JPS646443B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD This invention relates to an exposure control device for flash photography. BACKGROUND OF THE INVENTION Conventionally, flashlight emitting devices that emit light by a preset amount are well known. However, with this type of flashlight emitting device, in order to take photography that takes into account the ratio of the amount of contribution of steady light and flashlight to photography (difference in apex value), that is, the lighting contrast, the photographer must adjust the brightness of the subject and It was necessary to calculate the lighting contrast from the exposure time and the set amount of light emitted. Purpose This invention has been made in response to the above-mentioned need, and its purpose is to provide an exposure control device or setting for controlling the amount of flash light emission based on the lighting contrast set within the flash light emitting device or camera body. The present invention aims to provide an exposure control device that displays a lighting contrast corresponding to the amount of contribution of flash light to photography, and causes a flash light emitting device to emit light in accordance with the set amount of light emission. In other words, the first invention includes a photometry circuit that measures ambient light, and an output device that outputs a signal according to a set exposure time, and that determines the amount of contribution of ambient light to photography and the amount of contribution of flash light to photography. an output device that outputs a signal corresponding to lighting contrast defined as the ratio of For flash photography, comprising: an arithmetic circuit that calculates the amount of contribution; and a control circuit that controls the amount of flash light emitted based on a signal from the arithmetic circuit and a signal corresponding to the amount of light reflected from the subject of the flash. It is an exposure control device. Further, the second invention includes a photometry circuit that measures steady light, and an output device that outputs a first signal according to a set film sensitivity and a second signal according to a set aperture value, and an output device that outputs a signal corresponding to lighting contrast defined as the ratio of the amount of contribution of light to photography and the amount of contribution of flash to photography; this lighting contrast output device; the photometry circuit; and the film sensitivity and aperture. a signal corresponding to an exposure time that provides a proper exposure based on a signal from a value output device, and
An arithmetic circuit that calculates a signal corresponding to the amount of contribution of the flash to photography, and a signal from this calculation circuit that corresponds to the amount of contribution of the flash to photography and a signal corresponding to the amount of light reflected from the subject of the flash to calculate the amount of flash light emission. This is an exposure control device for flash photography characterized by comprising a control circuit that controls the shutter according to a signal corresponding to an exposure time. Furthermore, a third invention includes a photometry circuit that measures ambient light, an output device that outputs a signal according to a set exposure time, and a setting device that sets the amount of contribution of flash light to photography; an arithmetic circuit that calculates a lighting contrast defined as a ratio of the amount of contribution of steady light to the amount of contribution to photography and the amount of contribution of flash light to photography, based on signals from the amount setting device, the photometry circuit, and the output device; Lighting based on signals from the circuit
A display device that displays contrast, and control that controls the amount of flash light emission based on a signal corresponding to the amount of flash light that contributes to photography set in the flash light contribution amount setting device and a signal that corresponds to the amount of light reflected from the subject of the flash light. This is an exposure control device for flash photography characterized by comprising a circuit. Furthermore, the fourth invention includes a photometry circuit that measures ambient light, and an output device that outputs a first signal according to a set film sensitivity and a second signal according to a set aperture value, and A setting device for setting the amount of contribution of flash light to photography, a signal corresponding to an exposure time for a proper exposure based on signals from the flash contribution amount setting device, the photometry circuit, and the output device, and photography of ambient light. an arithmetic circuit that calculates a lighting contrast defined as a ratio between the amount of contribution to the flash and the amount of contribution to the flash photography;
A display device that displays lighting contrast based on the signal from this arithmetic circuit, a signal corresponding to the amount of contribution of the flash to photography set in the flash contribution amount setting device, and a signal corresponding to the amount of light reflected from the subject of the flash. An exposure control device for flash photography, comprising a control circuit that controls the amount of flash light emitted based on a signal and controls a shutter according to a signal corresponding to an exposure time calculated by the calculation means. . Embodiments Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings. First, to explain the principle of this invention, lighting contrast is the ratio of the effects of flash light and steady light on a subject, that is, the difference when expressed in apex system. This lighting contrast is Δ ₁ , and the amount of light emitted by the flash is QVf (hereinafter, in the specification, QVf is expressed as the amount of light emitted by the flash, but in reality, QVf is related to the amount of light emitted by the flash, and the amount of light emitted by the flash is It indicates the amount of contribution (in other words, the amount of light reflected from the subject or the amount of light incident on the subject, and is not like the guide number of a strobe device), the brightness of the subject by BVa, and the exposure time.
When TV is used, the relationship is Δ ₁ =QVf−(BVa−TV) (1). Here, if the lighting contrast Δ ₁ and the exposure time TVs are set and the subject brightness BVa is output from the photometry circuit, then QVf=Δ ₁ +(BVa−TVs) (1-1) can be found. Furthermore, the aperture value AVfa that provides proper exposure can be determined as follows. In other words, if the film sensitivity is SV, then there is the following relationship: 2 ^SV・(2 ^QVf + 2 ^BVa − TVs) = 2 ^AVfa ...(2) If we transform the above equation (2) using equation (1-1), we get 2 ^SV・(2 ^QVf +2 ^QVf −Δ ₁ )=2 ^AVfa …(2-1), and taking the logarithm of both sides of the above equation (2-1), AVfa=QVf+SV+log ₂ (1+2 ^- 〓 ¹ ) … (3) becomes. Therefore, when exposure time TVs and lighting contrast Δ ₁ are set,
From (1-1) above, the flash light emission amount QVf is determined, and the aperture value AVfa for proper exposure is determined by calculating log ₂ (1-2 ^- 〓 ¹ ) based on the lighting contrast Δ ₁ and using this value and Flash amount
It can be found by adding QVf and film sensitivity SV. Also, when the exposure time TVs and the aperture value AVs are set, the aperture value AVfa that gives the appropriate exposure is determined according to the above formula (3), and this AVfa and the above aperture value are
