JPS642929B2 - - Google Patents

Description

[Detailed description of the invention] Technical field The present invention relates to a photometric device for flash photography.

Prior Art In conventional photometering devices for flash photography, once an exposure time is set, photometry is continued for the set exposure time, and an appropriate aperture value is obtained using the integrated light amount during this time. Therefore, in such an apparatus, when the exposure time is set to a long time, it is necessary to hold the photometer at a fixed position during the exposure time, and furthermore, there is a drawback that photometry takes time.

In addition, with the conventional photometer for flash photography mentioned above, when the set exposure time is changed, the amount of flash light is switched, or the ambient light changes, the flash must be fired again to obtain the appropriate aperture value. It was necessary to perform photometry.

Furthermore, Special Publication No. 47-2756, Special Publication No. 47-2756,
According to Publication No. 4088 and Japanese Patent Publication No. 47-4089, the photometric output during flash emission is divided into a steady light component and a flash component using a high-pass filter, and the effect of the steady light is also taken into consideration. Although a device for controlling the amount of light emitted has been proposed, it is impossible to obtain data on the aperture value with this device.

Furthermore, since conventional photometering devices do not have the concept of measuring ambient light and flash light separately, no device has yet been proposed that measures and displays the light amount of flash light alone, and furthermore, the appropriate aperture for the light amount of flash light alone has not been proposed. There is also no proposal for calculating and displaying values.

Furthermore, no device has been proposed that calculates and displays the lighting contrast during flash photography, that is, a value corresponding to the ratio of the amount of light due to steady light and the amount of light due to flash only during the exposure time.

Furthermore, it calculates and displays a value corresponding to the ratio of the total light amount during the exposure time during flash photography to the light amount due to only steady light, and a value corresponding to the ratio of the total light amount to the light amount due to flash only. No device has been proposed to do so.

Conventionally, the various data mentioned above were calculated by the photographer himself by measuring the light once while the flash was firing, and then measuring the ambient light separately, based on these two light metering results and the setting values. Since the calculations were calculated by calculation, the operations were extremely complicated and time-consuming, and furthermore, the data could not be obtained by people who did not know how to calculate the data.

Purpose/Summary of the Invention The present invention was made with the aim of improving the various drawbacks mentioned above.

This invention provides a first method in which the amount of flash light received is related only to the amount of light emitted by the flash light emitting device emitted in advance.
A second signal corresponding to the brightness of only the ambient light is obtained, and the appropriate aperture value for flash photography is calculated based on these two signals, the set exposure time, and the film sensitivity signal. We propose a photometering device for flash photography.

The present invention also proposes a new photometric device for flash photography that calculates lighting contrast during flash photography based on the first signal, the second signal, and the set exposure time signal.

Furthermore, the present invention calculates a value corresponding to the ratio of the total light amount to the light amount of only the steady light during flash photography based on the first and second signals and the set exposure time signal. We propose a new photometering device for flash photography.

Furthermore, the present invention provides a flash that calculates a value corresponding to the ratio of the total light amount during flash photography to the light amount of only the flash based on the first and second signals and a set exposure time signal. We propose a new photometering device for photography.

Further, since the present invention is provided with a change value setting device for setting a change value of the amount of flash light emitted, it is possible to obtain the above-mentioned various data when the amount of light emission is changed without performing photometry again.

In addition, the present invention performs calculations by repeatedly inputting signals corresponding to the brightness of the stationary light, signals corresponding to changes in the amount of flash light, signals corresponding to the set film sensitivity, and the set exposure time to the calculation circuit. It becomes possible to calculate the various data described above without causing the flash light emitting device to emit light again after changing the various signals described above and performing photometry.

Note that the value corresponding to the ratio that often appears here is, strictly speaking, the difference between the logarithmic compression values of two amounts of light.

