JPH02154237A - Camera capable of driving lens during exposure - Google Patents

Abstract

PURPOSE:To obtain a special photographic effect even in the case of photographing with flash light by controlling a flash light emitting means so that the exposure of a main object with the aid of ordinary light may become nearly equal to flash light quantity. CONSTITUTION:An exposure calculation means 4 calculates the exposure of the main object with the aid of the ordinary light Ev=Bv+Sv+1 based on the luminance of the main object Bv and the sensitivity value of film Sv and decides a stoop value Av and a shutter speed Tv so that Ev=Av+Tv may be satisfied. The flash light emitting means 5 gives the flash light quantity Ev-1 to the main object under the control of a flash light dimming means 6. Thus, the exposure of the main object with the aid of the ordinary light becomes equal to the flash light quantity. Therefore, a soft focus effect which is reduced as compared with a case where photographing is performed only with the ordinary light is given to the main object to which the flash light contributes and the soft focus effect same as a case where the photographing is performed with the ordinary light is given to a background part to which the flash light does not contribute.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a camera that can drive the lens between exposures, and for example, uses an eye reflex camera to take fantastic photographs with special photographic effects. It is suitable for

[Prior Art] Conventionally, there have been commercially available cameras in which a fantastic photograph with a special photographic effect can be obtained by driving a focusing lens to defocus while the shutter is open.

There are two types of expression effects obtained by such a camera that can drive the lens during exposure: a focus effect on the soft 1 due to an increase in the scattering circle diameter, and an image enlargement/reduction effect due to a change in focal length. The image obtained varies greatly depending on the amount of contribution.

If the contribution of the increase in the scattering circle diameter is very large, a depiction similar to that taken with a soft focus lens will be obtained, and if the contribution of the change in image magnification is very large, a depiction similar to that obtained by shooting with an inter-exposure zoom will be obtained. is obtained.

[Problems to be Solved by the Invention] In the above-mentioned camera in which the lens can be driven during exposure, special photographic effects are obtained by driving the lens while the film is being exposed. When taking pictures with a flash, if the flash light accounts for the majority of the time, since the flash light is instantaneous,
There is a problem that special photographic effects cannot be obtained by driving the lens.

The present invention has been made in view of these points, and its object is to enable special photographic effects to be obtained even during flash photography in a camera capable of driving the lens during exposure.

[Means for Solving the Problems] In the present invention, in order to solve the above problems, the first
As shown in the figure, in a camera that is equipped with a lens driving means 2 that drives a part of the photographic lens 1 (focusing lens la) during exposure, and obtains special photographic effects by driving the lens during exposure, the brightness BV of the main subject is A photometering means 3 for obtaining information, an exposure calculation means 4 for calculating the amount of exposure of the main subject using constant light based on the output of the photometering means 3, a flash emitting means 5 capable of illuminating the main subject, It is provided with a flash light control means 6 that controls the flash light emitting means 5 so that the amount of exposure of the main subject and the amount of flash light are approximately equal.

[Effect] Hereinafter, the operation of the present invention will be explained with reference to FIG.

The lens driving means 2 has a function of driving a part of the photographing lens 1 (focusing lens la) during exposure, and produces a special photographic effect such as a soft focus effect by driving the lens during exposure. . This lens driving means 2 can also be used as a lens driving means for performing automatic focus adjustment by driving the lens before exposure. The photometer 3 measures the photo area in order to obtain information regarding the brightness BV of the main subject. The exposure calculation means 4 calculates the exposure amount of the main subject due to constant light, Ev=Bv+Sv+1, based on the brightness Bv of the main subject and the film sensitivity value Sv, so that Ev=Av+Tv. To,
Decide the aperture value AV and shutter speed TV. Then, the flash light emitting means 5 applies the flash light Me of Evl to the main subject under the control of the flash light control means 6. As a result, the amount of exposure of the main subject due to constant light and the amount of flash light become equal. For this reason, for the main subject where flash light contributes, the soft focus effect is less than when photographed using only constant light, and for background areas where flash light does not contribute, the soft focus effect is applied using the same soft focus effect as when photographing using constant light. Can give a focus effect,
This creates an expressive effect that clearly separates the main subject from the background and makes it stand out.