What is necessary is to display the difference with AVs. Next, when the aperture value AVs is set, the appropriate exposure time at this time is TVx, and the relationship is 2 ^SV・(2 ^QVf + 2 ^BVa - TVx) = 2 ^AVs ...(2-2) be. Furthermore, since Δ ₁ = QVf−(BVa−TVx) …(1-2), equation (2-2) becomes 2 ^SV・(2 ^QVf +2 ^QVf −Δ ₁ )=2 ^AVs …(2-3), By taking the logarithm of both sides and rearranging, we obtain QVf=AVs−SV−log ₂ (1+2 ⁻ 〓 ¹ )…(4). Furthermore, the exposure time TVx is determined from TVx=Δ ₁ +BVa−QVf (1-3). Furthermore, if the flash output QVf is set,
First, when the exposure time TVs is set, the lighting contrast is determined from Δ ₁ =QVf−(BVa−TVs) (1-4), and the above equation (3) is determined from this value Δ ₁ . To set the amount of flash light emitted, that is, the contribution amount QVf of flash light to photography, for example, emit a flash from a strobe device in advance, and then calculate the amount of light reflected from the subject or the amount of light incident on the subject due to the emitted light. It is sufficient to measure the light using a photometer and set the apex value based on the measured value. Furthermore, when both the exposure time TVs and the aperture value AVs are set, the aperture value AVfa that provides the appropriate exposure may be determined from the above equation (3), and the difference from the set aperture value AVs may be displayed. Next, when the set aperture value AV ₃ is set, there is a relationship of 2 ^SV・(2 ^QVf + 2 ^BVa-TVx ) = 2 ^AVS ...(2-2), where AVf=QVf+SV...(5 ), find the appropriate aperture value AVf when only flash light is emitted (when there is no steady light), find Δ ₃ = AV ₃ − AVf …(6), and transform the above equation (2-2). , 2 ^BVa+SV-TVx = 2 ^AVS (1-2 ^- 〓 ³ )...(2-4). Then, take the logarithm of both sides of the above equation (2-4),
By rearranging, we get TVx=BVa+SV−AVs−log ₂ (1−2 ^- 〓 ³ ) …(7), and the lighting contrast is Δ ₁ =QVf−(BVa−TVx) …(1−2) Determined from In addition, in the case of a so-called program shutter camera that automatically determines the combination of exposure time TVs and aperture value AVs based on the subject brightness BVa, the combination of exposure time TVs and aperture value AVs is determined in the same way as when only exposure time TVs is set. All you have to do is process it. Next, a specific configuration of the present invention will be explained with reference to FIGS. 1 to 18. First, FIG. 1 is a block circuit diagram showing the basic configuration of a first embodiment of the present invention, in which 1 is a photometry circuit that measures ambient light, 2 is an exposure control value setting device,
3 is an arithmetic circuit, and 4 is an integral type photometry circuit that measures only the amount of flash light, that is, only the strobe light. Further, 5 is a signal conversion circuit, 6 is an aperture control device, 7 is a shutter control device, 8 is a display device, 9
1 is a comparator, and 10 is a strobe device. It is assumed that a signal corresponding to a lighting contrast Δ ₁ set by a lighting contrast setting device (not shown) is input from the strobe device 10 to the arithmetic circuit 3. As a result, the signals from the photometry circuit 1 and the exposure control value setting device 2 are calculated according to the above formula,
Arithmetic circuit 3 outputs the flash light amount QVf and exposure time.
TV and Δ ₂ are output. Here, _Δ2 is the aperture value AVfa calculated based on the exposure time TVs and the set aperture value when exposure control is performed by so-called manual setting, in which both the exposure time TVs and the aperture value AVs are set. Corresponds to the difference with AVs. The output signal from this arithmetic circuit 3 is displayed on a display device 8.
The diaphragm and shutter are controlled in addition to the diaphragm control device 6 and the shutter control device 7. On the other hand, the amount of light emitted by the strobe device 10 is controlled as follows. That is, a light receiving element (not shown) included in the photometry circuit 4 is provided at a position to receive reflected light from a film surface (not shown). Therefore, when the amount of light emitted from the strobe device 10 is QVf, the amount of light incident on the light receiving element is:
When the aperture value is AV, QVf - AV. Therefore, from the signal conversion circuit 5, the above QVf-
An analog signal corresponding to AV is output and compared with the output signal from the photometry circuit 4 by a comparator 9. When both signals have a predetermined relationship, the output of the comparator 9 is inverted, and the strobe device 10 stops emitting light based on this inverted signal. Figure 2 shows the exposure time in the configuration of Figure 1.
This is a block diagram of the arithmetic circuit 3 in a camera in which TV is set, in which 20 is a register where lighting contrast _Δ1 is set, 21 is a register where ambient light brightness BVa is set, and 22 is exposure time TVs. The register 23 to be set is a register in which the film sensitivity SV is set. Then, in the subtraction circuit 24, both registers 2
Based on the signals from 1 and 22, BVa-TVs
The following calculations are performed. Further, the addition circuit 25 calculates QVf=Δ ₁ +(BVa−TVs) (1-1) based on the above calculation result and the signal from the register 20, and calculates the amount of light emitted by the strobe device 10.
QVf is calculated. Also, based on the signal from the register 20,
If you specify the address of ROM26, ROM26
Data corresponding to log ₂ (1+2 ^- 〓 ¹ ) stored in is read out. Based on this read data, the signal from the adder circuit 25, and the signal from the register 23, the adder circuit 27
Then, AVfa=QVf+SV+log ₂ (1+2 ^- 〓 ¹ )...(3) is calculated, and the aperture value for proper exposure is determined.
AVfa is calculated. Figure 3 shows the aperture value for the configuration shown in Figure 1.
It is a block diagram of the arithmetic circuit 3 in a camera of the type in which AVs is set, and 30 is a register for setting the aperture value AVs. Then, data corresponding to log ₂ (1+2 ^- 〓 ¹ ) is read out from the ROM 26, as in the case of FIG. Based on this read data, the signal from the register 30, and the signal from the register 23, the subtraction circuit 31 calculates QVf=AVs-SV-log ₂ (1+2 ^- 〓 ¹ )...(4) is performed, and the amount of light emitted by the strobe device 10 is
QVf is calculated. Also, both registers 20 and 21
Based on the signal from the adder circuit 32,
The calculation of BVa+ _Δ1 is performed. Based on this calculation result and the signal from the subtraction circuit 31, the subtraction device 33 calculates the following: TVx=BVa+Δ ₁ −QVf (1-3), and the exposure time to obtain the appropriate exposure.
TVx is calculated. Figure 4 shows the aperture value for the configuration shown in Figure 1.
This is a block diagram of the arithmetic circuit 3 in a camera in which both AVs and exposure time TVs are set, and as in the case of FIG. The aperture value AVfa is calculated. Then, based on the data corresponding to the above calculated aperture value AVfa and the set aperture value AVs,
The subtraction circuit 34 calculates the above Δ ₂ =AVfa−AVs
is now being calculated. Note that in FIGS. 3 and 4, parts having the same structure and function as those in FIG. 2 are designated by the same reference numerals. Next, FIG. 5 is a block circuit diagram showing the basic configuration of a second embodiment of the present invention.