Embodiment FIG. 1 is a circuit diagram showing an embodiment of the present invention. The constant current source I ₀ , the variable resistor VR ₀ , and the buffer OA ₀ are circuits for adjusting the photometric output when measuring only steady light. D ₀ is a logarithmic compression diode, PD is a photodiode, and R ₀ is a resistor that converts the output current of the photodiode PD into a voltage.

FT ₀ and FT ₆ are FETs that conduct during photometry of the amount of light emitted from the flashlight emitting device, and FT ₂ and FT ₄ are FETs that conduct during photometry of steady light. Capacitor C ₀ resistor R ₂ constitutes a high pass filter. operational amplifier
The circuit composed of OA ₄ , variable adjustment resistor VR ₂ , and transistor BT ₂ is a voltage-current conversion circuit. _BT2
are current mirror transistors and diodes
As shown in Japanese Patent Publication No. 50-28038, the circuit composed of D ₂ , D ₄ , and capacitor C ₂ integrates the inflow current and logarithmically compresses the integral value of the inflow current to the capacitor C. This is a circuit that outputs to both ends of ₂ . OA ₆ is a buffer, 10 is an analog multiplexer, 1 is an A-D converter, 12 is a digital multiplexer, 30 and 32 are registers in which data from the digital multiplexer 12 is set, and 20 is an exposure time setting. device, 2
2 is a film sensitivity setting device, and 24 is a flash light emission amount change value setting device. 4 is a setting device 20, 22,
24. Based on the data from registers 30 and 32, the flash light emission amount QVf', the appropriate aperture value AVf for only the flash light emission amount, and the appropriate aperture value for flash photography.
AVx, lighting contrast Δ during flash photography, contrast between areas illuminated with flash light and areas not illuminated during flash photography, or contrast log2 (1+2〓) between when flash light is illuminated and when not.
The details of the arithmetic circuit that calculates the data will be described later based on FIG. 50 to 58 are decoders that decode the data from the arithmetic circuit 4 into data necessary for display, 6 is a display device that displays the data from the decoders 50 to 58, 7 is a flash light emitting device, Xe is a xenon tube, and S ₀ is a photometer A switch 8 is closed when starting the operation, and 8 is a timing controller that controls the operation timing of each part of the circuit shown in FIG.
Specific examples of this circuit are shown in FIGS. 2, 3, and 4, and a timing chart of the operation is shown in FIG.

In Figures 2, 3, and 4, POR indicates the power-on reset signal output when the power is turned on, OS ₀ is a one-shot circuit, DI ₀ is a frequency divider, CO ₀ is a counter, and FF _{0 -FF10} is an R-S flip-flop, _TF0 to _TF16 are T flip-flops, _OR0 to _OR18 are OR circuits, and _AN0 to _AN40 are AND circuits. Also, the logic circuit in Figure 2
LU ₀ is shown in FIG. 3, and logic circuit LU ₂ is shown in FIG.

Next, the operations shown in FIGS. 1, 2, 3, and 4 will be explained according to the timing chart shown in FIG. First, when the power is turned on, the R-S flip-flops _FF0 to _FF10 , T flip-flops _TF0 to _TF16 , and counter _CO0 are reset by the power-on reset signal POR, and the R-S flip-flop _FF10 is set. . At this point, FETs FT ₀ and FT ₆ are non-conducting, and FT ₂ , FT ₄ and FT ₈ are conducting. Next, when the switch _S0 is closed, the terminal 800 becomes "high", and the one shot circuit is activated by this rising signal.
A “high” signal is output from OS ₀ for a certain period of time. This signal is transmitted to the R-S flip-flop _FF2 via the AND circuit _AN0 to set it. The Q output of this flip-flop FF ₂ is an AND circuit.
The gate of AN ₂ is opened, and the clock pulse output from the division period _{DI 0 is} output from the AND circuit AN 2. At the same time, the Q output of the flip-flop FF ₂ also opens the gate of the AND circuit AN ₈ . Flip-flop _FF8 is set at the rising edge of the first clock pulse Qa inputted via AND circuit _AN2 outputted from Flipflop _FF8 . This Q
The output is a signal terminal 802. This terminal 8
02 becomes “high”, the R-S flip
The flop FF ₀ is set and the output becomes “low”. From then on, while the photometry operation continues, even if the switch S ₀ is closed and a pulse is output from the one-shot circuit OS ₀ , the pulse will not be output from the AND circuit AN ₀ . Not done. When this terminal 802 becomes "high", FETs FT ₀ and FT ₆ shown in Fig. 1 become conductive, ET ₂ and FT ₄ become non-conductive, and the (+) terminal of operational amplifier OA ₂ is connected to ground. A resistor R ₀ is connected to the feedback path, and the output of the operational amplifier OA ₂ is connected to a capacitor.
C ₀ , the output of the multiplexer 10 becomes the potential from the buffer OA ₆ , and the demultiplexer 12 becomes ready to output data to the register 32 .