[Embodiment] FIG. 2 shows a circuit configuration of a camera as an embodiment of the present invention. In the figure, μC is a microcomputer (hereinafter referred to as "microcomputer"), which performs calculations for exposure control and automatic focus adjustment, and sequence control of the entire camera.
T is a power supply battery, which supplies power to the microcomputer μC and its peripheral circuits. Xtal is an oscillator, and the microcomputer μC operates according to a clock signal determined by this oscillator XLa1.

The microcomputer μC is connected to various peripheral circuits and can exchange information with these peripheral circuits.

First, the DSP is a display circuit that receives display data from the microcomputer μC and performs necessary display.

Display contents include, for example, shutter speed, aperture value, exposure mode (normal mode or fantasy mode),
High brightness warning display, low brightness warning display, film counter,
There are focus indications, focus detection failure indications, etc.

FLC is a flash circuit built into a flash that is detachably attached to the camera body.

Fra Soche is equipped with a flash light switch FSW, and this flash light switch FSW has the following functions:
There are two states: 0N10FF.

The flash circuit FLC transmits information regarding ON10FF of the flash emission switch FSW to the camera body, and the camera body changes exposure control according to the data. Exposure control is performed so that the flash always emits light when the flash light emission switch FSW is ON, and exposure control is performed so that the flash always does not emit light when the flash light emission switch FSW is OFF.

FCC is a flash dimming circuit that controls the amount of flash light.It receives film sensitivity information from film sensitivity reading circuit DXC via microcontroller μC, and measures the amount of flash light incident from the lens according to that information. Then, when the amount of light reaches a predetermined amount, the light emission is stopped.

DXC is a film sensitivity reading circuit that reads film sensitivity information recorded on the film cartridge and transmits it to the microcomputer μC. This information is used for AE calculation in the microcomputer μC.

LMC is a photometry circuit, which divides the photographic screen into a plurality of photometry areas 81 to S6 and performs photometry as shown in FIG.
Sends the necessary data to the microcontroller μC. The microcomputer μC is
The brightness BV of the main subject is calculated as the average brightness of the photometric values in the central photometric areas 84 to S6, and necessary AE calculations are performed to calculate the aperture control value and control shutter speed.

AFC is an AF control circuit that includes a TTL phase difference detection method focus detection means that photoelectrically converts the subject light that has passed through the photographic lens and detects the defocus ff1DF that indicates the amount of defocus from the in-focus position. Information regarding JLDF is transmitted to microcomputer μC. M is a motor for driving the focusing lens of the photographing lens, and AF
The lens is extended and retracted under the control of a lens drive circuit housed in the control circuit AFC, and automatic focus adjustment is performed so that the defocus IDF before exposure is zero.

The motor M is also used to drive the focusing lens during exposure to drive the lens during exposure.

The ENC is an encoder that detects the amount of rotation of the motor M for driving the leaf orcus lens when it is driven, and sends pulses to the microcomputer μC in accordance with a predetermined amount of rotation of the motor M. The microcomputer μC has a built-in lens position counter for determining the amount of lens extension from the infinity position, which is the most retracted state, as an absolute amount. The value of this lens position counter is expressed as a pulse count number P, and is reset to P = 0 by an internal command when the lens is retracted to an infinite position, and when the lens is extended, an internal command It is counted up according to the pulse from the encoder ENC, and when the lens is retracted, it is counted down according to the pulse from the encoder ENC according to an internal command. When the lens is extended to the closest position,
The value of the lens position counter is P=P, and this maximum extension N P M differs depending on the lens, and at the time of zero focus, which is read from the lens circuit LEC to the microcomputer μC as lens-specific information, this lens position counter Information on the distance to the main subject and the imaging magnification can be calculated from the pulse count number P. Furthermore, when out of focus, information on the distance to the main subject and photographing magnification can be calculated from the pulse count number P by the lens position counter and the defocus amount DF detected by the AFillft1 circuit AFC ( Special application 1986-20
(See Application No. 6697).

The LEC is a lens circuit built into a photographic lens that is replaceably attached to the camera body. The lens circuit LEC stores unique information for each photographing lens, and transmits this information to the microcomputer μC.

