JPH037086B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera capable of flash photography using a speedlight.

Conventionally, with this type of camera, when there is a significant difference in brightness between the main subject and the background due to extreme backlighting, the main subject is exposed during daytime flash photography, in which the speedlight's light is used to properly expose the main subject. It was necessary to correct the amount of light emitted by the speedlight by taking into account the normal light coming from the camera. For this purpose, it is necessary to perform the above correction by operating exposure factor setting means such as film sensitivity and aperture value provided in a speedlight or camera. This is troublesome for the photographer, and is something that is often forgotten. This led to failures in filming.

SUMMARY OF THE INVENTION An object of the present invention is to provide a correction device for daytime flash photography that eliminates the above-mentioned drawbacks by automatically correcting the light emission amount of a speedlight taking normal light into account when daytime flash photography is selected. It is in.

Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a schematic diagram showing a photometric optical system. Subject light passing through a photographing lens 1 and an aperture 2 is reflected by a mirror 3 and formed into an image on a focus plate 4. FIG. This object image is observed through a condenser lens 5, a pentagonal roof prism 6, and an eyepiece lens 7. Also,
The object image on the focus plate 4 is formed on the light receiving surface of the photoelectric element PD by a prism 8 attached to the roof surface of the penta roof prism 6 and a relay lens 9. This photoelectric element PD has a light-receiving surface pattern as shown in FIG. That is, on the substrate B, there are a photoelectric element PD ₀ that measures the center area of the screen, photoelectric elements PD ₁ and PD ₂ that measure the upper left and lower areas of the screen, and photoelectric elements PD ₄ and PD that measure the upper right and lower area of the screen. ₃ are formed respectively.

PD100 is a light receiving element for TTL light control, which receives the light from the subject reflected on the film surface after mirror up.

FIG. 3 is a diagram showing an apparatus according to an embodiment of the present invention. This device is configured to give priority to shutter speed.

This device includes a photometry circuit 100, a multi-photometry calculation circuit 200, an apex calculation circuit 300, a display control section 400, an exposure control section 500, a speedlight control section 600, and a speedlight signal, open aperture information Av ₀ , shutter speed Tv, film Sensitivity Sv
a camera including an information setting section 700 for various information such as;
It consists of a speedlight 800 attached to the camera. This speedlight 800 is generally removable, and can be put out of use by detaching it from the camera or turning off the power switch _Sw1 .

The photometry circuit 100 includes a plurality of light receiving elements shown in the second figure, divides the field into a plurality of regions, measures the light, and outputs photoelectric outputs P ₀ to P ₄ corresponding to the brightness of each region.
The information setting section 7 outputs the photoelectric outputs _P0 to _P4 .
Av ₀ is added to the open aperture information starting from 00 to generate each luminance information P ₂₀₀ to P ₂₀₄ .

The multi-photometry calculation circuit 200 includes the photometry circuit 100
The luminance information P ₂₀₀ to _{P 204} is inputted from the input device, processed, and processed according to the relative relationship of each piece of information P ₂₀₀ to _{P 204} and the speedlight signal from the information setting section 700 to suit each shooting condition. Brightness information
Extract Bv and output.

The apex calculation circuit 300 inputs processed brightness information Bv from the multi-photometry calculation circuit 200, inputs various information Av ₀ , Tv, Sv, and speedlight signal from the information setting section 700, and performs apex calculation.
The display control section 400 and the exposure control section 500 are driven.

When the speedlight starts flashing after the mirror 3 shown in FIG.
The PD 100 measures light, and when the amount of light emitted reaches a predetermined value, a light emission stop signal is sent to the speedlight 800 to stop the flash light emission.

Next, the configuration of the apparatus shown in the first diagram will be explained in detail.

The dedicated speedlight 800 for TTL metering camera has a power switch Sw ₁ and a step-up power supply circuit 1.
1, a trigger circuit 12, a flash discharge tube 13, and a thyristor circuit 14. The boost power supply circuit 11 is
When the speedlight is not used, the L ₀ output is transmitted to the information setting section 700 on the camera side, but when the speedlight is used and the power switch Sw ₁ is turned on, the Hi output is transmitted to the information setting section 700 on the camera side.
Then, charging of a main discharge capacitor (not shown) is started for flash light emission. After charging is completed, when the X contact switch Sw ₂ on the camera side is turned on, the trigger circuit 12 causes the flash discharge tube 13 to start emitting flash light. When the amount of light emitted reaches a predetermined amount,
The thyristor circuit 14 stops the flashlight emission of the flash discharge tube 13 in response to a light emission stop signal from the speedlight control circuit 600 on the camera side.

