JP2780350B2 - Camera system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera system, and more particularly, to a camera system having a bracket photographing function of photographing a predetermined number of images by switching the exposure amount of film one by one. It relates to a camera system.

2. Description of the Related Art In general, a camera shoots images with a predetermined exposure amount. However, in many cases, it is often difficult to determine the size of a photograph based on the determined exposure amount before taking the photograph. Therefore, bracket shooting is performed in which a plurality of pictures are taken of the same subject while changing the exposure amount for each picture. By the way, it is common practice not to use a flash for such bracket shooting, but if it is assumed that bracket shooting is performed under a flash of flash light, the flash emission of the conventional camera system is constant and the aperture By changing the value, the amount of exposure (exposure) of the flash to the film surface is changed.

Problems to be Solved by the Invention However, when the aperture value is changed in this way, the exposure of the background to which the flash light does not reach greatly changes as compared with that of the main subject, and the depth of field also changes. There is a problem that it is different from the one that has been done. If it is desired to change the film exposure amount of the main subject without changing the exposure of the background, the shutter speed may be changed when the aperture is changed. However, in order to change the shutter speed, it is necessary to make sure that it does not become faster than the tuning speed and that it does not become slower than the camera shake limit,
Control becomes difficult.

The present invention has been made in view of such a point,
It is an object of the present invention to provide a camera system capable of performing bracket photography favorably under flash light without the above-mentioned problem.

Means for Solving the Problems In order to achieve the above object, a camera system of the present invention includes a flash that performs flash light emission, a light emission amount switching unit that switches a flash light emission amount of the flash, an aperture and a shutter speed determination unit, Control means for switching the amount of light emission of the flash for each frame based on the determined aperture and shutter speed to perform photographing of a predetermined number of frames.

In this case, the light emission amount switching means may include a light control means for performing light control of the flash, and may be configured to switch the light control amount based on an output of the control means.

According to this configuration, the flash emission amount differs for each of the predetermined number of shots, so that it is not necessary to change the aperture for each shot, so that bracket shooting under flash light is good. Can be performed.

Embodiment Hereinafter, the present invention will be described with reference to an embodiment shown in the drawings. FIG. 1 shows a main part of the embodiment in the form of circuit blocks, in which a microcomputer (1) forms the core of a camera system and controls various controls. The microcomputer (1) controls flash bracket photographing in which a flash light adjustment correction amount to be described later is changed for each release. The microcomputer (1)
DX circuit (2), display circuit (3), AE circuit (4), D / A conversion circuit (5), AV / TV setting circuit (6), photometric circuit (7),
A film winding circuit (8) and the like are connected, and exchange signals with these circuits. The DX circuit (2)
Detects the ISO sensitivity SV coded on the film when the film is mounted on the camera body and sends it to the microcomputer (1). The display circuit (3) receives display data from the microcomputer (1) and performs various displays. Here, it is assumed that the display circuit (3) is provided with an outer display portion provided with a display surface on the outer surface of the camera body and an inner display portion provided in the viewfinder window. It should be noted that, although not particularly limited to this, the light control shift amount in the case of flash bracket shooting described later is displayed on both the outer display unit and the inner display unit, but the number of bracket shootings is displayed only on the outer display unit. Is done. The AE circuit (4) performs exposure based on the exposure value AV calculated by the microcomputer (1) and the shutter speed TV. The D / A conversion circuit (5) changes the dimming control data output from the microcomputer (1) from a digital amount to an analog amount and supplies it to the dimming circuit (12). The dimming control data in this case is obtained by adding the DX circuit (2) film sensitivity SV to the dimming correction amount? SV ₁ given from. The AV / TV setting circuit (6) sets the exposure value AV and the shutter speed TV in the A, S, M modes among the P, A, S, M exposure modes. Where P
Represents a program mode, A represents an aperture priority mode, S represents a shutter speed priority mode, and M represents a manual mode. The photometric circuit (7) detects the amount of light from the subject. The film winding circuit (8) performs a winding operation after the release operation is completed for each frame of the film.