Lens-specific information includes maximum extension amount PM, focal length rat, a small aperture @ (so-called open aperture value) A o
, maximum aperture value AVH1 conversion coefficient, etc. Here, the conversion coefficient is a coefficient for converting the defocus amount DF obtained by the AP control circuit AFC into the lens drive amount ΔP (change in pulse count number P). The microcomputer μC performs calculations for automatic exposure control and automatic focus adjustment based on information transmitted from the lens circuit LEC. In addition, when the photographic lens attached to the camera body is a zoom lens, the lens circuit LEC includes a zoom encoder that is linked to the zoom ring, changes information on the focal length f and conversion coefficients, and sends the information to the microcontroller μC. introduce.

Each input port IP, ~IP, of the microcomputer μC is pulled up to a "High" level by an internal resistor, and is connected to the ground level through a separate switch. When any switch is turned on, the corresponding input port becomes “Low” level, and the ○N of each switch
10 F F can be determined by the microcomputer μC. Each switch will be explained below.

SI is a photography preparation switch that is turned on when the release button is pressed down to the first step, and when this switch is turned on, each operation of photometry, exposure calculation, and automatic focus adjustment is started.

S2 is a release switch that is turned on when the release button is pressed down to the second step, and when this switch is turned on, an exposure control operation is started.

SMD is a mode changeover switch, and this switch S.

Fantasy mode is selected when D is ON, and normal mode is selected when D is OFF.0 In normal mode, the combination of aperture value AV and shutter speed TV is determined according to the normal program diagram, but fantasy mode In the mode, a combination of aperture value AV and shutter speed TV is determined according to a special program diagram (described later in the explanation of FIG. 5) so that a specific expressive effect can be obtained by driving the lens during exposure.

SAF is an auto/manual switch. When this switch SAF is ON, the autofocus mode is activated, which drives the lens to the in-focus position based on the focus detection result, and when the switch SAF is OFF, the focus mode is activated. A manual focus mode is selected in which only in-focus or out-of-focus is displayed based on the detection result and the lens is not driven.

Next, the overall operation of the camera will be explained with reference to the flowchart shown in FIG.

First, in #10, it is determined whether the photographing preparation switch S is turned on. At #10, the shooting preparation switch S1 is set to O.
If not N, the determination operation of #10 is repeated and no other operations are performed. If the photographing preparation switch S1 is ON in #10, the operations from #20 onwards are performed.

At #20, lens data unique to the photographing lens is input from the lens circuit LEC. This lens data includes
As mentioned above, the minimum aperture value AVO1, the maximum aperture value AVM,
The focal length 1r, the conversion coefficient K from the defocus amount DF to the number of feeding pulses ΔP, the maximum number of feeding pulses PM, etc. are included.

At #30, flash data is input from the flash circuit FLC. The flash data includes information regarding the 0N10FF state of the flash light emission switch FSW, so that the camera body side can know the ON/○FF state of the flash light emission switch FSW.

In #40, the defocus ff is sent from the AP control circuit AFC.
It receives the information of 1DF, calculates the driving amount ΔP and driving direction necessary to drive the focusing lens to the in-focus position according to this information, and sends the calculated driving amount ΔP and driving direction to the AF control circuit AFC.

At #50, a photometry command is given to the photometry circuit LMC to measure the brightness of the photometry areas 81 to S6, and the microcomputer μC receives the data and calculates the brightness Bv of the main subject from the central photometry area 84 to S6. Calculate. The brightness of this main subject By
is used for subsequent AE calculations.

In #60, it is determined whether the exposure mode is the normal mode or the fantasy mode by determining the ON10FF state of the mode switch SMD. #60
If it is determined that the mode is fantasy mode, #
61 and perform fantasy mode AE calculation.
The fantasy mode is an exposure mode for obtaining special photographic effects, and its details will be described later in the explanation of FIGS. 4 and 5. If it is determined in #60 that the mode is the normal mode, the process moves to #62 and AE calculation in the normal mode is performed. This calculation is well-known, and for example, the aperture value AV and shutter speed T can be adjusted depending on the brightness of the subject.
This is done to change V at a ratio of 1:1 within a controllable range, and since it is not directly related to the content of the present invention, a detailed explanation thereof will be omitted.

The process moves from #61 or #62 to #70, and it is determined whether the 0N10FF status of the release switch S2 is bad.

If release switch S2 is not ON in #70, #1
Return to 0 and repeat the same operation. If the release switch S2 is ON in #70, a release operation is performed in #8o, and the process ends.