The information setting section 700 inverts the output of the boost power supply circuit 11 using an inverter _INV1 to generate a speedwrite signal. When not using speedlight,
In other words, when the speedlight is not attached to the camera, or even when the speedlight is attached but the power switch _Sw1 is OFF, the output of the boost power supply circuit 11 is Lo.
The speedlight signal inverted by inverter INV ₁ is Hi. When using a speedlight, that is, attach the speedlight to the camera and turn switch Sw ₁ .
When turned on, the circuit 11 becomes a Hi output, so the speedlight signal becomes Lo. Furthermore, the information setting section 700 generates outputs representing various information set at that time, namely, film sensitivity information Sv in the apex display, shutter speed information Tv, and open aperture information _Av0 .

The photometric circuit 100 includes a plurality of photoelectric elements _PD0 to _PD4 shown in FIG. This photoelectric element PD ₀ ~ _{PD 4}
divides the field into multiple constituent areas and measures the light.
Mutually independent photometric information corresponding to each component area
Generate P ₀ to P ₄ . The photometric circuit 100 further inputs the open aperture information Av ₀ from the information setting section 700 and outputs the result of adding this to the photometric information P ₀ to _{P 4} , P ₂₀₀ = P ₀ + Av ₀ P ₂₀₁ = P ₁ + Av ₀ P ₂₀₂ =P ₂ +Av ₀ P ₂₀₃ =P ₃ +Av ₀ } (1) Generates P ₂₀₄ =P ₄ +Av ₀ . These outputs P ₂₀₀ to _{P 204} become brightness information Bv of each area.

Next, the configuration of the multi-photometry calculation circuit 200 will be explained. The maximum value detection circuit 21 is the photometry circuit 10
Input the output P ₂₀₀ to _{P 204} of 0, and select the maximum value from among them.
Detect Pmax and output it. The average value calculation circuit 22 inputs the outputs P ₂₀₀ to _{P 204} of the photometric circuit 100 and calculates the average value of these, for example, the average value Pmean=1/5 (P ₂₀₀ +P ₂₀₁ +P ₂₀₂ +P ₂₀₃ +
P ₂₀₄ ) (2) is output. The minimum value detection circuit 23 is the photometry circuit 10
Input the output P ₂₀₀ to _{P 204} of 0, and select the minimum value from among them.
Detect Pmin and print it. Arithmetic circuit 24
are the maximum value Pmax and the average value from circuits 21 and 22
Pmean and the first photometric output PH (Bv),
That is, PH=k ₁ Pmax+(1−k ₁ )Pmean (3) is output. Output of average value calculation circuit 22
Pmean is used as is as the second photometric output.
The arithmetic circuit 25 calculates the average value from the circuits 22 and 23.
Pmean and the minimum value Pmin are input, and the third photometric output PL, that is, PL=k ₂ Pmin+(1−k ₂ )Pmean (4) is output. The luminance difference calculation circuit 26 inputs the output Pmax of the circuit 21 and the output Pmin of the circuit 23,
Outputs the difference between both outputs, that is, the luminance difference ΔP=Pmax−Pmin (5).

Since this brightness difference ΔP is an apex representation of brightness, that is, a subtraction of the logarithm value of brightness, it can be said to be the ratio between the maximum brightness and the minimum brightness. The comparison circuit 27 compares the output ΔP of the circuit 26 due to the luminance difference with a reference value α. The comparison circuit 27 generates a Lo output when the brightness difference ΔP is large, that is, ΔP≧α (6), and generates a Hi output when the brightness difference is small, that is, ΔP<α (7). . The comparison circuit 28 compares the output Pmax of the circuit 21 with the reference value Pth, and determines whether to use the daytime flash photography mode (the photography mode used when the subject is dark and the background is bright due to backlighting) if a speedlight is to be used. It is detected whether it is necessary to use the general flash photography mode (a photography mode performed when the entire subject is dark). Furthermore, this output
Pmax is most affected by the light source of the object, so it is suitable for use in the above-mentioned detection. Of course, the output Pmean may also be used. Also the standard value
Pth is set to a value of EV8 to EV10 (ASA100), for example. When Pmax≧Pth (8), the comparator circuit 28 generates a Hi output.
In this case, the field is bright, and it is therefore detected that if a speedlight is used, it will be in daytime flash photography mode. In this case, the amount of flash light emission must be controlled in consideration of the influence of light other than the flash discharge tube, ie, normal light. Next, when Pmax<Pth (9), the comparison circuit 28 generates a Lo output.
In this case, the subject is dark, and if a speedlight is used, it is detected that the general flash photography mode will be used. In this case, there is no need to consider the influence of normal light, etc., as described above. Next, the photometric luminance information P ₂₀₀ to _{P 204} is input to each non-inverting input terminal of the comparators C 0 to C ₄ , and _the output of the circuit 22 is input to all the inverting input terminals of the comparators C ₀ to C ₄ . Pmean is input. Comparators C ₀ to _{C 4} output Hi when P ₂₀₀ to P ₂₀₄ are higher than Pmean, respectively.
Otherwise, it generates a Lo output and generates relative brightness information between each constituent area of the object scene. AND circuit AND ₁ , inverter INV ₂ , NOR circuit NOR ₁ ~
NOR ₄ , OR circuit OR ₁ , inverter INV ₃ , AND
A logic circuit group composed of the circuits AND ₂ and AND ₃ and the OR circuit OR ₂ receives the luminance difference information for each constituent region from the comparators C ₀ to C ₄ and the comparison circuit 27
The brightness difference information from the information setting section 700 and the speedlight signal from the information setting section 700 are input, and the gate circuits 29, 30, 31 are driven according to these information, and the circuit 24
output PH of circuit 22, output Pmean of circuit 22, and circuit 25
Outputs PL suitable for the photographing conditions at that time are selected from among the outputs PL, and extracted as the output of the multi-photometry calculation circuit 200.