In this embodiment, unlike the first embodiment, the light emission amount QVf of the strobe device 35 output from the arithmetic circuit 3
The data corresponding to is processed by the DA converter 36,
converted to an analog signal. Then, this analog signal is input to the strobe device 35, and the photometry circuit 4a and comparator 9 provided in the strobe device 35 are input to the strobe device 35.
a. The light emission is controlled by the light emission stop circuit 37 in the same manner as in the first embodiment. In FIG. 1, when the light-receiving element of the photometry circuit 4 is provided at a position where it receives the subject light that does not pass through the photographic aperture, the input terminal of the comparator 9, as in the case of FIG. Data corresponding to the light emission amount QVf of the strobe device 35 may be added. Furthermore, FIG. 6 is a block circuit diagram showing the basic configuration of a third embodiment of the present invention.
In this embodiment, unlike the first and second embodiments, the strobe device 40 includes a setting circuit 41 that outputs a signal corresponding to the light emission amount QVf. Then, the light emission amount QVf from this light emission amount setting circuit 41,
The lighting contrast Δ 1 is calculated by the arithmetic circuit 42 based on the photometric value of the steady light from the photometric circuit 1 and the data corresponding to the exposure control value from the exposure control value setting device ₂ . Furthermore, the signal from the light emission amount setting circuit 41 is applied to one input terminal of the comparator 9a, and the signal from the photometry circuit 4a is applied to the other input terminal, so that the light emission amount QVf becomes the set value. It's becoming like that. Figure 7 shows the exposure time in the configuration of Figure 6.
This is a block diagram of an arithmetic circuit 42 in a camera in which TVs are set. Components having the same configuration as the second, third, and fourth circuits described above are given the same reference numerals, and 43 is a block diagram from a strobe device 40. This register is set with a signal corresponding to the light emission amount QVf. Based on the signals from both registers 21 and 22, the subtraction circuit 24 calculates BVa−TVs.
calculations are performed. Based on the data corresponding to the result of this calculation and the signal from the register 43, the subtraction circuit 44 performs the calculation Δ ₁ =QVf−(BVa−TVs) (1−4) to obtain the lighting contrast Δ ₁ is calculated. Also, if you specify the address of the ROM26 with data corresponding to the writing contrast Δ ₁ , the log ₂ (1+2 ^- 〓 ¹ ) stored in the ROM26 will be
The data corresponding to is read out. Based on this read data and the signals from the registers 23 and 24, the addition circuit 27 performs the calculation AVfa=QVf+SV+log ₂ (1+2 ^- 〓 ¹ )...(3) to determine the aperture value that provides the appropriate exposure.
AVfa is calculated. Figure 8 shows the aperture value in the configuration shown in Figure 6.
FIG. 4 is a block diagram of an arithmetic circuit 42 in a camera in which AVs are set. Then, based on the signals from the registers 23 and 43, the addition circuit 46 calculates AVf=QVf+SV (5). Based on the data corresponding to this calculation result and the signal from the register 45, the subtraction circuit 47 calculates Δ ₃ =AVs−AVf (6). If you specify the address of ROM48 with the data corresponding to this calculation result Δ ₃ ,
Data corresponding to log ₂ (1-2 ^- 〓 ³ ) stored in the ROM 48 is read out. On the other hand, based on the signals from the registers 23 and 30, the addition circuit 49 and the subtraction circuit 50 perform the calculation TVa=BVa+SV-AVs (8). Based on the data corresponding to this calculation result and the data read from the ROM 48, the subtraction circuit 51 performs the calculation TVx=TVa-log ₂ (1-2 ^- 〓 ³ )...(7-1). exposure time for proper exposure.
TVx is calculated. Furthermore, the subtraction circuit 52 and the subtraction circuit 53 calculate Δ ₁ =QVf-(BVa-TVx) (1-2) to determine the lighting contrast Δ ₁ . Figure 9 shows the aperture value in the configuration shown in Figure 6.
It is a block diagram of an arithmetic circuit 42 in a camera in which AVs and exposure time TVs are set.
Similarly to FIG. 7 above, the lighting contrast Δ ₁ is calculated from the subtraction circuit 47 and the flash amount AVfa is calculated from the addition circuit 27. Moreover, in FIG. 9, the above-mentioned Δ ₂ =AVs-AVfa is calculated by the subtraction circuit 34 based on the signal from the register 45 and the data from the addition circuit 27. As described above, the arithmetic circuit 42 shown in FIG. 6 automatically calculates the lighting contrast Δ ₁ based on the set light emission amount QVf of the strobe device 40 and displays it on the display device 8. Therefore, the photographer can easily recognize the lighting contrast _Δ1 before shooting. Note that when the configurations shown in FIGS. 1 and 5 are applied to the program shutter camera described above, the arithmetic circuit 3 has the circuit configuration shown in FIG. 2, and when the configuration shown in FIG. 6 is applied, the arithmetic circuit 42 The circuit configuration is shown in FIG. FIG. 10 is a block circuit diagram showing the basic configuration of a fourth embodiment of the present invention.
When both QVf and lighting contrast Δ ₁ are set, the brightness of the ambient light
Exposure time based on BVa, film sensitivity SV
It calculates both TVx and the aperture value AVfa that provides the appropriate exposure. That is, an analog signal corresponding to the set light emission amount QVf from the light emission amount setting circuit 41 of the strobe device 40 and an analog signal corresponding to the brightness BVa of the ambient light from the photometry circuit 1 are converted into digital signals by the A-D converter 46. It is converted into a signal and taken into the registers 43 and 21 in the arithmetic circuit 47. Also, the setting lighting contrast Δ ₁ from the setting device 2'
data and film sensitivity SV data are taken into registers 20 and 23, respectively. Then, the addition circuit 32 and the subtraction circuit 33 perform the calculation of TVx=Δ ₁ +BVa−QVf (1-3) to determine the exposure time to obtain the appropriate exposure.
TVx is collected, this data is input to the shutter control device 7 and the display device 8, and control and display are performed based on this data. On the other hand, data corresponding to the writing contrast Δ ₁ from the register 20 is sent from the ROM 26.
log ₂ (1+2 ^- 〓 ¹ ) is read out, and the adder circuit 48,
49, the following calculation is performed: AVfa=QVf+SV+log ₂ (1+2 ^- 〓 ¹ )...(3), and the aperture value for proper exposure is determined.