Here, when fantasy mode is selected, in the release operation of #80, a unique expressive effect is created by driving the focusing lens to defocus while the shutter is open. It is. This effect is due to the effect of increasing the diameter of the circle of confusion (
effect of bokeh) and change in focal length (change in magnification due to
There are two effects (enlarging/reducing the image), and the resulting image changes greatly depending on the contribution ratio of each. If the contribution of the increase in the diameter of the circle of confusion is very large, a depiction similar to that taken with a soft focus lens will be obtained, and if the contribution of the change in image magnification is very large, a depiction similar to that obtained by shooting with an inter-exposure zoom will be obtained. is obtained.

Fantasy mode exposes a sharp, in-focus image for 1/4 of the total exposure time (i.e. shutter speed), and exposes a sharp image for the remaining 3/4 to achieve the desired soft focus effect over a wide brightness range. By defocusing the image in time, it is possible to obtain an image that has an overall flare and a soft atmosphere, and in which the details of the subject are adequately depicted.

FIG. 6 shows the intensity distribution of a defocused point image, FIG. 6(a) shows the point image intensity distribution of an out-of-focus image, and FIG. 6(1) shows the point image intensity distribution of a preferable soft-focus image.

By performing the above-described exposure control in the fantasy mode, the point spread intensity distribution shown in FIG. 4B is obtained. This point spread intensity distribution differs from the simple out-of-focus image shown in Figure (a), in that the intensity is concentrated in the central area, which is the nucleus. The larger the value, the sharper the image, but the shorter the defocus time, the less soft focus effect can be obtained at the same shutter speed. Therefore, the practical range will be narrowed.

FIG. 5 is a program diagram used for the AE calculation in fantasy mode #61. This program diagram is
It is designed to achieve the most desirable degree of soft focus effect determined from the results of subjective evaluation tests over a wide range of brightness as possible. This program diagram will be explained below.

First, let's start with the soft focus effect and shutter speed.
The relationship between aperture values will be explained. The degree of soft focus effect is determined by the width, width, and width of the point image due to defocus.
In other words, it is evaluated based on the diameter of the circle of confusion. In the case of optical approximation, the diameter of the circle of confusion δ is expressed by the following equation, where DF is the defocus amount and F is the F-number of the lens.

δ=DF/F...■From this equation, it can be seen that the diameter of the circle of confusion δ is inversely proportional to the F number of the lens. On the other hand, since the shutter speed determines the time it takes to drive the lens, the amount of defocus is determined by the shutter speed. This relationship is as follows. The time the shutter is open is t. Then, the time it takes to actually drive the lens is the time the shutter is open as described above. It is 3/4 of , and is expressed by the following formula.

L-(3/4)to...■
With respect to the time to drive this lens, the encoder ENC attached to the drive shaft of the lens is set to the 8th [ff1(a)
The number of pulses ΔP generated is 0, which generates the number of pulses ΔP shown in
The relationship between the amount of defocus and the amount of defocus DF differs depending on the lens.
The conversion coefficient is included in the information read into the camera body from the lens circuit LEC. The relationship between the number of pulses ΔP, the conversion coefficient K, and the defocus amount DF is expressed by the following equation.

ΔP=to-DF...■', D
F = ΔP/K...■Figure 8 (a
) is expressed as a function f(t
), D F = f<L>/K...
(2) As shown in FIG. 8(a), the number of pulses ΔP can be considered to be proportional to the lens driving time after a certain period of time has elapsed, and in this case, the function f(t) can be expressed by the following equation.

r(t)=a ・ shi+b
...■,', D F = (a-1+b)/
K - ■ Here, a and b are constants.

(2) By substituting the equation into the 0 equation, the following equation is obtained.

δ=(a-t+b)/(K-F)...■In other words, the diameter of the circle of confusion δ is the time the shutter is open to
-(4/3) It is proportional to L and inversely proportional to F number.

When controlling exposure, in order to increase the amount of exposure by 1, the time the shutter is open must change by 1.
Since the F number changes by 1/fi times, APEX
On a program diagram in which the aperture value AV is expressed as a function of the shutter speed TV using the values, the values of the diameters of the circles of confusion δ become equal on a straight line with a slope of -2. This is why, in the program diagram shown in Figure 5, the slope in the section C to d is set to -2. Exposure is controlled by a combination of aperture value AV and shutter speed TV. As the exposure value EV becomes smaller, both the aperture value AV and shutter speed TV become smaller along this line, but once the minimum aperture value of the lens reaches AVO, it is not possible to take an aperture value smaller than this. , the aperture value AV is the minimum aperture value AV.