Each case will be explained below.

[A] When the speedlight is not used, the Hi-level speedlight signal from the information setting section 700 is inverted to Lo by the inverter INV ₃ , and
Since it is applied to the AND circuit AND ₂ , the AND circuit
The output of AND ₂ is independent of the output of comparison circuit 27.
Become Lo. On the other hand, the Hi-level speedlight signal is directly applied to the AND circuit _AND3 .
Therefore, the outputs of the AND circuit AND ₃ and the OR circuit OR ₂ are the same as the output of the OR circuit OR ₁ . Also, Hi
Level speedlight signal is AND circuit AND ₁
has been entered.

(1) When a speedlight is not used and the central area PD ₀ and lower half areas PD ₂ and PD ₃ of the light receiving element are bright, that is, when P ₂₀₀ ≧Pmean P ₂₀₂ ≧Pmean (10) P ₂₀₃ ≧Pmean holds. , it is determined that the main subject is in the bright area, and the output that matches the brightness of the main subject is PH.
Therefore, this PH is extracted as the output of the multi-photometry calculation circuit 200.

The operation of the multi-photometry calculation circuit 200 in this case will be explained.

Since the photodetectors PD ₀ , PD ₂ , and PD ₃ are in the bright area,
Comparators C ₀ , C ₂ , C ₃ connect Hi output to AND circuit AND ₁
to be applied. Furthermore, since the speedlight signal input to the AND circuit AND ₁ is also Hi, the AND circuit AND ₁ applies a Hi output to the gate circuit 29 . At this time, the gate circuit 29 allows the output PH of the arithmetic circuit 24 to pass through. Also, at this time, comparator C ₀
is a Hi output, so inverter INV ₁ becomes a Lo output. Since comparators C ₂ and C ₃ are Hi output, NOR circuit
NOR ₁ to NOR ₃ are Lo outputs. Therefore, since all the inputs of the OR circuit _OR1 are set to Lo, the output is also set to Lo. Furthermore, when a speedlight is not used, the output of the OR circuit OR ₁ and the output of the OR circuit OR ₂ are equal as described above, so the OR circuit
The output of OR ₂ also becomes Lo. Also, AND circuit
Since AND ₁ is Hi output, NOR circuit NOR ₄ is Lo
becomes the output. This gate circuit 30 inputs the Lo output of the NOR circuit NOR ₄ and the OR circuit OR ₂ ,
31 are the outputs Pmean and Pmin of the circuits 24 and 25
cut off. Therefore, only the output PH of the circuit 24 is extracted by the gate circuit 29 as the output of the multi-photometry calculation circuit 200.

(2) Next, when no speedlight is used and (a) when the central region PD ₀ is dark, that is, when P ₂₀₀ ≦Pmean (11) holds, (b) when the left half regions PD ₁ and PD ₂ are When it is dark, that is, when P ₂₀₁ ≦Pmean and P ₂₀₂ ≦Pmean (12) holds; (c) When the lower half regions PD ₂ and PD ₃ are dark, that is, when P ₂₀₂ ≦Pmean and P ₂₀₃ ≦Pmean (13) or (d) when the right half areas PD ₃ and PD ₄ are dark, that is, when P ₂₀₃ ≦Pmean and P ₂₀₄ ＜Pmean (14) hold, in (a) the main subject is The central area of the screen where there is a high probability that
PD ₀ is dark. In the case of (c), it can be determined that the subject is backlit, and the brightness of the main subject is close to the brightness of the dark areas PD ₂ and PD ₃ at the bottom of the screen. (b),
In case (d), hold the camera vertically and measure the light.
It can be determined that P ₁ , P ₂ or P ₃ , P ₄ is the brightness information of the lower area and it is backlit, and the brightness of the main subject is the brightness of the screen that is the dark area at this time. Lower part PD ₁ , PD ₂ or PD ₃ ,
Close to the brightness of PD ₄ .

As mentioned above, in cases (a) to (d), the main subject is in the dark area, so the output that matches the brightness of the main subject at this time is PL, and this PL is the output of the multi-photometry calculation circuit 200. Extract as.