Q of T flip-flops TF ₀ to TF ₈ dividing the clock pulse from AND circuit AN ₂
Among the outputs, Qd, Qe, and Qf are "low" and at time _t2 when Qc rises to "high", the output of the AND circuit _AN16 rises to "high". With this signal, flip-flop _FF10 is reset and the Q output falls to "low". In addition, the T flip-flops TF ₀ to _{TF 8} are T flip-flops TF 0 to TF 8 as shown in FIG. 5 Qa to Qf.
Inverts the Q output at the falling edge of the input. The Q output of flip-flop FF ₁₀ becomes terminal 804,
When the terminal 804 falls, the flash light emitting device 7 starts emitting light, and at the same time, the FET and FT ₈ become non-conductive, and charging of the capacitor C ₂ starts. The operational amplifier OA ₂ outputs a potential equal to the value obtained by multiplying the constant light of the light receiving element PD and the photocurrent generated by the flash light emitting device 7 by the resistance value of the resistor _R0 , that is, a potential proportional to the photocurrent of the light receiving element PD. , capacitor C ₀ ,
From the high pass filter consisting of resistor R ₂ ,
Only the alternating current component of the output of the operational amplifier OA ₂ , that is, only the potential corresponding to the intensity of light emission from the flashlight emitting device 7 is output. The output of the high-pass filter is converted into a current by a voltage/current conversion circuit consisting of an operational amplifier OA ₄ , a transistor BT ₀ , and a resistor VR ₂ , and this current is passed through a transistor BT ₂ to a diode D ₂ and a capacitor D ₄ . C flows into a circuit made up of ₂ . Therefore, the voltage across the capacitor _C2 is a value obtained by logarithmically compressing the integral value of only the current of the light receiving element PD corresponding to the output current due to light emission from the flash light emitting device 7.

At time t ₃ , the combination of the Q outputs of the T flip-flops TF ₀ to _{TF 8} is such that QF, Qe, Qc are "high" and Qd is "low", which is the output of the AND circuit AN ₁₈ (Figure 3). 806' becomes "high", this signal is outputted to terminal 806 via OR circuit _OR10 (FIG. 2), and A/D converter 1 operates. At this time A-
Since the terminal 802 is "high", the input to the D converter 1 is the signal from the buffer OA ₆ , that is, the flash light emitting device 7.
It is the value obtained by logarithmically compressing the amount of light emitted by . Here, the time from time t ₂ to time t ₃ is longer than the light emission time of a commercially available flashlight emitting device, and therefore, after the flashlight emitting device finishes emitting light, there is no signal from the high-pass filter. There is no output, and no current flows through the transistor BT ₂ from the end point to the time t ₃ .

At t ₄ , the Q of T flip-flop TF ₂
Output Qc falls to "low", and this falling signal sets flip-flop FF ₁₀ through inverter IN ₂ and OR circuit OR ₁₆ , thereby causing terminal 804 to go "high". Therefore, FET,
FT ₈ conducts and discharges the charge on capacitor C ₂ . Further, when the terminal 806 becomes "low", the operation of the AD converter 1 ends, but at this point, the AD conversion has already ended.