Various other operation switches are connected to the microcomputer (1). Among them, the AE switch (S _AE ) is one of the P, A, S, and M exposure modes described above.
The exposure mode is cyclically selected, for example, in the order of P → A → S → M → P every time the switch is turned on. Metering start switch (S ₁₎ is a switch that turns ON when the finger touches or half-press the shutter button, ON by the distance measurement and photometry of the photometry start switch (S _1), and a display or the like is started. (S ₂₎ is a release switch which is turned ON when the shutter button is pressed is or all pushed, the shutter release operation is started by the ON of the release switch (S _2). (9) is a shift amount setting switch for setting a unit amount for shifting the dimming correction amount, and selects either 0.5EV or 1.0EV. Reference numeral (10) denotes a number setting switch for setting the number of films to be bracketed, which can be selected from three, five, and seven. (11) is a bracket setting switch. When it is ON, bracket shooting is performed and OFF.
In this case, normal shooting is performed.

Next, the dimming control circuit (12) to which the dimming control data from the microcomputer (1) is given via the D / A conversion circuit (5) stops the flash (13) from emitting light. An operational amplifier (14) in which the output of the D / A conversion circuit (5) is applied to a (+) input terminal; and a (+) input terminal of the operational amplifier (14). And (−) a light receiving element (D ₁ ) composed of a photodiode connected as shown between the input terminals, and an output terminal of the operational amplifier (14) for logarithmically compressing the input of the operational amplifier (14). ) A diode (D ₂ ) connected between input terminals as shown in the figure, a transistor (Q ₁ ) that logarithmically expands the logarithmically compressed output voltage, a collector and a power supply (Vc
c) a capacitor (C ₁ ) connected therebetween for integrating the logarithmically expanded current, a switch (S ₁₁ ) for controlling the integration operation of the capacitor (C ₁ ), and an output of the collector of the transistor (Q ₁ ) And a comparator (16) receiving a reference voltage (V ₁ ) from a DC power supply (15) at a (+) input terminal and a (+) input terminal. The dimming circuit (12) is provided in the camera body.

Further, the dimming circuit (12) includes, for example, an X contact (SX) that is turned on when the front curtain of the focal plane shutter is completed and the shutter is fully opened, and that the X contact (SX) is turned on. emitting a start signal (ST ₁₎ a first terminal for providing a flash (13) to (T _1), and inverts the signal provided from the flash (13) through a second terminal (T ₂₎ (ST ₂₎ caused by third for transmitting a switch inverter (17) to be supplied to the control terminal of the (S ₁₎ (T _7), emission stop signal as the output of the (ST ₃₎ flash (13) side said comparator (16) Te Terminal (T ₃ ). On the other hand, the flash (13) xenon tube emitting unit including (19) and (18), the light emission stop signal (ST ₃₎ turned on by the emission stop section (S _12), the emission start section (S _13),
Delay circuit for outputting a low level after a predetermined time delay upon receipt of the light emission start signal (22), an inverter which gives a light emission start portion converts the light emission start signal of a low level to a high level (S ₁₃₎ (23), First, second and third terminals (T ₁ ) (T ₂ )
4 corresponding to (T _3), the fifth, sixth terminal _{(T 4) (T 5)} (T 6)
Has bets, the output terminal of the delay circuit (22) is connected to the fifth terminal (T _5).