AVfa is calculated. Data corresponding to this aperture value AVfa is sent to the aperture control device 6 and the display device 8 for aperture control and display. Also,
In the strobe device 40, a signal corresponding to the light emission amount QVf from the setting device 41 and the output of the photometry circuit 4a are discriminated by the comparator 9a, and when they match, the light emission is stopped by the stop circuit 37 and the light emission amount is changed. QVf is controlled. FIG. 11 is a circuit configuration diagram of a circuit installed on the camera side of the first embodiment of the present invention. It is a single-lens reflex camera. Further, the calculation is performed in an apex system, each apex value is defined in Table 1, and the lower three bits are treated as a hexadecimal number as shown in Table 2. In other words, the minimum unit of the apex value is 1/6EV, so the upper 5 bits are the integer part of the apex value, and the lower 3 bits are 1/6EV.
It is the decimal part of the apex value whose minimum unit is 6EV. Moreover, lighting contrast Δ ₁ is 1/3
It shall be set in EV units, and for each Δ ₁
The value of log ₂ (1+2 ^- 〓 ¹ ) is shown in Table 3, and log ₂
Digital data “00H” corresponding to (1+2 ^- 〓 ¹ )
It is assumed that "28H" is stored in the ROM at an address specified by data corresponding to _Δ1 . In FIG. 11, PD ₁ is a photodetector;
E is a variable voltage source for adjustment, OA ₁ is an operational amplifier, D ₁
1 is a logarithmic compression diode, and these constitute the stationary light photometry circuit 1 shown in FIG.
Jo

【table】

【table】

【table】

【table】

【table】

[Table] shows the lighting contrast Δ ₁ set in the circuit installed in the strobe device 10, which will be described later.
This is a terminal for inputting analog signals corresponding to the . 100 is the signal and terminal from the above operational amplifier ₀ A ₁
A multiplexer that switches either the signal from J ₀ or the other based on the signal from terminal P14,
OA ₂ is a comparator for A-D conversion, 101 is D-
In the A converter, 102 is a hexadecimal counter, and 103 is a 32-decimal counter. 104 is both counters 102,1
This is a digital multiplexer that switches either the signal from the terminal P2 or the signal from the output port _F1 according to the signal from the terminal P2.
OA ₃ is an operational amplifier corresponding to the comparator 9 shown in Fig. 1, and J ₁ is the operational amplifier corresponding to the comparator ₉ shown in Fig. 1.
The terminal _J2 , which outputs a light emission stop signal to the strobe device 10 shown in the figure, is a terminal that outputs a light emission activation signal for the strobe device 10 in response to a signal from a switch _S6 , which is closed when the shutter is fully opened. _J3 is a terminal for connecting the strobe device 10 and the ground of the camera. Reference numeral 4 designates a photometry circuit that measures only the amount of light emitted from the strobe device 10 shown in FIG. 1, and is shown in detail in FIG. 12. That is, in Fig. 12, PD ₂ is a light receiving element installed at a position to receive the subject light reflected from the film surface during shooting, and OA ₄ is a voltage linear with respect to the output current of light receiving element PD ₂ . is an operational amplifier that outputs 105 is a high-pass filter consisting of capacitors C ₁ and C ₂ , resistors R ₁ and R ₂ , and an operational amplifier OA ₅ , which filters the output voltage of the operational amplifier OA ₄ to the strobe device 1.
It is designed to extract only the 0 emission component.
106 is a voltage-current conversion circuit consisting of an operational amplifier OA ₆ , a variable resistor VR ₁ , and a transistor BT ₀ , and the output current is adjusted by the variable resistor VR ₁ . 107 are diodes D ₂ connected to the collector of the transistor BT ₁ ,
A logarithmic compression integration circuit consisting of D ₃ and capacitor C ₃ .
As shown in Japanese Patent Publication No. 50-28038, a voltage is generated between the terminals of capacitor _C3 by integrating the inflow current and logarithmically compressing the integrated value. (FT) is an N-channel FET for discharging the capacitor _C3 , _S10 is a switch linked to the switch _S6 , and _OA7 is a buffer consisting of an operational amplifier.
Its output is applied to the operational amplifier _OA3 . Therefore, when the switch S10 is closed at the time when the strobe device ₁₀ starts emitting light, the N-channel FET (FT) becomes non-conductive, and the capacitor _C3
charging becomes possible. Then, a voltage signal corresponding only to the light emission component of the strobe device 10 output from the high-pass filter 105 is transmitted to the transistor BT ₀
The current is converted by the current and charged to the capacitor _C3 via the transistor _BT1 . this capacitor
The voltage across the terminals of _C3 is input to the plus terminal of the comparator OA ₃ , and at the point when it becomes equal to the voltage at the minus terminal, the output from the comparator OA ₃ is inverted from "L" to "H", and this " Based on the H'' signal, the strobe device 10 stops emitting light. Again, in FIG. 11, 7 is the shutter control device shown in FIG. 1, which is shown in detail in FIG. 13. That is, in FIG. 13, DE ₀ , DE ₁ are decoders, AN ₀ , AN ₁ . . . AN ₅ are AND circuits,
108 is a differentiation circuit consisting of a capacitor C ₄ and a resistor R ₃ ; CO ₀ , CO _{1 .} . . CO ₅ is the above-mentioned AND circuit AN ₀ ,
AN ₁ ...A counter provided corresponding to AN ₅ .
Counter CO ₀ outputs one output pulse for every 100 input pulses. Also, the counter
From CO ₁ there is one output pulse for every 89 input pulses, from counter CO ₂ there is one output pulse for every 79 input pulses, and from counter CO ₃ there is one output pulse for every 79 input pulses. One output pulse is output for each output pulse. Furthermore, counter CO ₄ outputs one output pulse for every 63 input pulses, and counter CO ₅ outputs one output pulse for every 56 input pulses. In other words, depending on the fractional part of the apex value of the exposure time TVs, the frequency division ratio of the input clock pulse Cp is 2 ⁰ : 2 ^{- 1/6} : 2 ^{- 2/6} : 2 - ^4/6 : 2 ^5/6 ≒
It is 100:89:79:71:63:56. CO ₆ is an OR circuit for the above counters C ₀ , C ₁ ... C ₅
OR is a presettable down counter connected via an AND circuit AN ₆ , its preset input terminal is connected to the output terminal of the decoder DE ₁ , and its inverted output terminal is connected to an AND circuit AN 7 via an AND circuit 7. Connected to ₈ . 109 is a differential circuit,
N is an inverter. L ₁ is transistor BT ₂
When coil _L1 is energized, the iron core inside the plunger moves against the spring force and the shutter closes. Further, when the current to the coil _L1 is cut off, the iron core is held in a predetermined position by the spring force, and the shutter opens. Therefore, when the terminal P14 is now inverted from "L" to "H", the counters CO ₀ , CO ₁ , . . . CO ₅ , CO ₆ are reset by the differential signal from the differential circuit 108. As a result, all the inverted output terminals of counter CO ₆ become "H", and the AND circuit
The output of AN ₇ becomes "H", and as mentioned above, the terminal P14 is also "H", so the output of AND circuit AN ₈ also becomes "H", and the coil _L1 is energized and the shutter is closed. Next, when the terminal P16 is inverted from "L" to "H", the signal from the decoder _DE1 is preset by the differential signal from the differentiating circuit 109. As a result, all the inverted outputs of counter CO ₆ are “H”
The output of the AND circuit _AN8 becomes "L", the current to the coil _L1 is cut off, and the shutter opens. Here, the data preset in the counter CO ₆ is the input signal F ₆ ' to the decoder DE ₁ , that is,
When the integer part of the apex value of the exposure time TVS is "10000", the least significant bit is "1" and the other bits are "0". Also, “01111”
When , the second bit from the bottom is “1” and the other bits are “0”, and when it is “01110”, the third bit from the bottom is “1” and the other bits are “0”, “00001”.