Next, the multi-photometry calculation circuit 20 in cases (a) to (d)
The operation of 0 will be explained.

At the time of (a), that is, when the area PD ₀ of the light receiving element is dark, the comparator C ₀ generates a Lo output. Therefore,
The outputs of the inverter INV ₂ and the OR circuit OR ₁ become Hi. Also, from the above, when the speedlight is not used as in this case, the output of the OR circuit OR ₁ and
Since the output of the OR circuit OR ₂ becomes equal, the output of the OR circuit OR ₂ also becomes Hi. The gate circuit 31 which receives the Hi output of the OR circuit _OR2 passes the output PL of the circuit 25. Also, at this time, the OR circuit
Since OR ₂ is a Hi output, the NOR circuit NOR ₄ is a Lo output. Since comparator C ₀ is Lo output, AND circuit
AND ₁ becomes Lo output. Therefore, AND circuit
The gate circuits 29 and 30 to which the Lo outputs of AND ₁ and NOR circuit NOR ₄ are respectively input are connected to the circuit 24,
22 outputs PH and Pmean are cut off. Therefore,
Only the output PL of the circuit 25 is extracted as the output of the multi-photometry calculation circuit 200.

At the time of (b), since the regions PD ₁ and PD ₂ of the light receiving elements are dark, the comparators C ₁ and C ₂ generate Lo outputs, and the NOR circuit NOR ₁ becomes a Hi output.

At the time of (c), since the regions PD ₂ and PD ₃ of the light receiving elements are dark, the comparators C ₂ and C ₃ generate Lo outputs, and the NOR circuit NOR ₂ becomes a Hi output.

At the time of (d), since the regions PD ₃ and PD ₄ of the light receiving element are dark, the comparators C ₃ and C ₄ generate Lo outputs, and the NOR circuit NOR ₃ becomes a Hi output.

In any of the above cases (b) to (d), the NOR circuit
OR circuit inputting Hi output of NOR ₁ to NOR ₃
OR ₁ generates a Hi output. Also, from the above, when not using a speedlight as in this case,
Since the outputs of OR circuits OR ₁ and OR ₂ are equal,
The output of OR circuit OR ₂ also becomes Hi. This OR circuit
The gate circuit 31 which inputs the Hi output of OR ₂ ,
The output PL of the circuit 25 is passed through. In addition, in this case, the NOR circuit NOR ₄ , which has input the Hi output of the OR circuit OR ₂ , applies the Lo output to the gate circuit 30,
Gate circuit 30 cuts off the output Pmean of circuit 22. Moreover, in the case of (b) to (d), the comparator C ₂ ,
Since one or both of _C3 generates a Lo output and applies that Lo output to the AND circuit AND 1, the AND circuit _{AND 1 always} becomes a Lo output, and the gate circuit 29 that inputs this Lo output
cuts off the output PH of the circuit 24. Therefore, only the output PL of the circuit 25 is output from the multi-photometry calculation circuit 2.
Extracted as an output of 00.

(3) No speedlight is used, and (1) and (2) above.
When none of the cases apply, the AND circuit
The outputs of AND ₁ and OR circuit OR ₂ both become Lo,
The output of the NOR circuit NOR ₄ becomes Hi, and the NOR
Gate circuit 30 inputting Hi output of circuit NOR ₄
passes the output Pmean of circuit 22. Also
The circuits 29 and 30 that input the Lo outputs of the AND circuit AND ₁ and the OR circuit OR ₂ are the outputs of the circuits 24 and 25.
Blocks PH and PL. Therefore, only the output Pmean is extracted as the output of the multi-photometry calculation circuit 200.

[B] When using a speedlight In this case, the power switch _Sw1 of the speedlight 800 is turned on, and the boost power supply circuit 11 generates a Hi output. The Hi output of this circuit 11 is inverted to Lo by the inverter INV ₁ of the information setting section 700, and the information setting section 700 outputs a Lo level speedlight signal. This Lo level speedlight signal is input to the AND circuit AND ₃ , so
The AND circuit AND ₃ becomes a Lo output regardless of the output of the OR circuit OR ₁ , and cuts off the output signal of the OR circuit OR ₁ . Further, the low level speedlight signal is inverted to high level by the inverter _INV3 , and the high level output is input to the AND circuit _AND2 . Therefore,
The output signal of the AND circuit AND ₂ and the output signal of the OR circuit OR ₂ are the same as the output signal of the comparison circuit 27. In addition, the Lo level speedlight signal is an AND circuit.
Since it is input to AND ₁ , the output of AND circuit AND ₁ is always independent of the output signals of comparators _C0 to _C4 .
It becomes Lo output.

