referring to FIG.
No. 208 is the same as that in FIG. 5, and the description thereof will be omitted.

FIG. 10 illustrates the flow of a program between the camera microcomputer 100 and the flash microcomputer 200. The processing from # 401 to # 404 is performed by the flash microcomputer 200, and thereafter, the processing is performed by the camera microcomputer 10.
It is a process by 0.

First, in # 401, the flash microcomputer 20 is started.
For 0, the strobe zoom position is read from the terminals ZM0 to ZM2, and in # 402, the light amount variation ΔEV from the preflash is calculated from the strobe zoom position (stored value) at the preflash using the following formula.

ΔEV = EV _pre −EV _main EV _pre : Light intensity correction value corresponding to strobe zoom position during _pre -flash EV _main : Light intensity correction value corresponding to current strobe zoom position EV _pre and EV _main are The data of the light amount correction value (EV difference) shown in FIG.
Although it is stored in a ROM (not shown), the data may be stored in the memory 210.

Next, in # 403, the upper limit value of the light emission amount = FPH
_LIMIT is calculated using the following equation.

FPH_LIMIT = FPH_LIMIT _pre + ΔEV FPH_LIMIT _pre : Emission amount upper limit value during _pre -emission ΔEV: Light amount variation amount obtained in # 402 The emission amount upper limit value during pre-emission here is the same as in the first embodiment. As described in # 303, it is data indicating the amount of main light emission that can be emitted during pre-light emission.

Then, in # 404, the upper limit value of the light emission amount obtained in # 403 is transmitted to the camera microcomputer 100.

At # 405, when the camera microcomputer 100 receives the light emission amount upper limit value from the flash microcomputer 200, #
In 406, the difference (whether dimming is possible) with the upper limit value of the light emission amount is calculated based on the main proper light emission amount obtained in # 206 of FIG.

Next, in # 407, based on the value obtained in # 406, the emission amount upper limit level for the current strobe zoom position is displayed in the viewfinder through the liquid crystal display circuit 111 as shown in FIG. It is displayed on the device 24 and the monitor display device 42 above the camera.

As a result, the photographer can confirm whether or not the light can be adjusted before photographing, and can judge the difference from the proper exposure amount. Therefore, it is possible to confirm not only whether or not dimming is possible due to zooming after pre-emission, but also how much light quantity is insufficient before dimming before dimming. It should be noted that the display may be performed even after shooting.

As described above, in the present embodiment, whether or not dimming is possible is displayed in real time before photographing, and the upper limit value of the light emission amount is calculated and displayed according to zooming. You can check the difference in advance. Therefore, if it is confirmed that proper exposure cannot be obtained after shooting after zooming and the main light emission is not performed, the main light emission in which the light emission amount is insufficient can be prevented, and the light emission energy can be effectively used. .

(Third Embodiment) FIG. 11 shows a third embodiment of the present invention.
It is an electric circuit block diagram of the camera system of an embodiment. In this figure, the members corresponding to those in FIG. In this embodiment, the strobe 18 also has the exposure amount display function described in the second embodiment.

In the figure, 220 is a liquid crystal display circuit, and 221 is a monitor liquid crystal display.

Further, FIG. 12 shows a liquid crystal display 221.
Is a display example of. Reference numeral 230 is a display showing a photographing mode, and 231 is a display showing a lens aperture value. Also,
Reference numeral 232 is a display showing the focal length of the lens, 233 is an exposure level display showing whether or not dimming is possible, and 234 is a photographable distance display.

Next, with reference to FIG. 13, a calculation flow for performing the above display in flash photography will be described. Since the above display is particularly suitable for the FE lock mode, the display calculation flow in the FE lock mode will be described here. It should be noted that this calculation is performed by referring to FIG.
No. 208 is the same as that in FIG. 5, and the description thereof will be omitted.

First, in # 501, the strobe zoom position is read out from the terminals ZM0 to ZM2, and in # 502, the light amount variation ΔEV from the pre-flash is calculated from the stored value of the strobe zoom position during the pre-flash using the following formula. Ask for.

ΔEV = EV _pre −EV _main EV _pre : Light intensity correction value corresponding to strobe zoom position during _pre -flash EV _main : Light intensity correction value corresponding to current strobe zoom position EV _pre and EV _main are The data of the light amount correction value (EV difference) shown in FIG.
Although it is stored in a ROM (not shown), the data may be stored in the memory 210.