At time t ₅ , T flip flop TF ₀ ~ _{TF 8}
The combination of Q outputs is Qf, Qe, Qd are “high” Qc,
Qb becomes "low" and the AND circuit _AN26 outputs the pulse Qa from the AND circuit _AN2 . The output of this AND circuit AN ₂₆ becomes a terminal 810, and data QVf corresponding to the logarithmically compressed value of the light emission amount of the flashlight emitting device 7 from the A-D converter is sent to the register via the demultiplexer 12 using the rising signal of the terminal 810. 32.

At time t ₆ , T flip flop TF ₀ ~ _{TF 8}
The combination of Q outputs is such that Qf, Qe, Qd, and Qb are "high" and Qc is "low," and the AND circuit AN ₃₀ outputs the flock pulse Qa output from the AND circuit AN ₂ . This rising signal d
The flip-flop _FF8 is reset and the terminal 802 becomes "low", and this signal d resets the flip-flop _FF2 and the AND circuit is reset.
After the gate of AN ₂ is closed, the clock pulse Qa is no longer output from the AND circuit AN ₂ . Furthermore, the flip-flop _FF4 is set by the signal d, and the Q output e becomes "high", and the gate of the AND circuit _AN4 is opened _.
The clock pulse Qg from the frequency divider DI ₀ is output from. Furthermore, the T flip-flops TF ₀ -TF ₈ are also reset by the signal d. Therefore, t ₆
From the point in time, FET, FT ₀ and FT ₆ become non-conductive,
FT ₂ and FT ₄ become conductive, the feedback path of operational amplifier OA ₂ is short-circuited, and it becomes a voltage follower type, and the output is generated by constant current source I ₀ output from buffer OA ₀ and adjustment resistor VR ₀ . The photodetector detects the potential created by
A potential is output that is the sum of the output current proportional to the brightness of the steady light of the PD and the potential logarithmically compressed by the diode _D0 . The output of this operational amplifier OA ₂ is a FET,
The signal is inputted via FT ₄ to a smoothing circuit configured by a resistor R ₄ and a capacitor C ₄ that removes the influence of fluorescent lights and the like. The output of this smoothing circuit is input to the multiplexer 10, and since the terminal 802 is "low", the signal from the smoothing circuit is output from the multiplexer 10. In addition, demultiplexer 12
Since the terminal 802 is “low”, the data from the AD converter 1 is output to the register 30. As described above, at time _t6 , the circuit of FIG. 1 switches from the mode of photometering flash light emission to the mode of photometering stationary light.

At t ₇ , T flip flop TF ₁₀ ~
The combination of the outputs of the TF ₁₄ is such that Qj is "low" and Qi is "high", and the AND circuit AN ₃₄ outputs a "high" signal. This becomes the output terminal 806'' of this AND circuit AN ₃₄ , and A- through the OR circuit OR ₁₀ .
It outputs a signal that causes the D converter 1 to operate.
This signal remains "high" until time _t8 .
Between time _t7 and time _t8 , the A/D converter 1 converts the analog signal from the multiplexer 10, which is proportional to the logarithm of the brightness of the stationary light, into a digital signal BVa.

At t ₉ , T flip flop TF ₁₀ ~
The combination of Q outputs of TF ₁₄ is Qj is "high", Qi is "low", and Qh is "low", which is an AND circuit from AN ₄₀ .
Pulse Qg from AN ₄ is output, which is connected to terminal 80.
It becomes 8. At the rising edge of this signal, register 3
0 contains data from demultiplexer 12.
BVa is taken in. At time _t10 , the combination of the outputs of the T flip-flops _TF12 and _TF14 is such that Qi and Qj are "high", and the output of the AND circuit _AN32 is "high". This output becomes a terminal 812, and a signal from this terminal 812 is sent to the arithmetic circuit 4, so that the arithmetic circuit 4 operates. This arithmetic circuit will be described later based on FIG.