(1) When a speedlight is used and the brightness difference ΔP of the subject is smaller than α, that is, when equation (7) holds true, there is a possibility of extreme backlighting. In other words, when daytime flash photography is selected, if there is an extremely high-brightness area in each photometric division area, such as direct light from a light source, the low-brightness area in the same area will be buried, and the photometry information will be lost. It will no longer be expressed as such. Therefore, at this time, it is preferable to adjust the exposure to the low brightness area rather than to adjust the exposure to the high brightness area. Therefore, at this time, the photometric output PL is extracted as the output of the multi-photometric calculation circuit 200.

That is, when equation (7) holds true, the output of the comparison circuit 27 becomes Hi. Also, from the above, when using a speedlight, the output signal of the OR circuit OR ₂ is the same as the output signal of the comparison circuit 27, so the OR
Circuit OR ₂ produces a Hi output. This OR circuit
The gate circuit 31 which inputs the Hi output of OR ₂ ,
The output PL of the circuit 25 is passed through. Also OR circuit
Since the Hi output of OR ₂ is applied to the NOR circuit NOR ₄ , the output of the NOR circuit NOR ₄ becomes Lo. Furthermore, from the above, when using a speedlight, AND
The circuit AND ₁ is a Lo output. Therefore,
Lo of this AND circuit AND ₁ and NOR circuit NOR ₄
The gate circuits 29 and 30 inputting the outputs cut off the outputs PH and Pmean of the circuits 24 and 22. Therefore, only the output PL that has passed through the gate circuit 31 is extracted as the output of the multi-photometry calculation circuit 200.

(2) When a speedlight is used and the field brightness difference ΔP is large, that is, when equation (6) holds, there is a strong possibility that the main subject is in a dark area when daytime flash photography is selected. . Therefore, it is preferable to properly expose the main subject using the light of a speedlight, and to give an average exposure to the background, which has high brightness, to avoid overexposure. Therefore, at this time, the photometric output Pmean is extracted as the output of the multi-photometric calculation circuit 200.

That is, when equation (6) holds true, the output of the comparator circuit 27 becomes Lo, and the AND circuit AND ₂ also becomes a Lo output. Furthermore, since the AND circuit AND ₃ also outputs Lo due to the Lo level speedlight signal, the output of the OR circuit OR ₂ also becomes Lo. Also,
The output of the AND circuit AND ₁ also becomes Lo due to the Lo level speedlight signal. Therefore,
The output of the NOR circuit NOR ₄ becomes Hi, and the gate circuit 30 passes the output Pmean of the circuit 12.
Also, the output of AND circuit AND ₁ and OR circuit OR ₂ is
Since it is set to Lo, the gate circuits 29 and 31 cut off the outputs PH and PL of the circuits 24 and 25. In this way, only the output Pmean of the circuit 22 is extracted as the output of the multi-photometry calculation circuit 200.

Next, the apex calculation section 300 will be explained.

The apex calculation circuit 300 receives luminance information (PH, Pmean, or
PL), film sensitivity information Sv of the information setting section 700,
Shutter speed information Tv, aperture information Av ₀ , and speedlight signals are input to perform apex calculation according to the set shooting mode, and based on the calculation results, display control section 400 and exposure control section 5
Drive 00.

The shutter speed limiting circuit 34 is connected to the information setting section 70.
The shutter speed information Tv from 0 and the speedlight signal and the output signal of the comparison circuit 28 are input.
When the speedlight is not used, that is, when the speedlight signal is Hi, the shutter speed limiting circuit 34 directly transmits the shutter speed information Tv from the information setting section 700 to the arithmetic circuit 35 without any restriction. When using a speedlight,
The shutter speed limiting circuit 34 applies the following restrictions to the shutter speed information Tv from the information setting section 700. That is, using a speedlight and
When formula (9) Pmax<Pth holds true, that is, in the general flash photography mode, the comparator circuit 28 transmits a Lo output to the shutter speed limiting circuit 34. At this time, the shutter speed limiting circuit 34 fixes the shutter speed information Tv to the speedlight tunable shutter speed Tvx and transmits it to the arithmetic circuit 35. This is because there is no need to reduce the shutter speed to a speed lower than the speedlight tunable shutter speed Tvx in the general flash photography mode.
Next, when a speedlight is used and formula (8) Pmax≧Pth holds true, that is, during daytime flash photography mode, the comparator circuit 28 transmits a Hi output to the shutter speed limiting circuit 34. At this time, the shutter speed limiting circuit 34 limits the shutter speed Tv to a speedlight tunable shutter speed Tvx or less and transmits the result to the arithmetic circuit 35.