Next, in # 503, the upper limit value of the light emission amount = FPH
_LIMIT is calculated using the following equation.

FPH_LIMIT = FPH_LIMIT _pre + ΔEV FPH_LIMIT _pre : light emission amount upper limit value during _pre -light emission ΔEV: amount of light amount variation obtained in # 502 The light emission amount upper limit value during pre-light emission here is the same as in the first embodiment. As described in # 303, it is data indicating the amount of main light emission that can be emitted during pre-light emission.

Then, in # 504, the upper limit value of the light emission amount, the aperture value, and the film sensitivity obtained in # 503 are received from the camera microcomputer 100.

At # 505, from the difference between the main proper light emission amount received from the camera microcomputer 100 and the light emission amount upper limit value at the current strobe zoom position obtained at # 503,
The current exposure level is calculated and displayed on the exposure level display section 233 of the liquid crystal display 221. Further, the current dimmable range is calculated based on the guide number at the current strobe zoom position obtained in # 503, the aperture value and the film sensitivity received from the camera microcomputer 100, and the result is displayed on the distance display section 234 of the liquid crystal display 221. .

As described above, after the pre-emission, the difference between the upper limit of the light emission amount and the appropriate light amount for the current strobe zoom position and the dimming control are displayed on the display unit 221 provided on the camera 1 and the display unit 221 provided on the strobe 18. By displaying the possible range, the photographer can determine whether or not dimming is possible and whether or not the subject is within the dimmable range before photographing. Also, by updating the display occasionally depending on the change of the strobe zoom position after pre-flash, it is possible to determine whether or not dimming is possible after the strobe zoom position is changed, the dimmable range, and how much is not dimmed. Before shooting, you can check if the amount of light is insufficient. The display may be performed for a predetermined time even after the shooting.

As described above, according to this embodiment, the strobe zoom position is detected and the dimmable range is calculated and displayed at each time point after the pre-flash and before the main flash, so that the subject is adjusted at the pre-flash time. If the subject is out of the light controllable range but enters the light controllable range due to subsequent zooming to the tele side, or the subject was in the light controllable range at the time of pre-flashing, but then zooming to the wide side With this, when the light is out of the dimmable range, it is possible to clearly inform the photographer of these, and it is possible to perform highly reliable flash photography in which the dimmable range can be determined in real time before shooting.

The present invention may be used by combining the above-described embodiments and modified examples, or the technical elements thereof as needed.

Moreover, the present invention is applicable to various types of cameras such as a single-lens reflex camera, a lens shutter camera, a video camera, optical devices other than cameras, and other devices, and those cameras, optical devices and other devices. The present invention can also be applied to devices applied to the above or elements constituting these devices.

(Relationship Between Embodiment and Claims) In the above examples, the stroboscopic zoom position detecting encoder 215 requests the irradiation area detecting means in the claims to claim # 303 and # 403 in the stroboscopic microcomputer 200. # 503 corresponds to the upper limit value calculating means in the above range, and # 503 corresponds to the dimming range calculating means in the claims.

In addition, # 1 in the camera microcomputer 100
09, # 208, and # 406 are the determination means referred to in the claims, and are the stroboscopic microcomputer 200 and the light emission control circuit 203.
Corresponds to the light emission control means in the claims, and the camera-side in-viewfinder display device 24, the monitor display device 42, the strobe-side dimming confirmation display LED 217, and the monitor LCD 221 correspond to the display means in the claims. To do.

The above is the correspondence relationship between each configuration of the present invention and each configuration of the embodiment, but the present invention is not limited to the configuration of these embodiments, and the mechanism or the embodiment shown in the claims is not limited. Any structure may be used as long as the function of the structure can be achieved.

[0141]

As described above, in the first invention of the present application, the dimming possibility is determined by detecting the strobe irradiation area after the pre-emission and before the main emission. For this reason, when the present invention is used, it is possible to adjust the light during pre-flashing, but then it becomes impossible to adjust the light by zooming to the wide side, or when dimming is impossible during pre-flashing, but to the tele side after that. When the dimming becomes possible due to the zooming, it is possible to clearly inform the photographer by displaying these before photographing. Further, in the present invention, if the main light emission is controlled based on the light emission upper limit value increased by the zooming to the tele side after the pre-light emission, it is possible to prevent the main light emission in which the light emission amount is insufficient, and the light emission energy is reduced. It is possible to make effective use of and efficient shooting.