At time _t11 , the Q output Qk of the T flip-flop _TF16 rises to "high", and this signal resets the flip-flop _FF4 and the T flip-flops _TF10 to _TF16 , so that the flip-flop
The Q output e of the flop FF ₄ becomes "low" and the Q outputs Qg to Qj of the T flip-flops TF ₁₀ to TF ₁₆ also become "low", the gate of the AND circuit AN ₄ is closed, and the clock pulse Qg is no longer output. .
Furthermore, the flip-flop _FF0 is reset, the Q output a becomes "high", and the gate of the AND circuit _AN0 is opened. Therefore, when the switch _S0 is closed and a pulse signal is output from the one-shot circuit _OS0 , the flash light emission photometry becomes possible again. Furthermore, the flip-flop is activated by the Qk signal.
FF ₆ is set, the gate of AND circuit AN ₆ is opened, and the clock pulse from frequency divider DI ₀ is input to counter CO ₀ via AND circuit AN ₆ . Further, the Q output of the flip-flop FF ₆ is connected to a terminal 814, and the signal from this terminal is sent to the display device 6, and the output data of the arithmetic circuit 4 is transferred to the decoders 50 to 814.
The display device 6 performs a display based on the data decoded into display data by the display device 58.

Display is carried out for a certain period of time, and when the carry terminal _Q1 of the counter _CO0 rises to "high" at time _t12 , the counter _CO0 and flip-flop _FF6 are reset by this signal. Therefore, terminal 814
falls to "low" and no display is performed. Also, flip-flop _FF0 is set, and terminal a becomes "low", closing the gate of AND circuit _AN0 . Further, the flip-flop _FF4 is set and the terminal e becomes "high", and the AND circuit _AN4 again outputs the clock pulse Qg. Therefore, the above-mentioned photometric calculation operation for steady light is again performed.
This continues until time t ₁₇ , and the display is performed after t ₁₇ .

As mentioned above, the circuit in Figure 1
The flash light emitting device 7 with S ₀ closed emits light, measures only the amount of light emitted, converts this photometric value into a digital value QVf and stores it in the register 32, and then converts the photometric value of the ambient light into a digital value BVa. The photometric data is converted into the data and taken into the register 30, calculations are performed based on the photometric data, and a display is performed based on the calculation results. Then, from now on, A-D conversion of stationary light,
Calculation and display are repeated, and when the switch is closed during the display period, the operation from photometry of the amount of flash light emission is performed again. In addition, the constant light A
When switch _S0 is closed during -D conversion or calculation, in order to shift to the flash side light mode after the calculation is completed, terminal e must be set during the period when the output of one-shot circuit _OS0 is "high". It is sufficient to make the period longer than the “high” period. In other words, even if switch _S0 is closed while terminal e is "high",
When the terminal e becomes "low", the gate of the AND circuit AN ₀ is opened, and the output of the one-shot circuit OS ₀ is still "high", so the output 6 of the AND circuit AN ₀ goes "high" and the flip-flop
After setting FF ₂ , the above-mentioned photometry operation for the amount of flash light emission is performed.

Next, the calculation operation will be described based on FIG. Data QVf obtained by logarithmically compressing the flash light emission amount from the register 32 and data Δf from the light emission amount change value setting device 24 are input to the addition/subtraction circuit 40.
When Δf is positive, QVf + | Δf | = QVf′, and when Δf is negative, calculate QVf − | Δf | = QVf′.
The data of QVf' is sent to a decoder 52, an adder circuit 41,
It is output to the subtraction circuit 43. Here, the input bits of Δf are such that, for example, the most significant bit indicates positive or negative, and the other bits indicate absolute values. The adder circuit 41 outputs data QVf obtained by logarithmically compressing the amount of flash light output from the adder/subtracter circuit 40 and the film sensitivity setting device 2.
Input the data SV from 2, QV′f+SV=
Performs AVf calculation. That is, an appropriate aperture value is calculated for only the amount of flash light emitted. This data is output to decoder 50.