The calculation circuit 35 receives shutter speed information Tv from the shutter speed limiting circuit 34, film sensitivity information Sv from the information setting section 700, and brightness information Bv (PH, Pmean or
PL), performs apex calculation Bv+Sv-Tv=Av (15), and outputs control aperture information Av. The display control unit 400 displays the aperture according to this control aperture value information Av. The arithmetic circuit 36 inputs the control aperture information Av from the arithmetic circuit 35 and the open aperture information Av ₀ from the information setting section 700, and calculates (Av)-( _Av0 )=(Av- _Av0 )( 16), the number of aperture steps (Av-Av ₀ ) is transmitted to the exposure control circuit 500, and the exposure control circuit 500 performs an aperture operation equal to the number of steps after the shutter release (Av-Av ₀ ). The NOR circuit NOR ₅ connects the speedlight signal from the information setting section 700 to the comparison circuit 28.
The output of and the input. Then, during general flash photography, the speedlight signal becomes Lo, and
Since Pmax<Pth holds true, the output of the comparison circuit 28 also becomes Lo. Therefore, the NOR circuit NOR ₅ applies Hi output to the display control section 400 and the exposure control section 500. At this time, the display control section 400, the exposure control section 50
0 displays the speedlight synchronized shutter speed Tvx and controls exposure regardless of the output of the arithmetic circuit 35. In other cases, that is, in normal shooting mode and daytime flash shooting mode, NOR
The circuit NOR ₅ generates a Lo output and the display control section 40
0, and the exposure control section 500 operates according to the output of the arithmetic circuit 35.

Next, regarding the speedlight control section 600, the photometric head amplifier A is connected to the TTL light receiving element PD1.
00 (see first illustration). In Figure 1, after the mirror 3 is raised during photography, the lens 1
The light incident on the film surface and reflected by the film surface is photometered by the photodetector PD100, and the head amplifier A applies the photometry output to the speedlight control circuit 38. The film sensitivity correction circuit 37 is connected to the comparison circuit 28.
and the film sensitivity information Sv from the information setting section 700 are input. Then, in the general flash photography mode, when Pmax<Pth holds and the output of the comparison circuit 28 becomes Lo, the sensitivity correction circuit 37 directly transmits the film sensitivity information Sv to the speedlight control circuit 38. Therefore, at this time, the speedlight control circuit 38 sends a light emission stop signal to the thyristor circuit 14 when the amount of flash light emitted by the speedlight 800 reaches a predetermined value according to the film sensitivity information Sv and the photometric output of the photometric head amplifier A. is applied to stop the flash emission. On the other hand, in the daytime flash photography mode, Pmax≧Pth holds, and the output of the comparison circuit 28 becomes Hi. At this time, the film sensitivity correction circuit 37 performs the following correction on the film sensitivity information Sv.

(Sv) + (δ) = (Sv + δ) (17) δ in the above equation is a value considering normal light, for example 2/3
The value is about ~2 [EV]. A speedlight control circuit 38 inputting this corrected film sensitivity information (Sv+δ) generates a light emission stop signal earlier by an amount corresponding to δ than when film sensitivity correction is not performed, and stops the flash light emission of the speedlight 800.

In this example, when photographing a main subject that is backlit during the day using a flashlight, the speedlight's flash emission time is shortened by the amount of normal light δ from the main subject, so the main subject is photographed under normal light. Overexposure is prevented by that amount.

Furthermore, by increasing the correction amount δ, it is possible to further suppress the amount of light emitted from the speedlight, thereby making the main subject slightly underexposed. This will automatically allow you to take pictures that give off the right amount of backlit atmosphere.

Here, the operation sequence in the daytime flash photography mode will be explained in detail. speedlight 8
Attach 00 to the camera body. Next, turn on the speedlight power switch Sw ₁ . The boost power supply circuit 11 starts charging the main capacitor. When the charging voltage reaches the voltage that enables the flash discharge tube to emit a flash, the booster circuit 11 applies a Hi-level voltage to the information setting section 700, and the information setting section 700
A low level speedlight signal is generated by inverting the high level voltage to low using inverter INV ₁ .

Next, for example, when the release button is pressed halfway, the photometry start switch is turned on, and the photometry circuit 100 starts photometry. Then, the multi-photometry calculation section 200
Then, when the field brightness difference is small, that is, ΔP=
When Pmax−Pmin<α, the luminance difference calculation circuit 26,
Comparison circuit 27, comparators _C0 to _C4 , and logic circuit groups ( _AND1 , _INV2 , _NOR1 to _NOR4 , _OR1 , _INV3 ,
AND ₂ , AND ₃ , OR ₂ ), the third photometric output PL is extracted, and this is combined with various information in the information setting section 700, that is, film sensitivity information Sv, shutter speed information Tv, and open aperture information Av ₀ . input to the apex calculation circuit 300, apex calculation is performed,
The apex calculation circuit 300 generates control aperture information Av.

Next, when you press the shutter button completely,
Release the shutter and start shooting.

When the mirror 3 shown in the first figure is raised, the light transmitted through the photographic lens 1 no longer enters the photoelectric element PD, so the photometric luminance information Bv is stored immediately before the mirror is raised. Based on the stored value, the calculation circuit 3
5 performs the above calculation to calculate the control aperture value Av.
The display control section 400 displays the aperture value Av, and the exposure control section 500 controls the aperture operation of (Av- _Av0 ).