Now, when the shutter button is pressed, the X contact (SX) is turned on at the same time when the shutter is fully opened, and a low-level light emission start signal (ST ₁ ) is generated, the delay circuit (22) outputs a low-level light after a predetermined time. A level signal is generated. Therefore, a high level is applied to the control terminal (T ₇ ) of the switch (S ₁ ) via the inverter (17), and this switch (S ₁ ) is turned off. On the other hand, in the flash (13), the light emission start signal (S
T ₁ ) is converted to a high level by the inverter (23) and applied to the light emission start section (S ₁₃ ). Therefore emission start section (S ₁₃₎ is turned on, the light emitting unit (18) emits light. Light from the subject accompanying the flash emission enters the camera body through the taking lens, and a part of it is film (FL)
The light is reflected by M) and strikes the light receiving element (D ₁ ). The light receiving element (D ₁ ) outputs a current according to the light intensity on the film surface.
This output current is a voltage that is logarithmically compressed by an operational amplifier (14) and the diode (D _2), applied to the base of the transistor (Q _1). The output current generated on the collector side of the transistor (Q ₁ ) charges the capacitor (C ₁ ). The charging voltage of this capacitor (C ₁ ) corresponds to the exposure level. When the capacitor (C ₁ ) is charged and its charged voltage reaches the reference voltage level (V ₁ ), the output of the comparator (16) goes high. This high level acts on the light emission stop section (S ₁₂ ) as a light emission stop signal (ST ₃ ),
The light emission of the xenon tube (19) is stopped. In this way,
When the proper exposure level is reached, the flash (13) stops emitting light, and the flash (13) dimming operation is completed.

In this case, the light emission stop point is (P ₁ ) in FIG. 2 when the dimming control data output from the microcomputer (1) is only the film sensitivity SV (that is, the dimming correction amount ΔSV ₁ = 0). If the dimming control data output from the microcomputer (1) becomes a small value when the dimming shift amount -ΔSV is added to the film sensitivity SV,
Even if the same amount of light strikes the light receiving element (D ₁ ), the operational amplifier (1
4) The potential at the output point drops, the collector current of the transistor (Q ₁ ) also decreases, and the charging time of the capacitor (C ₁ ) increases, and accordingly, the inversion of the comparator (16) (low level → high level) Therefore, the flash (13) stops emitting light at the point (P2) (see FIG. ₂ ).
This means that the amount of flash light is overexposed than initially expected to be proper. In FIG. 2, the vertical axis indicates the amount of light emitted from the flash, and the horizontal axis indicates time (t).

Conversely, if the dimming control data obtained by adding + ΔSV to the film sensitivity SV is output from the microcomputer (1),
Even when the same amount of light hits the light receiving element (D ₁ ), the potential applied to the base of the transistor (Q ₁ ) increases, and the collector current also increases accordingly, so that the charging time of the capacitor (C ₁ ) is shortened. Become. As a result, light emission stop of the flash (13) becomes faster reversal of the comparator (16) becomes (P ₃₎ points of the second figure. This is because the amount of flash light is underexposed.

In this embodiment, as will be described later, during flash bracket photography, the light control data output from the microcomputer (1) is 0 → −ΔSV (over) →
+ ΔSV (under) → −ΔSV × 2 → + ΔSV × 2 → ...
Data in which a dimming correction amount that changes for each release is added is output, and dimming control of the flash (13) corresponding to the data value is performed. Here, ΔSV is a unit shift amount set in advance by the shift amount setting switch (9), and in the case of this embodiment, is 0.5 EV or 1.0 EV.

Next, the operation of this embodiment will be described with reference to the flowcharts of FIGS. FIG. 3 shows the basic control of the microcomputer (1) in the flash bracket. When this routine is executed, the state of the photometry start switch (S ₁ ) is _first checked in a step. Here, when the switch (S ₁ ) is ON, the process proceeds to the step and performs the process of S ₁ ON. The S ₁ ON process will be described later in detail with reference to FIG. Metering start switch (S ₁ ) is OFF
In the case of, the process proceeds to a step, and it is determined whether or not the shift of the setting switch, that is, the shift amount setting switch (9) or the number of sheets setting switch (10) is ON. Here, if at least one of the switches (9) and (10) is ON,
Proceeding to the step, the subroutine of bracket setting shown in FIG. 4 is executed. This bracket setting routine is a routine for setting a unit amount relating to the correction component of the dimming control data output from the microcomputer (1), that is, either 0.5 or 1.0, or a routine for setting the number of films for bracket photographing. It is. If the switches (9) and (10) are both OFF in step, the process proceeds to step and it is determined whether or not the AE mode switch (S _AE ) is ON. Here, when the switch (S _AE ) is ON, the routine proceeds to step and executes the routine shown in FIG. This routine sets the exposure mode to one of P, A, S, M
When the setting is completed, the process returns. If the AE mode switch (S _AE ) is not ON in the step, return to the step and repeat the subsequent routine. The order of the steps need not be limited to the order described above, and may be arbitrarily selected.