The data BVa obtained by logarithmically compressing the brightness of the stationary light from the register 30 and the exposure time data TVs from the exposure time setting device 20 are input to the subtraction circuit 42, and the calculation of BVa-TVs is performed. That is,
Data obtained by logarithmically compressing the amount of constant light during the set exposure time is obtained. This data is input to a subtraction circuit 43 and an addition circuit 45. The subtraction circuit 43 inputs the data QV'f from the addition/subtraction circuit 40 and the data from the addition circuit 42 and performs the calculation QVf'-(BVa-TVs)=Δ. In other words, the amount of light due to constant light during the set exposure time 2 _Bva-TVs and the amount of light due to only the amount of light emitted from the flash
2 Calculate the value (lighting contrast) Δ corresponding to the ratio of _QVf ′. This data is sent to the decoder 56
is output to the ROMs 44 and 46. As for the output bits of this data, for example, the most significant bit is a signal indicating whether Δ is positive or negative, and the other bits are signals indicating the absolute value of Δ.

When an address is designated by the data Δ corresponding to the writing contrast from the subtraction circuit 43, the OOM 44 outputs log ₂ (1+2〓) data corresponding to the address designation data Δ previously stored therein. . This log ₂ (1 + 2〓) is the total amount of light from constant light and flash light during the set exposure time 2 _QVfa
(QVfa is data obtained by logarithmically compressing the total light amount) and the value corresponds to the ratio of the light amount of only the stationary light (2 _BVa-TVs) . This is due to the following reason: 2 _QVf + 2 _BVa-TVs = 2 _QVfa ...(1) Dividing both sides of equation (1) by 2 _BVa-TVs , 2 _{QVf-(BVa-TVs)} +1=2〓+1=2 _QVfa /2 _BVa-TVs …(2
), and by taking the logarithm of both sides, we obtain the relationship QVfa−(BVa−TVs)=log ₂ (1+2〓)…(3). Therefore, log ₂ (1+2〓) is a value corresponding to the ratio of the total light amount to the light amount due only to the stationary light. Data from this ROM 44 is output to a decoder 58 and an adder circuit 45.

The addition circuit 45 inputs the data from the ROM 44, the data from the film sensitivity setting device 22, and the data from the subtraction circuit 42, and calculates log ₂ (1+2〓).
Perform the calculation +(BVa-TVs)+SV=AVx. This calculation result corresponds to an appropriate aperture value for the total amount of light during flash photography. The reason why this data corresponds to the appropriate aperture value is that QVfa + SV = AVx
holds, and on the other hand, from equation (3), QVfa=BVa−TVs+
This is because log ₂ (1+2〓) holds true, so AVx=BVa−TVs+SV+log ₂ (1+2〓) …(4). Data from this adder circuit 45 is output to a decoder 54.

The ROM 46, like the ROM 44, has a subtraction circuit 4.
The address is specified by the data Δ from 3. Data log ₂ (1+2 _- 〓) corresponding to the designated data Δ has previously been fixedly stored at the address designated by the data Δ, and this data is sent to the display device 6 via the decoder 59. This data log ₂ (1
+2 _- 〓) is a value corresponding to the ratio of the total light amount to the flash light amount during flash photography. This is due to the following reasons. That is, by dividing both sides of equation (1) by 2 _QVf , we obtain the following relationship: 1+2 _{(BVa-TVs)-QVf} = 1+2 _- 〓=2 _QVfa /2 _QVf ...(5), and both sides of equation (5) This is because by taking the logarithm of , the following relationship is obtained: QVfa−QVf=log ₂ (1+2 _- 〓)...(6).