The leading shutter curtain starts running, and when it is completed, the speedlight control circuit 38 starts integrating the photometric output of the photometric head amplifier A. At the same time, the X contact switch _Sw2 is turned on, and the trigger circuit 12 causes the flash discharge tube 13 to start emitting flash light.

During the daytime flash photography mode, the sensitivity correction circuit 37
transmits the corrected sensitivity output (Sv+δ) to the speedlight control circuit 38, so this control circuit 38 sends the flash light emission stop signal to the thyristor circuit 14 earlier by δ than when no correction is performed, that is, during the general flash photography mode.
The flash discharge tube 13 stops emitting light.

Finally, the trailing curtain starts running and is complete.

The exposure control section 500 provides appropriate exposure to the background, and the speedlight control circuit 38 provides appropriate exposure to the main subject by flashing the speedlight whose light emission time is controlled.

In the above embodiment, the comparison circuit 28 compares the output Pmax of the maximum value detection circuit 21 with the reference value Pth, but the comparison circuit 28 compares the output Pmax of the maximum value detection circuit 21 with the reference value Pth.
Even if Pmean is compared with the reference value Pth′,
The same effects as in the above embodiment can be obtained. in this case,
The reference value Pth′ is a value lower than Pth and is EV7 to 8.
(ASA100) value.

Accordingly Pmean≧Pth′ When this is true, the camera is in daytime flash photography mode, Pmean＜Pth′ The general flash photography mode is when the following holds true.

FIG. 4 is a diagram showing a second embodiment of the present invention. The same parts as those in FIG. 3 are given the same reference numerals. The apparatus of this embodiment has an aperture-priority configuration.

Photometry circuit 100 and multi-photometry calculation circuit 200
has the same structure as that of the embodiment shown in FIG.

The information setting section 700' outputs film sensitivity information Sv, open aperture information Av ₀ , stop-down stage number information (Av-Av ₀ ), and a speedlight signal.

In the apex calculation circuit 300', the addition circuit 44 receives the aperture information from the information setting section 700'.
_Av0 and aperture stage number information (Av- _Av0 ) are input, and both are added to calculate and output set aperture value information Av. The arithmetic circuit 45 uses this set aperture information Av,
Brightness information Bv from the multi-photometry calculation circuit 200
(PH, Pmean or PL) and information setting section 700'
It inputs the film sensitivity information Sv from , performs the calculation Bv + Sv - Av = Tv (18), and outputs the control shutter speed information Tv.
The shutter speed limiting circuit 46 receives the shutter speed information Tv, the output of the comparison circuit 28, and the speedwrite signal from the information setting section 700'.
When the speedlight is not used, that is, when the speedlight signal is Hi, the control shutter speed information Tv
Display control unit 400 and exposure control unit 500 as they are
and the display control unit 400 and the exposure control unit 500
displays and controls the shutter speed according to the control shutter information Tv.

In general flash photography mode, the speedlight signal is
Lo, and the output of the comparison circuit 28 becomes Lo. At this time, the shutter speed limiting circuit 46 fixes the shutter speed to the speedlight synchronized shutter speed Tvx. On the other hand, in the daytime synchronized photography mode, the output of the comparison circuit 28 is inverted to Hi. At this time, the shutter speed limiting circuit 46 controls the shutter speed from Tvx to
Limit to Tvth range. Tvth is 1/15 to 1/30
It is a value of about seconds, and if it is less than Tvth,
This is because there is a risk of camera shake.

The calculation circuit 47 inputs the film sensitivity information Sv from the information setting section 700' and the setting aperture information Av from the addition circuit 44, and performs the calculation (Sv)-(Av)=(Sv-Av) (19). and outputs (Sv−Av). Correction circuit 4
8 inputs the output (Sv-Av) of the arithmetic circuit 47 and the output of the comparison circuit 28. Then, in the general flash photography mode, when the output of the comparator circuit 28 becomes Lo, the correction circuit 48 outputs the output of the arithmetic circuit 47 (Sv-
Av) is transmitted to the speedlight control circuit 49 as is without any correction. In the daytime flash photography mode, only when the output of the comparator circuit 28 becomes Hi, the correction circuit 48 performs the above correction of δ on the output (Sv-Av) of the arithmetic circuit 47, so that (Sv-Av)+δ=( Sv−Av+δ) (20) is transmitted to the speedlight control circuit 49.