Next, the bracket setting routine of the above step will be described with reference to FIG. In FIG. 4, first, in step (B-1), it is determined whether or not the number setting switch (10) is ON. When the switch (10) is ON, step (B-
Proceed to 2) and take the number of shots N for flash bracket shooting
Is set to 3, 5, or 7. At this time, switch (1
Every time 0) is turned on, the number of sheets can be cyclically selected as 3 → 5 → 7 → 3. Thereafter, the process proceeds to step (B-5) to initialize the number N _{1 of} images shot with the flash bracket and the dimming correction amount ΔSV ₁ (N ₁ = 0, ΔSV ₁ = 0).
Then, the process returns. Step (B-1)
If the number setting switch (10) is OFF at step (B)
Proceeding to -3), it is determined whether the shift amount setting switch (9) is ON. Here, when the switch (9) is ON, the unit shift amount ΔSV is set to either 0.5 or 1.0 in step (B-4). Then, after that, the step (B-
Proceed to 5). If the shift amount setting switch (9) is OFF in step (B-3), the process returns. If the number setting switch (10) is operated, the process proceeds to step (B-2).
→ (B-5) → Return, and when the shift amount setting switch (9) is operated next (in this case, normally, the number setting switch is not operated), step (B-5)
1) → (B-3) → (B-4) → (B-5) → Return.

Next, the routine of the S ₁ ON process will be described with reference to FIG. In this routine, first, in step (# 1), the brightness BV of the subject is received from the photometry circuit (7) in order to determine the exposure. Then, proceed to step (# 2)
The film speed SV is input from the DX circuit (2). And
The exposure EV is calculated from the subject brightness BV and film sensitivity SV.
It is calculated based on the equation EV = BV + SV (step # 3).

Next, in step (# 4), the preset aperture AVS and shutter speed TVS are input from the AV / TV setting circuit (6), and the flow advances to the next step (# 5). In step (# 5), it is determined whether the selected exposure mode is the P mode. If the exposure mode is the P mode, the control aperture value AVC and the control shutter speed TVC corresponding to the exposure amount EV are calculated from the program diagram. (Step # 6). Here, since the program diagram is well known, its description is omitted. Then, step (#
Proceed to 13). If the mode is not the P mode in the step (# 5), it is determined whether or not the mode is the S mode in the step (# 7). If the mode is not the S mode, the process further proceeds to the step (# 9) to determine whether or not the mode is the A mode. If the mode is not the A mode, the exposure mode is the remaining M mode.
The AVS and TVS set above are used as they are, and the process proceeds to step (# 13).

If it is determined in step (# 7) that the mode is the S mode, the control aperture value AVC is set to AVC = EV by EV and TVS in step (# 8).
-Control shutter speed TVC obtained from TVS is set as TVC = TVS, and then the process proceeds to step (# 13). If it is determined in step (# 9) that the mode is the A mode, in step (# 10), the control shutter speed TVC is set to TVC = EV from the EV and AVS.
Calculated from −AVS, the control aperture value AVC is set to AVC = AVS, and then the process proceeds to step (# 13).