While keeping the same value, reduce only the shutter speed TV.

Sections a to C in FIG. 5 correspond to this control, and in this section, the diameter δ of the circle of confusion is larger than the appropriate value a. On the other hand, when the exposure value EV increases, it is impossible to take a value exceeding the maximum aperture value AVM, so only the shutter speed TV is increased while keeping the aperture value AV at the maximum aperture value AVH. The interval e to r in FIG. 5 corresponds to this control, and in this interval the diameter δ of the circle of confusion is smaller than the optimum value.

On the other hand, regarding the shutter speed TV, the amount of lens driving during exposure can be ensured. The shutter speed is controlled so that it does not become less than the limit shutter speed that can secure the amount of drive to the corner field, that is, the end of either the closest shooting distance side or the infinite shooting distance side of the lens (determined by the driving direction). The sections d to e in FIG. 5 correspond to this control. Without this control, the lens would reach the end during the exposure and continue the exposure for the rest of the time in a non-stop manner, resulting in double exposure with the sharp image exposed in the initial focused state. This creates a very unsightly image. However, the fifth [3
As shown in section azb in
Even if the L groove is not formed, if the diameter of the circle of confusion δ is sufficiently large (as a result of subjective evaluation, it is 3000μ or more), a clear double image will not be formed, so the diameter of the circle of confusion δ is 3
Shutter speed TV only if there is 000μI11 or more
is set to the value of the TVL groove. In addition, the shutter speed T
V is controlled within the range of the maximum shutter speed TVM and minimum shutter speed Tvo of the camera.

Next, AE calculation in fantasy mode <#61)
The contents will be explained according to the flowchart shown in FIG. First of all, #100 has a Franche light-emitting switch FS.
Determine the 0N10FF state of W. When it is determined that the flash is turned off in #100, the process moves to #110 and the brightness of the main subject is changed.
and the film sensitivity value SV to control the camera from the exposure value E.
Calculate v using the following formula.

E v=B y+ S V ”'■
If it is determined in #100 that the flash light emission switch FSW is ON, the process moves to #120 and the exposure value EV for controlling the camera is calculated using the following equation.

E y= B y + S v + 1
(In other words, when the flash fires, in order to control the light intensity ratio of the flash light and the ambient light to 1:1, the exposure value for the ambient light is set to a value that is IEv under. Since it is not possible to achieve the soft focus effect that was originally intended for photography with light alone, the idea is to use constant light to achieve a soft focus effect.Flash light has an extremely short emission time, and the light emitted from the front of the focal brain shutter is Since the light emission starts when the curtain completes its travel, the light emission starts before the lens drive starts, and by the time the lens drive starts, the light emission has already stopped.Therefore, the flash light is smaller than the exposure amount. If the main subject occupies the majority of the time, the defocused image will not be exposed and a soft focus effect will not be obtained. Rather, it actively utilizes the function of eliminating the defocus effect of flash light, and reduces the soft focus effect on the main subject to which the flash light contributes, compared to when shooting with constant light. By giving the non-contributing background part a soft focus effect similar to that of a scene photographed under constant light, an expressive effect can be obtained that clearly separates the main subject from the background and makes it stand out.

Move from #110 or #120 to #200.

By determining the ON/FF state of the auto/manual switch SAF, it is determined whether the autofocus mode is set. If the switch SAF is not set to autofocus mode, it is not possible to drive the lens to obtain a soft focus effect, so the process moves to #1200 and a release prohibition process is performed. If it is determined in #200 that the switch SAF is set to autofocus mode, the process moves to #210 and the imaging 1Δ rate β of the main subject is calculated.