Next, regarding the speedlight 800', the third
The speedlight 800 shown in the figure has a TTL dimming method that performs dimming by receiving reflected light from the film surface, but the speedlight 800' shown in FIG. It further includes a control circuit 49. The photometric head amplifier A is equipped with a flash light receiving element PD300 attached to a speedlight 800'.
Generates photometric output. Speedlight control circuit 4
9 inputs the photometric output of the head amplifier A and the output of the correction circuit 48. When the X contact turns on and the flash discharge tube 13 starts emitting flash light, the speedlight control circuit 49 starts integrating the photometric output of the head amplifier A, and when the amount of flash light emission reaches a predetermined amount,
The circuit 49 applies a light emission stop signal to the thyristor 14 to stop the discharge tube 13 from emitting flash light. During the daytime flash photography mode, the output given from the correction circuit 48 to the speedlight control circuit 49 is (Sv−Av+
δ), and in general flash photography mode (Sv−Av)
The light emission stop signal is generated earlier by δ than in the case where the flash light emission is stopped earlier.

Incidentally, in the above-described embodiment, a correction is made in which the amount of light emitted by a speedlight is reduced in order to prevent excessive exposure of the main subject due to normal light, but the present invention is not limited to this.

For example, in a so-called direct metering camera that automatically controls exposure by measuring the light reflected from the film surface (shutter curtain) in both normal shooting mode and general flash photography mode under daylight, the photometric output of the reflected light is Integration is started after the leading curtain starts traveling but before the leading curtain completes traveling. Therefore, the light emission amount of the speedlight is controlled to be smaller by the amount of the normal light metering output integrated from the time the integration of the metering output starts until the end of the front curtain travel (start of flash emission), so that the light emission amount of the speedlight is controlled to be lower than that of the main subject. There will be insufficient exposure. In such a case, make corrections to increase the amount of light emitted from the speedlight. For example, film sensitivity may be reduced by a predetermined amount.

Further, the comparator 28 that detects whether or not the daytime flash photography mode has been detected, and the correction circuit 37 that performs δ correction for the film sensitivity during the daytime flash photography mode are both located inside the speedlight 800 or within the camera body. It can also be placed in

The present invention can also be applied to a device that integrates a speedlight and a camera.

Detection of the daytime flash photography mode may be by detecting a selection switch or a manual operation such as wearing a speedlight or turning on a power switch, or by outputting from a known means for detecting the brightness difference between the main subject and the background. It may be something.

According to the present invention, in the case of daytime flash photography, the light emission amount of the speedlight is adjusted in consideration of the influence of normal light, so that the main subject is prevented from being overexposed or underexposed due to the influence of normal light. Ru.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a photometric optical system, FIG. 2 is a diagram showing an example of division of a photoelectric element, FIG. 3 is a diagram showing a first embodiment of the present invention, and FIG. 4 is a diagram showing the present invention. It is a figure which shows the 2nd Example of. Explanation of symbols of main parts, 13... flashlight emitting means, A, 38, A, 49... control means, 28,
NOR5...Detection means, 37, 48...Correction means.

Claims (1)

[Scope of Claims] 1. A flash photography device equipped with a control means for controlling the amount of light emitted by a flash light generating means so that the main subject is properly exposed in the field, which divides the field into a plurality of areas, divided photometry means for metering the field light that has passed through the photographic lens; and a photometry output of the divided photometry means corrected by the open aperture value of the photographic lens to obtain a photometry output corresponding to the insulation brightness of the photographic field. a photometric output correcting means for obtaining a photometric output, a photometry means for adjusting light that receives reflected light from the subject field caused by light emission from the flash generating means, a mode setting means for setting a flash photography mode, and a photometry output correcting means for setting a flash photography mode; a detection means for detecting that the daytime flash photography mode is selected by comparing the output level from the divided photometry means corrected by the photometry output correction means with a reference level during the flash photography mode; information setting means for outputting film sensitivity information set by the detection means; and information correction means for correcting the film sensitivity set by the information setting means in response to the output of the detection means; When the means detects that the daytime flash photography mode is not set, the amount of light emitted by the flash light generating means is controlled based on the film sensitivity information set by the information setting means and the photometry information of the light control metering means; Further, when the detection means detects that the flash photography mode is in the daytime, the amount of light emitted by the flash generation means is controlled based on the correction film sensitivity information of the information correction means and the photometry information of the light control metering means. A correction device for daytime flash photography. 2. The detection means compares the average output level or maximum output level regarding the corrected output of the plurality of photometry outputs of the divided photometry means with the reference level,
It outputs a high brightness signal to detect that the brightness of the subject exceeds a predetermined brightness to detect that it is in daytime flash photography mode, and when it detects that the brightness is lower than a predetermined brightness, it outputs a low brightness signal and outputs a general flash photography mode. 2. The correction device for daytime flash photography according to claim 1, wherein said correction device for daytime flash photography is capable of automatically selecting said daytime flash photography and said general flash photography by detecting the presence of said occurrence. 3. The flash photographing device includes a flash device and a photographing device to which the flash device can be attached and electrically connected when the flash device is attached; and the flash device includes the flash light generating means, the light metering means for adjusting light, and the control means, and the correction means of the photographing device controls the correction means of the flash device during the daytime flash photography mode. 2. A correction device for daytime flash photography according to claim 1, wherein said correction film sensitivity information is output to said control means.