In step (# 13), it is determined whether or not the flash bracket shooting mode is set. If the flash bracket shooting mode has been set in advance by the bracket setting switch (11), the determination in this step (# 13) is YES, so the process proceeds to step (# 14) to control the shutter speed.
Match the maximum speed TVX to tune the TVC to the flash (TVC = TVX). Next, in step (# 15), it is determined whether or not the exposure mode is any of the P, S, and A modes. If any of the exposure modes, the mode is further set to P, S in step (# 16). Determine whether any of S, P, S
In either case, the control aperture value AVC is recalculated from EV and TVX in step (# 17), while the control shutter speed TVC is kept at the tuning maximum speed TVX. If it is neither P nor S in step (# 16), the mode is the A mode. In step (# 18), the control aperture value AVC is set to the set aperture value AVS.
On the other hand, the control shutter speed TVC is kept at TVC = TVX. If NO in step (# 15), the mode is the M mode. In this case, since the exposure is left to the photographer, AVC and TVC are controlled as they are in step (# 19). After the setting of AV and TV for each exposure mode is completed, they are displayed using the display circuit (3) in step (# 20).
If the mode is not the flash bracket photographing mode in the step (# 13), the process directly proceeds to the step (# 20), and any one of the aperture value and the shutter of the steps (# 6), (# 8), (# 10) and (# 11) is performed. Displays the speed according to the exposure mode. If display in step (# 20) is made, then step release switch proceeds to (# 21) (S ₂₎ and determines whether ON. If the release switch (S ₂ ) is OFF, it is determined in step (# 22) whether or not the flash bracket shooting mode is set. If not, the number N _{1 of} flash bracket shots and the dimming correction amount ΔSV _{1 are set.}
Are set to the initial state (N ₁ = 0, ΔSV ₁ = 0), and the routine returns. Here, the initial setting and the steps (B-
The initial setting in 5) is to set N ₁ = 0 and ΔSV ₁ = 0, but their significance is different. That is, the initial setting in the step (B-5) in FIG. 4 is not performed unless the number setting switch (10) or the shift amount setting switch (9) is turned on, whereas the initial setting in FIG. This is because the initial setting in step (# 23) is performed in a routine when the photometry start switch (S ₁ ) is turned on regardless of whether the switches (9) and (10) are turned on. It is necessary to reset (initialize) N ₁ and ΔSV ₁ when the bracket setting switch (11) is turned off during the bracket shooting and the bracket shooting is stopped, for example. It is.

The release switch (S ₂ ) is turned on in the step (# 21)
If it is determined that the flash bracket shooting mode is set, the process proceeds to step (# 24).
Here, if not in the flash bracket photographing mode, N ₁ and ΔSV ₁ are initialized in step (# 25) based on the same reason as in step (# 23). When the initialization in step (# 25) is completed, the process proceeds to step (# 28).
Step (# 24) if it is determined that the flash bracket shooting mode, the number of shots N ₁ in the next step (# 26) determines whether 0 or not, N ₁ = 0 unless step (# Proceeding to 28), if N ₁ = 0 (initial state), set ΔSV ₁ = 0 in step (# 27) so that ΔSV ₁ also matches the initial state, and proceed to step (# 28).

Step (# 28) the microcomputer (1) is calculated on the basis of the electronic flash light quantity (light adjustment control data) SVF from film sensitivity SV and exposure compensation amount? SV ₁ to SVF = SV +? SV _1. Subsequently, in step (# 29), the calculated flash light intensity SVF is output and given to the D / A conversion circuit (5). Thereafter, a release operation is performed (step # 30). In the accompanying step (# 31), exposure is performed based on AVC and TVC, and after the exposure is completed, the next step (# 3) is performed.
In 2), the film winding circuit (8) is driven to wind the film by one frame.