After that, the direction in which the lens is to be driven is determined in steps #300 to #350. First, in #300, the value of the conversion coefficient I( is 0.
It is determined whether it is 7 or more. If K≧0.7,
This means that the short focus range of the zoom lens is being used, and the process moves to #330. In #300, it is determined whether the maximum pulse number P is 3000 or more. Yes, #33
Transition to 0. #300 and not ≧0.7, and #
If PM≧300D is not satisfied in 310, it means that a normal photographic lens is being used, and the process moves to #320. In #320, the shooting magnification β of the main subject is (1/1
2) Determine whether it is more than twice as much, and if β<1/12, proceed to #340 and select a lens driving direction (i.e., extending direction) that defocuses in the near direction,
If β≧1/12, move to #350 and select the driving direction of the lens (that is, the renormalization direction) that defocuses in the far direction.0 With a normal photographic lens, the maximum possible imaging magnification is approximately Since it is a constant value, by switching the driving direction of the lens at a certain imaging magnification in this way, it is possible to switch the driving direction at a point at a substantially constant percentage of the lens's drivable range. Shooting magnification β
The value of (1/12) times corresponds to a position further on the extension side than the middle position of the drivable range, and only when the lens is extended beyond this position, the lens is driven in the extension direction, In all other cases, the drive is in the feeding direction. Thereby, the soft focus effect can be made to look more favorable. In other words, by moving the lens as far as possible, the bokeh will spread outward from the subject, and the background will also be out of focus, giving the entire screen a softer image. It is what it is.

On the other hand, if the short focus range (wide-angle side) of a zoom lens is used, the maximum imaging magnification will be smaller than that of a normal shooting lens, and if a macro lens is used, the maximum imaging magnification will be smaller than that of a normal shooting lens. Since it is larger than the lens, the precondition that the maximum photographic magnification is almost constant is no longer satisfied, and the lens drive direction cannot be appropriately determined by the judgment in 5#320. Therefore, in these cases,
The process moves from #300 or #310 to #330, respectively, and it is determined whether P N > P p. Here, P.

is the number of pulses that can be driven in the feeding direction, and PF is the number of pulses that can be driven in the feeding direction. P.

PF is a pulse count number P that indicates the current position of the lens (focus position), a pulse number PM that indicates the maximum drive distance of the lens, and a minimum pulse count number po (in this example) when resetting the lens position counter. It can be calculated from PO=O) using the following formula.

pN=pM-p ・・・■PF=P
-PO...@ If PN>PF in #330, it means that the number of drivable pulses PN in the edge direction is larger.
Move to #340 to select the lens driving direction (that is, the direction in which the lens is extended) that defocuses in the near direction, and conversely, if PN≦PF, move to #350 to defocus in the far direction. Select the driving direction of the lens (that is, the renormalization direction). Note that on the short focal length side of the zoom lens, the variable ta coefficient has a relatively large value, so #
In the determination of 300, if it is 20.7 or more, it is determined that the short focus range of the zoom lens is being used.

In addition, the macro lens is a lens with a large maximum extension amount, and the pulse number P, which indicates the maximum drive amount, is a large value, so in the judgment #310, if PM≧3000, the macro lens is used. It is something that is being judged.

The process moves from #340 or #350 to #400, and the value of the shutter speed TVL, which is the limit of the lens drive time shown in the program diagram of FIG. 5, is calculated.

If the drive direction determined in steps #300 to #350 is in the extending direction, use formula 0, and if it is in the retracting direction, use formula 0 to calculate the number of movable pulses.9 Calculate the number of movable pulses using the conversion table from the determined number of movable pulses. The value of shutter speed TVL, which is the limit of drive time, is calculated. This conversion table is based on the horizontal axis (number of pulses ΔP) in the function shown in Figure 8(b).
is an address and the value of the vertical axis (shutter speed TV) is stored in the r (0M table).The function shown in Figure 8 (b) is the inverse function of the function shown in Figure 8 (,). It is shown in APEX value.

Next, in #500 to #510, it is determined whether the exposure value EV calculated in #100 to #120 is within a range that allows exposure control. First, in #500, it is determined whether the exposure value EV is greater than or equal to the sum (Avo+Tvo) of the minimum aperture value Ay□ of the lens and the minimum shutter speed TvO of the camera, and
If v<jAvo+Tvo), the process moves to #1100 to issue a low brightness warning.

Next, in #510, the exposure value Ev is the maximum aperture f of the lens.
The sum of iaAvM and camera's maximum shutter speed TvM (
AVM+TVM) or less is determined, and E V> (A
VM and TvM) to issue a high-intensity warning #
1. Move to OOO. In other cases, since the exposure is within the controllable range, the process proceeds to #600.