When , the most significant bit is "1" and the other bits are "0". Therefore, the counter
The data preset to CO ₆ is the exposure time TVs.
If the integer part of the apex value of is n (-5n10), it corresponds to ^210-n . Also, when the content of data F ₆ ″ corresponding to the decimal part is “000”, the gate of AND circuit AN ₀ is opened, when it is “001”, AND circuit AN ₁ is opened, and when it is “010”, AND circuit AN ₂ is opened. ,
At "011", AND circuit AN ₃ is opened, at "100", AND circuit AN ₄ is opened, and at "101", AND circuit AN ₅ is opened. Then, when the terminal P16 becomes "H", a clock pulse Cp is output from any one of the AND circuits AN ₀ , AN ₁ . . . AN ₅ ,
Exposure time starts from the time when terminal P16 becomes “H”
TVs count begins. Now, here, the frequency of the clock pulse Cp is f ₀ (=102, 4KHz), t
(=100, 89, 79, 71, 63, 56), time T
is given by T=1/f ₀ ×2 ^10-n ×r. When this time T has elapsed, all the inverted output terminals of the counter CO ₆ become "H", the output of the AND circuit AN ₈ becomes "H", the coil L ₁ is energized, and the shutter is closed and exposed. ends. Note that when the AND circuit AN ₇ becomes "H", the output of the inverted IN becomes "L", the gate of the AND circuit AN ₆ is closed, and the clock pulse Cp is no longer input to the counter CO ₆ , and , terminal P1
4. When P16 is set to "L", the shutter is opened again. Furthermore, when the shutter is opened for the first and last time, the reflecting mirror and the auxiliary shutter are down, as will be described later, so that no exposure is performed on the film surface. Again, in FIG. 11, 6 is the aperture control device shown in FIG. 1, which is shown in detail in FIG. 14.
That is, in FIG. 14, 110, 111,
112 is an operating member and a pair of contact pieces that constitute a pulse generation mechanism that outputs a clock pulse Cp when the aperture mechanism is in operation, CO ₇ is a hexadecimal counter, CO ₈ is a decimal counter, DC is a digital comparator, and 113 is a capacitor. It is a differentiating circuit consisting of C ₆ and resistor R ₅ . OS is a one-shot multivibrator (hereinafter simply referred to as one-shot circuit) circuit, and its output is applied to one input terminal of AND circuit _AN9 . L ₂ is a plunger coil connected to the collector of transistor BT _3. When energized, the iron core moves against the spring force and the diaphragm mechanism is narrowed; when energized, the spring force tightens the throttle mechanism. The iron core is held in place and the throttling mechanism is opened. _L3 is a magnet coil whose core is made of a permanent magnet and which locks the narrowing operation of the narrowing mechanism. Therefore, it is assumed that data obtained by subtracting "18H" from the data corresponding to the calculated aperture value is now output from output port _F7 . The reason for subtracting "18H" here is that, as is clear from the definition of aperture value AV in Table 1 above, the data is "00011000",
In other words, it is increased by "18H". Then, when the terminal P18 becomes "H", the counters CO ₇ and CO ₈ are reset by the differential signal from the differentiating circuit 113, and furthermore, the coil L ₂ is energized and the aperture mechanism starts operating, and is linked to this operation. Then, the operating member 111 moves on the contact pieces 110 and 112, and the clock pulse Cp is applied to the counters CO ₇ and CO _{8 .}
added to. When the data from the counters CO ₇ and CO ₈ match the data from the output port F ₇ , an “H” signal is output from the digital comparator DC, and the magnet coil L ₃ is energized to lock the diaphragm operation. Then, the aperture of the aperture mechanism is determined to correspond to the data from the output port _F7 .
When the terminal P18 is set to "L", the current to the coil _L2 is cut off, and the aperture by the aperture mechanism is opened by the spring force. Again, in FIG. 11, 113 is a drive circuit that drives the reflection mirror and the auxiliary shutter;
It has the same structure as the plungers L ₁ and L ₂ explained in FIGS. 3 and 14, and when the terminal P20 is "H", the reflecting mirror goes up and the auxiliary shutter opens.
When the position is "L", the reflecting mirror is lowered and the auxiliary shutter is closed. S ₁ is a switch that closes when the release button is pressed down in the first step, S ₂ is a switch that closes in the second step when the release button is pressed down, and S ₃ is a switch that closes on the terminal A side when shooting with aperture priority. During priority shooting, this is a switch connected to the terminal T side. Also, S ₄ is a switch that is closed when shooting is performed with the set aperture value AVs and the set exposure time TVs, and S ₅ is a switch that is closed when the exposure control preparation operation is completed and the exposure control operation is completed. This is a switch that is closed until 114 is a data output device corresponding to the film sensitivity SV, 115 is a data output device corresponding to the set exposure time TVs, and 116 is a data output device corresponding to the set aperture value AVs. 117 is the calculated light emission amount of the strobe device 10
A display device 118 displays the QVf, and a display device 118 displays the difference between the calculated exposure control value and the set exposure control value. 120 is a microcomputer, 121 is a CpU section of the microcomputer 120, and there are 8-bit general-purpose registers #OR and #1R inside.These registers #OR and #1R are connected in series to form a 16-bit register #. As 0PR, ROM12 described below
2 can be used for addressing. In addition to the above configuration, the CpU unit 121 includes an ALU, a program counter, an instruction decoder, an accumulator, a flag, a timing controller, etc., but these are not directly relevant to the explanation of this invention and will be omitted for simplicity. 122 is a ROM in which the operating program and constant data of the microcomputer 120 are stored;
3 is a RAM for temporarily storing data, and 124 is an I/O port. Next, FIG. 15 is a circuit configuration diagram of a circuit installed on the strobe device 10 side, where E ₀ is the power battery of the strobe device 10, S ₇ is the power switch, and 13
0 is a booster circuit, _D4 is a reverse current prevention diode,
_C7 is the main capacitor for voltage maintenance, and Ne is the neon tube. S ₈ is a switch linked to power switch S ₇ , Xe
is a xenon tube, ₁₃₁ is a trigger circuit _for the xenon tube be. VR ₂ is a potentiometer for lighting and contrast settings, and J ₀ ′, J ₁ ′, J ₂ ′, and J ₃ ′ are terminals connected to the corresponding terminals J ₀ , J ₁ , J ₂ , and J ₃ on the camera side, respectively. It is. Note that I ₀ is a constant power supply, BT ₅ , BT ₆ ...