In addition, timing controller 8, register 3
0, 32, arithmetic circuit 4, display decoder 50-5
Needless to say, 9 can be replaced with one microcomputer.

Furthermore, it is also possible to use an integral type photometry circuit for photometry of stationary light. In addition, the flash light emitting device 7
Although the light emission signal of is shown in the drawing as a simplified version,
It is well known to use a semiconductor switching device that is turned on by a falling signal at terminal 804 or a mechanical switch (eg, a relay switch) that is closed by a falling signal.

Further, although the inside of the arithmetic circuit 4 is only shown in a very simplified manner, it can be easily realized by a person skilled in the art by using, for example, a microcomputer.

Effects As detailed above, by using the photometric device to which this invention is applied, it becomes possible to automatically obtain various data in flash photography that could not be obtained automatically in a short time and with a single operation. Furthermore, even when the amount of light emitted by the flashlight emitting device is switched from the amount used when the flash was actually emitted to a different amount, various data based on the value at the time of switching can be obtained without having to emit the light again. Furthermore, it is possible to obtain various data when the set exposure time, film sensitivity, etc. are changed, and various data when the brightness of the stationary light changes, without causing the flash light emitting device to emit light again. I can do it.

[Brief explanation of the drawing]

FIG. 1 is an overall circuit diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing a specific example of the timing controller 8 shown in FIG. 1, and FIG. 3 is a circuit diagram of the logic circuit LU ₀ shown in FIG. 4 is a circuit diagram of the logic circuit LU ₂ shown in FIG. 2, FIG. 5 is a timing chart of the timing controller 8, and FIG. 6 is a block diagram showing a specific example of the arithmetic circuit 4. PD: Photodetector, C ₀ , C ₂ ; Capacitor, R ₀ ,
R ₂ ; Resistance, D ₀ , D ₂ , D ₄ ; Diode, OA ₂ ,
OA ₄ ; operational amplifier; 1; A-D converter; 20; exposure time setting device; 22; film sensitivity setting device;
24; change value setting device; 7; arithmetic circuit; 6; display device; 7; flashlight emitting device; 8; timing controller; S ₀ ; photometry start switch.

Claims (1)