Further, in the second invention of the present application, the determination result of the dimming possibility is displayed even after the main light emission. Therefore, according to the present invention, it is possible to check whether or not the light control is properly performed after photographing without being affected by the reflectance of the film unlike the TTL light control.

Further, in the third invention of the present application, the strobe irradiation area is detected before the main light emission, and the dimmable range is calculated and displayed. Therefore, according to the present invention, when the subject is out of the dimmable range at the time of pre-flashing but enters the dimmable range by zooming to the tele side after that, or the subject is dimmed at the time of pre-flashing. If the distance is within the possible range but then falls out of the dimmable range due to zooming to the wide side, it is possible to clearly inform the photographer of these before photographing.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a camera system that is a first embodiment of the present invention.

FIG. 2 is a block diagram of an electric circuit of the first embodiment.

FIG. 3 is a block diagram of an electric circuit of the first embodiment.

FIG. 4 is a flowchart showing an operation of the camera of the first embodiment.

FIG. 5 is a flowchart showing an operation of the camera of the first embodiment.

FIG. 6 is a diagram showing a display example of a camera in the first embodiment.

FIG. 7 is a graph diagram illustrating an upper limit value of a flash emission amount in the first embodiment.

FIG. 8 is a flowchart showing an operation of the flash in the first embodiment.

FIG. 9 is a diagram showing a display example of a camera in the second embodiment of the present invention.

FIG. 10 is a flowchart showing an operation of the camera system of the second embodiment.

FIG. 11 is an electric circuit block diagram of a third embodiment of the present invention.

FIG. 12 is a diagram showing a display example of a strobe in the third embodiment.

FIG. 13 is a flowchart showing an operation of a flash in the third embodiment.

[Explanation of symbols]

 19 Xenon tube 31, 32 Monitor sensor (PD1) 100 Camera microcomputer 200 Strobe microcomputer 203 Emission control circuit 204, 205 Comparator 207 Integration circuit 215 Strobe zoom position detection encoder

Claims (12)

[Claims] 1. A camera system for performing pre-flash photometry before main flash of a flash whose irradiation area is variable and calculating a control value at the time of main flash based on the photometry result. Irradiation area detection means for detecting an area, upper limit value calculation means for calculating an emission upper limit value based on the detection result of the irradiation area detection means, and the upper limit value calculation means after the control value and the pre-emission. And a determination unit that determines whether or not dimming by the main light emission is performed based on the light emission upper limit value. 2. The camera system according to claim 1, further comprising irradiation area control means for changing an irradiation area of the strobe according to a focal length of a photographing lens of the camera. 3. The light emission control means for controlling the main light emission based on the light emission upper limit value calculated by the upper limit value calculation means after the pre-light emission, according to claim 1 or 2. Camera system. 4. The upper limit value calculating means uses the upper limit value of light emission set according to the irradiation area of the strobe and the upper limit value of light emission at the time of pre-light emission, and emits light at the time of detection by the irradiation area detecting means. The camera system according to claim 1, wherein an upper limit value is calculated. 5. The camera system according to claim 1, wherein the control value during the main light emission is represented as a relative amount of the light emission value during the pre-light emission. 6. The camera system according to claim 1, further comprising a display unit that displays a determination result of the determination unit. 7. The camera system according to claim 6, wherein the display unit displays the determination result by turning on and off a predetermined display element. 8. The camera system according to claim 6, wherein the display unit displays the determination result by displaying a difference between the control value and the light emission upper limit value at the time of detection. 9. The camera system according to claim 6, wherein the display unit displays the determination result even after the main light emission. 10. A camera system for performing pre-flash photometry before main flash of a flash whose irradiation area is variable, and calculating a control value at the time of main flash based on the photometry result. An irradiation area detecting means for detecting an area; and a dimming range calculating means for calculating a dimmable range by the main light emission based on a detection result of the irradiation area detecting means before the main light emission. Camera system. 11. The camera system according to claim 10, wherein the control value at the time of main light emission is represented as a relative amount of light emission at the time of pre-light emission. 12. A display unit for displaying a calculation result by the dimming range calculation unit.
The camera system according to 0 or 11.