...BT ₈ is a transistor, SC ₁ and SC ₂ are thyristors. Therefore, if you close switch S ₇ now,
When the booster circuit 130 is activated and the charging voltage of the capacitor C ₇ reaches a predetermined value, the neon tube Ne lights up and the transistors BT ₅ and BT ₆ become conductive. As a result, a voltage corresponding to the set lighting contrast Δ ₁ outputted by the potentiometer VR ₁ and the constant current source I ₀ is applied to the camera side. When trigger switch S ₆ on the camera side is closed, the emitter of transistor BT ₇ is connected to ground.
When the neon tube Ne is lit, the transistor
BT ₇ and BT ₈ are conductive, thyristor SC ₁ is also conductive, and the trigger circuit 131 causes the xenon tube Xe,
Thyristor _SC2 becomes conductive and starts emitting light. Then, when a light emission stop signal is input from the camera side,
The output terminal of the light emission stop circuit 132 becomes lower than the ground potential, and the xenon tube Xe stops emitting light. Next, when you open the power switch S ₇ , the switch S ₈
At this time, even if the charging voltage of the capacitor _C7 is sufficient for light emission, the neon tube Ne is turned off and the transistors _BT5 , _BT6 ... _BT8 are no longer conductive, and the lighting contrast Δ The signal corresponding to ₁ is not output, and the xenon tube
Nor is Xe emitted. The operation of the above configuration is shown in Figs. 16, 17, and 1.
This will be explained with reference to the flowcharts shown in FIGS. 8 and 19. First, when the camera is powered on, a power-on clear signal is input to the microcomputer 120, the entire microcomputer 120 is reset to its initial state, and starts operating. Then, in step #1, wait for switch S ₁ to close, switch S ₁ is closed and terminal P is
5 becomes "H", then in steps #2 and #3, terminals P4 and P2 are set to "H", the multiplexer 100 outputs the signal from the operational amplifier OA ₁ , and the multiplexer 104 outputs the signal from the counter 102, 103 data is input. Next, in step #4, set the terminal P0 to "H",
Next, in step #5, the counters 102 and 103 are reset by setting them to "L". Therefore, at this point, the output of the comparator _OA2 is "H". Subsequently, in step #6, the terminal P1 is set to "H", and in step #7, it waits for the output of the comparator _OA2 to be inverted, that is, for the terminal P16 to become "H". At step #8, when the terminal P1 becomes "H", the gate of the AND circuit _AN10 is opened, and the 6
A clock pulse Cp begins to be input to the advance counter 102. Then, one pulse is input to the counter 103 for every six clock pulses Cp. The outputs from the counters 102 and 103 are applied to the DA converter 101 via the multiplexer 104, and the DA converter 101 outputs analog signals corresponding to the output data of the counters 102 and 103. Ru. And multiplexer 10
When the output signal matches 0, the comparator
The output of OA ₂ is inverted and the gate of AND circuit AN ₁₁ is closed, i.e. the A-D of the photometric value of the stationary light.
Conversion ends. At this time, the output data of the counter 103 is the integer part of BVa, the counter 102
The output data is a decimal part whose minimum unit is 1/6 EV. On the other hand, the microcomputer 120 has a terminal
Set P ₁ to “L”, then in step #9,
The measured value BVa of the steady light from input port _F2 is A-
The D-converted data is stored in address _M1 of the RAM 123. Next, in step #10, it is determined whether the contents of address _M1 are in the BVa area defined in Table 1, that is, 08H or more and A8H or less, and if it is within this area, #1 If it is outside this area, go to step #11.
For example, the warning behavior of step #11 is as follows:
If it is too bright, the fixed data necessary to display “〓〓” in the segment is transferred from the ROM 122 to the CPU.
121 and sends this data to output port F ₈
You can output it to . Also, if it is too dark, just output the fixed data necessary to display the segment "〓〓" to output port _F8 , and then return to the start. In step #12, the terminal P4 is set to "L", and the multiplexer 100 outputs an analog signal corresponding to the set writing contrast _Δ1 from the terminal _J0 . Next, #12,
In steps #13, #14, #15, #16 and #17, the same A-D conversion operation as described above is performed. Then, in step #18, data corresponding to the lighting contrast Δ1 from input port _F2 is stored in address _M2 of the RAM 123, and in step #19, the data corresponding to the lighting contrast _Δ1 from input port _F3 is stored.
Data corresponding to the SV is stored at address _M3 of the RAM 123. Here, the film sensitivity SV data is in units of 1/3 EV. Next, in step #20, the RAM123
Determine whether the contents of address _M2 are greater than or equal to A8H,
If it is not A8H or above, the normal shooting operation starts from step #63. In steps #21 and #22, the status of switches S ₃ and S ₄ is determined, and when the mode is in aperture priority mode, the process moves to step #23 and data corresponding to the set aperture value AVs from input port F ₅ is input. Store in address _M5 of RAM 123. At step #24, data corresponding to the writing contrast _Δ1 stored at address _M2 of the RAM 123 is taken into register #1R, and at step #25, a constant _K1 is set in register #0R.
At step #26, in 16-bit register #0PR
Specify the address of ROM122 and log ₂ (1+2 ^- 〓 ¹ ) shown in Table 3 above is fixedly stored there.
Set the data corresponding to to register #0R.