Next, it is determined whether or not the mode is the flash bracket shooting mode (step # 33). If the mode is not the bracket mode, the process proceeds to step (# 49) and returns. )
Waits for the photometry start switch (S ₁ ) to be turned off, and when the switch (S ₁ ) is turned off, the number of shots N ₁ is incremented by ₁ in step (# 35), and the next step (# 3)
6), following the assumption that performs the photographing number N ₁ is determined whether equal to the number N set in advance, flash bracket shooting is further flash bracket shooting since it is not yet completed the planned to be equal Dimming correction amount ΔSV
_In order to determine ₁ , the value of N1 is determined in step (# 37). By the way, in the present embodiment, the flash bracket photographing is performed by sequentially changing the light control correction amount ΔSV ₁ from 0 to −
ΔSV ₁ (over) → + ΔSV ₁ (under) → -ΔSV ₁ ×
Is performed _{2 → + ΔSV 1 × 2 →} ... is varied so on, is all you need is the determination of N _1. Then, step when N ₁ is determined to an odd number in (# 38), step (# 39)
? SV ₁ = a? SV ₁ advances to - (N + 1) calculated in × SV / 2, the flow advances to step (# 41). When N ₁ is an even number at step (# 38), the routine proceeds to step (# 40) to the willing to calculate the? SV ₁ =? SV ₁ at N ₁ × _ΔSV / 2 step (# 41). Step (# 4
In 1), the next photographing number and the light control correction amount are displayed on the display circuit (3). Then, it waits for 5 seconds to elapse (step # 42), and after 5 seconds, proceeds to step (# 49) and returns. Therefore, in this case, the display is performed for 5 seconds. However, if any key is turned on in the middle, the process returns without waiting for 5 seconds to elapse to prioritize the execution of the function by turning on this key (steps # 43 and # 4).
9).

Since it is that bracketing appointments when photograph number N ₁ in step (# 36) is determined to be equal to the set number N are completed, step photomeasurement switch (# 44) (S ₁₎ Wait until is turned off. Then, when the photometry start switch (S ₁ ) is turned off, step (# 45)
Initializes N ₁ and ΔSV ₁ respectively, and proceeds to the next step (# 4
At 6), the end of bracket shooting is displayed on the display unit of the display circuit (3). Then, after such display is performed for 5 seconds (step # 47), the process returns (step # 4).
Four). If any key is turned on before the lapse of 5 seconds, the process immediately returns to give priority to the execution of the function by turning on the key (# 48).

As described above, in the present embodiment, in the flash bracket photographing mode, the light control amount of the light control circuit (12) for controlling the light of the flash (13) is based on the light control correction amount output from the microcomputer (1). The light emission amount of the flash is changed (switched) one by one by changing the aperture, and the aperture is not changed.

Effect of the Invention According to the present invention, since the flash emission is switched for each image under the set aperture and shutter speed and the bracket shooting is performed, the aperture value may be kept at the set value, and therefore the aperture value may be changed for each image. This eliminates problems such as a change in the depth of field, and the shutter speed does not need to be changed, so good bracket shooting is not affected by factors such as tuning speed and camera shake limits. it can.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing a main part of a camera system embodying the present invention, and FIG. 2 is a diagram for explaining the control of the flash light emission amount, FIGS. 3, 4, and 5. FIG. 6 is a flowchart showing the operation. (1) microcomputer, (5) D / A conversion circuit, (11) bracket setting switch, (12) dimming circuit, (13) flash, (14) arithmetic amplifier.

Continuing from the front page (72) Inventor Naohiro Kageyama 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Prefecture Osaka International Building Minolta Camera Co., Ltd. (72) Masayasu Hirano 2-chome Azuchicho, Chuo-ku, Osaka-shi, Osaka No. 3-13 Osaka International Building Minolta Camera Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) G03B 7/16 G03B 15/05

Claims (2)

(57) [Claims] 1. A flash which emits flash light, an emission amount switching means for switching the flash emission amount of the flash, an aperture and a shutter speed determining means, and a flash and a shutter speed determining means for each sheet based on the determined aperture and shutter speed. Control means for switching the amount of light emitted from the flash to shoot a predetermined number of images. 2. The light-emitting device according to claim 1, wherein said light-emission-amount switching means has a light-adjustment means for adjusting the light of said flash, and switches the light-emission amount based on an output of said control means. Camera system.