[Scope of Claims] 1. By removing and integrating the steady light component in the photometric output for a predetermined integration time that includes the light emission time of the flashlight emitting device that emits light in advance, the light emission of the flashlight emitting device during the above integration time is calculated. a first circuit that obtains a first signal that is the amount of received flash light related to the amount of light received; and a second circuit that obtains a second signal that corresponds to the brightness of only the steady light when the flash light emitting device is not emitting light. Based on the circuit No. 2, an exposure time setting device, a film sensitivity setting device, the first and second signals, a signal from the exposure time setting device, and a signal from the film sensitivity setting device, 1. A photometric device for flash photography, comprising: an arithmetic circuit that calculates data corresponding to an appropriate aperture value during flash photography. 2 further comprising a change value setting device for setting a change value for the amount of light emitted by the flashlight emitting device, and the arithmetic circuit changing the first signal by a value corresponding to the signal from the change value setting device; A photometric device for flash photography according to claim 1, characterized in that it has the following. 3. A photometric device for flash photography according to claim 1 or 2, further comprising a display device that displays the data calculated by the arithmetic circuit. 4. Any one of claims 1 to 3, characterized in that the arithmetic circuit includes a timing control circuit that outputs a signal for taking in a new signal and performing an operation at fixed time intervals. A photometric device for flash photography described in . 5. A photometering circuit that outputs a voltage proportional to the output current of the light receiving element during the light emitting operation of the flashlight emitting device that emits light in advance, and only the alternating current component generated by the light emission of the flashlight emitting device from the output voltage of this photometering circuit. A high-pass filter connected to the output of the photometric circuit that outputs , a voltage-current conversion circuit that converts the output voltage of the high-pass filter into a current, and an integration circuit that integrates the output current of the voltage-current conversion circuit. In addition, a first circuit for obtaining a first signal that is the amount of flash light received corresponding only to the light emission of the flashlight emitting device, and a brightness of only the steady light when the flashlight emitting device is not emitting light. a second circuit for obtaining a second signal, an exposure time setting device, a change value setting device for setting a change value of the amount of light emitted by the flashlight emitting device;
and the signal from the exposure time setting device, calculate data corresponding to the ratio of the amount of light received only from the steady light and the amount of flash light received only from the amount of light emitted by the flashlight emitting device during the set exposure time. A photometric device for flash photography, characterized by comprising a calculation circuit. 6. The photometric device for flash photography according to claim 5, further comprising a display device that displays the data calculated by the arithmetic circuit. 7. The method according to claim 5 or 6, further comprising a timing control circuit that outputs a signal for the arithmetic operation circuit to take in a new signal and perform an operation at fixed time intervals. Photometering device for flash photography. 8 A photometering circuit that outputs a voltage proportional to the output current of the light receiving element during the light emitting operation of the flashlight emitting device that emits light in advance, and only the alternating current component generated by the light emission of the flashlight emitting device from the output voltage of this photometering circuit. A high-pass filter connected to the output of the photometric circuit that outputs , a voltage-current conversion circuit that converts the output voltage of the high-pass filter into a current, and an integration circuit that integrates the output current of the voltage-current conversion circuit. In addition, a first circuit for obtaining a first signal that is the amount of flash light received corresponding only to the light emission of the flashlight emitting device, and a brightness of only the steady light when the flashlight emitting device is not emitting light. The second
a second circuit for obtaining a signal; an exposure time setting device;
The ratio of the amount of light due to only the constant light and the amount of light due to both the flash light emitting device and the constant light during the exposure time set based on the first and second signals and the signal from the exposure time setting device. A photometric device for flash photography, characterized in that it is equipped with an arithmetic circuit that calculates data corresponding to. 9. A photometric device for flash photography according to claim 8, further comprising a display device that displays the data calculated by the arithmetic circuit. 10. The invention according to claim 8 or 9, further comprising a timing control circuit that outputs a signal for the arithmetic circuit to take in a new signal and perform an operation at fixed time intervals. Photometer for flash photography. 11 A photometering circuit that outputs a voltage proportional to the output current of the light receiving element during the light emitting operation of the flashlight emitting device that emits light in advance, and only the alternating current component generated by the light emission of the flashlight emitting device from the output voltage of this photometry circuit. A high-pass filter connected to the output of the flash circuit that outputs a voltage, a voltage-current conversion circuit that converts the output voltage of the high-pass filter into a current, and an integration circuit that integrates the output current of the voltage-current conversion circuit. In addition, a first circuit for obtaining a first signal that is the amount of flash light received corresponding only to the light emission of the flashlight emitting device, and a brightness of only the steady light when the flashlight emitting device is not emitting light. a second circuit for obtaining a second signal, an exposure time setting device, and a second circuit for controlling both the flash light emitting device and the constant light based on the first and second signals and the signal from the exposure time setting device; 1. A photometric device for flash photography, comprising: an arithmetic circuit that calculates data corresponding to a ratio between the amount of light emitted by the flash light emitting device and the amount of flash light emitted only by the flash light emitting device. 12 Further comprising a change value setting device for setting a change value for the amount of light emitted by the flashlight emitting device, and the arithmetic circuit changing the first signal by a value corresponding to the signal from the change value setting device. A photometric device for flash photography according to claim 11, characterized in that it has the following. 13. A photometric device for flash photography according to claim 11 or 12, characterized by comprising a display device that displays the value calculated by the arithmetic circuit. 14. Any one of claims 11 to 13, characterized in that the arithmetic circuit includes a timing control circuit that outputs a signal for taking in a new signal and performing an operation at fixed time intervals. A photometric device for flash photography described in .