Next, in step #27, the following calculation is performed: QVf = AVs - SV - log ₂ (1 + 2 ^- 〓 ¹ ) + AOH (4). The calculation method here is performed separately for the upper 5 bits and the lower 3 bits. Then, for the top 5 bits, each bit has 1, 2, 4, 8,
When performing weighting of 16, A0H is added as shown in the definition in Table 1, and the calculation is performed in such an order that the data does not become negative during the calculation. Here, for example, AVS is 5 (40H), SV is 5 (30H),
If the integer part of log ₂ (1+2-Δ ₁ ) is 1 (08H), the light emission amount QVf should be 1, that is, A8H. Therefore, first, A0H-30H=70H is calculated, then 70H-08H=68H, and then 68H+40H=A8H. On the other hand, the lower 3 bits are calculated as hexadecimal numbers. For example, to subtract "100" from "010", first,
Since “010” is smaller, 1 is subtracted from the top 5 bits of data, “100” is subtracted from “110”, and the result is added “010” and “010”.
Calculate “100”. That is, this calculation corresponds to performing the calculation of m2/6-4/6=(m-1)4/6, where m is an integer. Similarly, when adding, compare the addition result and the size of "110",
If it is “110” or more, add 1 to the top 5 bits,
The value obtained by subtracting "110" from the result becomes the decimal part data. That is, it is sufficient to perform the calculation m5/6+4/6=(m+1)3/6. All of the above calculations are performed in the same manner. In step #28, it is determined whether the calculated light emission amount QVf is within the range shown in Table 1 above. If it is outside the range, in step #29, a warning is issued on the display device 117 and the process returns to the start. When it is within the range, in step #30, the data necessary to display the light emission amount QVf in segments using the apex value is output to the output port _F9 . Next, in step #31, the following calculation is performed: TVx=Δ ₁ +BVa−QVf−30H (1-3). At step #32, it is determined whether the calculation result is within the control range defined in Table 1. If it is outside the range, at step #33, a warning is issued on the display device 118 and the process returns to the start. Next, if it is within the control range, as shown in Figure 17, in step #34, the exposure time for the proper exposure is set.
TVx is displayed on display device 118. This display method, for example, outputs the segment data stored at the address of the ROM 122 corresponding to the upper 5 beat data to the output port _F8 in step #34, and displays the exposure time (seconds) in IEV units. It is to be displayed. Next, in step #35, the exposure time TVx that is the calculated appropriate exposure is output to output port _F6 , and in step #36, the aperture value is
Output AVs to output port _F7 . Here, the data output to the output port _F7 is the data obtained by subtracting "18H" from the data corresponding to the aperture value AVs, as shown in FIG. Next, in step #37, change the aperture value from the light emission amount QVf.
The data after subtracting AVs is output to the output port _F1 , and in step #38, the terminal P2 is set to "L", and the analog signal corresponding to RVf-AVs is output from the DA converter 101. Move on to step #85. If it is determined in steps #21 and #22 that exposure time priority shooting or manual setting shooting is being performed, the process moves to step #39. In step #39, data on the set exposure time TVs from input port _F4 is written to address _M4 of the RAM 123, and then in step #40, data on aperture value AVs from input port _F5 is written to _{address M5} . Write in the address. Next, in step #41, the calculation QVf= _Δ1 +BVa-TVs-30H...(1-1) is performed, and then, in step #42,
It is determined whether the light emission amount QVf data is within the controllable range, and if it is outside the range, a warning is issued in step #43 and the process returns to the start. If it is within the range, step #44 displays the light emission amount QVf as an apex value, and step #45 displays the RAM 123.
The data corresponding to the lighting contrast _Δ1 stored at address _M2 is taken into register #1R, and in step #46, a constant _K1 is set in register #0R. At step #47, specify the address of ROM122 using register #0PR,
Set the data corresponding to log ₂ (1+2 ^- 〓 ¹ ) in register #0R. Next, in step #48, calculate AVfa = QVf + SV + log ₂ (1 + 2 ^- 〓 ¹ ) - A0H...(3), and in step #49, connect terminal P1.
2 is an "H" signal or an "L" signal.
When the terminal P12 is "H", it is the manual setting mode, and in this case, in step #50, the difference _Δ2 between the calculated aperture value AVfa and the set aperture value AVs is displayed on the display device 118 as an apex value. indicate. Next, in step #51, output the exposure time TVs to port _F6
to the port that outputs the aperture value AVs in step #52.
QVf−AVs at step #53 to F ₇
is output to the output port _F1 , and at the same time, the terminal P2 is set to "L" in step #54, and the process moves to step #85. In step #49, when terminal P2 is "L", it is the exposure time priority mode, and in this case, the process moves to step #55, and in step #55, the calculated aperture value AVfa is within the controllable range. If it is out of the controllable range, a warning is issued on the display device 118 in step #56, and the process returns to the start. If it is within the range, display the aperture value AVfa on the display device 118 in step #57,
At step #58, data corresponding to the aperture value AVfa is output to the aperture control device 6. Also, in step #59, the exposure time TVs is output to the shutter control device 7, in step #60, QVf-AVs is output to the output port _F1 , and in step #61, the terminal P22 is set to "L". Move to step 85. The discrimination result in step #20 mentioned above is
When not using strobe photography according to this invention, the first
As shown in FIG. 8, normal apex calculation and display are performed by proceeding to step #62 and following step #84. In other words, when shooting with manual settings, each step from step #64 to #70 calculates the exposure value EVs based on the set exposure time TVs and the set aperture value AVs, and the set film sensitivity. The difference Δ ₃ between the SV and the exposure value EVa calculated based on the photometric value BVa = EVs - EVa is displayed, and the set exposure time control data and the set aperture value control data are output. Move on to the next step. When performing aperture-priority shooting, the calculated exposure time control data and the set aperture control data are output in each step from step #63 to #77, and the process moves to step #85. Furthermore, during exposure time priority shooting, the calculated aperture value AVa is displayed in each step from step #63 to #84, and the calculated aperture control data and the set exposure time control data are output. This is shown in FIG. Move on to step #85. In step #85, the state of terminal P8 is determined, and if it is "L", the release button has not been pressed down to the second step, so the process returns to the start.
When it is "H", the state of terminal P24 is then determined in step #86. When this terminal P24 is "L", the camera remains in the same state as when the photographing operation was completed, and cannot shift to the exposure control operation, so it returns to the start. When the terminal P24 is "H" in step #86, the film is being wound and preparations for exposure control are being made, so the process moves to steps #87 and subsequent steps and shifts to exposure control operation. . That is, in step #87, the terminal P14 is set to "H" to start the operation of the shutter control device 7 to start the shutter closing operation, and then,
At step #88, terminal P18 is set to "H" to start the aperture control device 6's aperture operation, and step #89
Count the time of T ₁ in step . During this time, the aperture aperture by the aperture control device 6 is determined based on the data from the output port _F7 . Next, in step #90, the terminal P20 is set to "H" to drive the drive circuit 113 to raise the mirror and open the auxiliary shutter. Next, in step #91, the time T ₂ is counted, during which time the mirror is fully raised and the auxiliary shutter is also fully opened. Next, the terminal P16 is set to "H" to operate the shutter control device 7 to open the shutter and start counting the exposure time TVs. When the shutter reaches its maximum opening, the switch _S6 closes and the strobe device 10 emits light in an amount based on the control data. Next, the exposure time count is finished,
In step #93, when the terminal P22 becomes "H", the shutter control device 7 closes the shutter. Next, in step #94, terminal P20 is set to "L" to drive the drive circuit 113, the mirror is lowered, and the auxiliary shutter is closed. Next, in step #95, terminal P18 is set to "H" to set the aperture. Open,
At step #96, count the time of _T3 . During this time, the aperture is stopped, the mirror auxiliary shutter returns to its original state, and then in step #97, the terminal P
14, P16 is set to “L” and shutter control device 7
Open the shutter and step #98, T ₄
Count the time. During this time, the shutter is completely opened, and the shutter returns to the start. If the release button is pressed down, photometry and calculation display operations are performed. Note that when switch _S2 is closed, the signal at terminal P8 is transmitted to display devices 117 and 118.
In addition, it is desirable to deactivate the display devices 117, 118. As described above, according to the first invention and the second invention, the amount of flash light emission can be controlled based on the lighting contrast set in the flash light emitting device or the camera; According to the invention, the lighting contrast corresponding to the set amount of light emission can be displayed, and the flash light emitting device can be caused to emit light by the set amount of light emission. Therefore, it is possible to easily perform flash photography that takes into consideration the lighting contrast between steady light and flash light emission.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram showing a first embodiment of the basic principle of this invention, and FIGS. 2, 3, and 4 are
FIG. 1 is a block circuit diagram showing the specific configuration of the arithmetic circuit, FIG. 5 is a block circuit diagram showing a second embodiment of the basic principle of the invention, and FIG. 6 is a block circuit diagram showing the basic principle of the invention. FIGS. 7, 8, and 9 are block circuit diagrams showing the third embodiment, and FIG. 10 is a block circuit diagram showing the specific configuration of the arithmetic circuit shown in FIG. A block circuit diagram showing the fourth embodiment of the basic principle, FIG. 11 is a specific circuit diagram on the camera side of the first embodiment of the invention shown in FIG. 1, and FIG. 13 is a detailed circuit diagram of the photometry circuit, and FIG. 14 is a detailed circuit diagram of the shutter control device shown in FIG. 11.
The figure is a detailed circuit diagram of the aperture control device shown in Figure 11, Figure 15 is a circuit configuration diagram of the circuit provided in the strobe device, Figures 16, 17, 18, and 19.
The figure is a flowchart showing the operation of the configuration shown in FIG. 1...Photometering circuit, 2...Exposure control value setting device,
3... Arithmetic circuit, 4... Photometry circuit, 5... Signal conversion circuit, 6... Aperture control value, 7... Shutter control device, 8... Display device, 9... Comparator, 1
0... Strobe device.

Claims (1)

[Scope of Claims] 1. A photometry circuit that measures ambient light and an output device that outputs a signal according to a set exposure time, and that is capable of adjusting the amount of contribution of ambient light to photography and the amount of contribution of flash light to photography. an output device that outputs a signal corresponding to a lighting contrast defined as a ratio; and a contribution to flash photography that is required based on signals from the lighting contrast output device, the photometry circuit, and the exposure time output device. Exposure for flash photography characterized by comprising an arithmetic circuit that calculates the amount of light, and a control circuit that controls the amount of flash light emission based on a signal from the arithmetic circuit and a signal corresponding to the amount of light reflected from the subject of the flash. Control device. 2. Equipped with a photometry circuit that measures ambient light, and an output device that outputs a first signal according to the set film sensitivity and a second signal according to the set aperture value, and
Lighting is defined as the ratio of the contribution of steady light to photography and the contribution of flashlight to photography.
an output device that outputs a signal corresponding to contrast; a signal corresponding to an exposure time for appropriate exposure based on signals from the lighting/contrast output device, the photometric circuit, and the film sensitivity and aperture value output device; An arithmetic circuit that calculates a signal corresponding to the amount of contribution of the flash to photography; and a calculation circuit that calculates the amount of flash light emitted based on a signal from this calculation circuit that corresponds to the amount of contribution of the flash to photography and a signal corresponding to the amount of light reflected from the subject of the flash. 1. An exposure control device for flash photography, comprising: a control circuit for controlling a shutter according to a signal corresponding to an exposure time; 3. A setting device that is equipped with a photometry circuit that measures ambient light and an output device that outputs a signal according to a set exposure time, and that sets the amount of contribution of flash light to photography, and this flash contribution amount setting device and the above-mentioned photometer. an arithmetic circuit that calculates a lighting contrast defined as a ratio between the amount of contribution of steady light to photography and the amount of contribution of flash light to photography based on signals from the circuit and the output device; and based on the signal from this arithmetic circuit. a display device that displays the lighting contrast, and a signal that corresponds to the amount of flash light that contributes to photography set in the flash contribution amount setting device and a signal that corresponds to the amount of light reflected from the subject of the flash light, and the amount of flash light emitted is determined based on the signal that corresponds to the amount of light reflected from the subject. 1. An exposure control device for flash photography, comprising a control circuit for controlling the exposure. 4. Equipped with a photometry circuit that measures ambient light, and an output device that outputs a first signal according to the set film sensitivity and a second signal according to the set aperture value, and
A setting device for setting the amount of contribution of flash light to photography, a signal corresponding to an exposure time for a proper exposure based on signals from the flash contribution amount setting device, the photometry circuit, and the output device, and photography of ambient light. an arithmetic circuit that calculates a lighting contrast defined as a ratio of a contribution amount to a contribution amount to that of the flash light and a contribution amount to the flash light photography; a display device that displays the lighting contrast based on a signal from the arithmetic circuit; Controls the amount of flash light emission based on a signal corresponding to the amount of contribution of flash light to photography set in the setting device and a signal corresponding to the amount of reflected light from the subject of the flash light, and also corresponds to the exposure time calculated by the above calculation means. 1. An exposure control device for flash photography, comprising: a control circuit for controlling a shutter according to a signal transmitted from the shutter.