In #600, the value of the shutter speed TvP corresponding to the 0 point shown in the program diagram is calculated. First, from the minimum aperture value AVO to the minimum F number Fo using a conversion table.
Next, calculate the defocus required to make δ = 1500μ apex from the following formula obtained by substituting Fo as the value of F in the 0 formula and 1500μ as the value of the diameter of the circle of confusion δ. , 1iDFP is determined.

DFp=1500XF.

And this defocus f! The number of lens driving pulses ΔPP required to obtain kDFP is determined from the following equation, which is a modification of the 0 equation.

ΔPP=DFPXK The shutter speed TvP corresponding to the 0 point is calculated from the determined number of lens drive pulses ΔPP using the function shown in FIG. 8(b) (the same ROM table used in #400).

Next, in #700 to #780, the aperture value AV and shutter speed T are used to control the camera according to the program diagram shown in FIG. 5 from the exposure value EV calculated in #100 to #120.
Determine the combination of V.

First, in #700, it is determined whether TVP≧TvL. If TVP<TVL at #700, TV at #710
Set it as P-TvL and move to #720. Also, #700
If TvP≧TvL, the process directly proceeds to #720. This is a process to prevent the above-mentioned double image from being formed when the diameter δ of the circle of confusion does not reach 1500 μm or more even if the lens is driven to its limit. #
At 720, it is determined whether Ev≦(A vo + T vp). If EV≦(Avo+Tvp) in #720, the aperture value AV and shutter speed TV are calculated using the following equations in #730, and the process moves to #900. This process corresponds to the control in sections a to C in the program diagram of FIG.

AV=AVO TV=Ev-AV If Ev≦(A vo+T vp) is not found in #720, the process moves to #740, and the aperture value AV and shutter speed TV are calculated using the following equations.

Av=2(Ev Tvp) Av.

TV2Ev-AV This process is carried out in sections C~ in the program diagram of FIG.
This process corresponds to the control of d and calculates a combination of aperture value AV and shutter speed TV such that the diameter of the circle of confusion δ is 1500 μIn. In #750, it is determined whether the shutter speed TV calculated in #74 and O is less than the shutter speed TVL, which is the limit of the lens drive time, and is h. #7
50, if T v < T VL, in #760, recalculate the aperture value AV and shutter speed TV using the following formula,
Move to #770.

This process is performed in the section d”e in the program diagram of FIG.
corresponds to the control of

TV=TVL AV=EV-TV If TV≧TvL in #750, move to #770,
It is determined whether the aperture value AV calculated in #740 or #760 is larger than the maximum aperture value AVM.

If A v > A VM in #770, the aperture value AV
Recalculate the shutter speed TV using the following formula and get #80
Transition to 0. This process corresponds to the control in sections e to r in the program diagram of FIG.

Av=AvM TV=EV-AV If AV≦AVM in #770, add one line to #800,
ON10 of the flash light emission switch FSW Determine the FF state 9 If the flash light emission switch FSW is OFF in #800, proceed directly to #900, and if it is ON, adjust the dimming level so that the flash exposure amount is IEv under. Set.

As a result, the main subject is properly exposed in combination with the exposure amount due to the constant light determined in #120.

In steps #900 to #930, it is determined whether or not special photographic effects using the fantasy mode can be obtained.

First, in #900, the diameter δ of the circle of confusion is calculated from the aperture value AV and shutter speed TV determined in steps #700 to 780. To calculate the value of the diameter of the circle of confusion δ, first calculate the defocus amount DF=f(t)/1(0
The function "(t)" indicating the number of pulses in the formula is a ROM that stores the number of pulses ΔP using the shutter speed t corresponding to the lens drive time E as an address, as shown in FIG.
The F-number is determined from a ROM table that stores the F-number using the aperture MAV as an address. 0 from the calculated defocus JiDF and F number
The value of δ-DF/F is calculated using the formula.

In #910, it is determined whether the diameter δ of the circle of confusion is less than 500 μm. Under conditions where the diameter of the circle of confusion δ is less than 500μ, it is determined that the soft focus effect cannot be obtained, and #1
If δ<500μ is not found in #910, it is determined in #920 whether the shutter speed TV is less than the shutter speed TVL which is the limit of the lens driving time. If TV≧TVL in #920, the lens does not reach the end while driving the lens during exposure, and this is a condition for obtaining special photographic effects, so the process returns directly.

If TV<TVL in #920, δ≧30 in #930
Determine whether or not it is 00μ. #930 and δ≧30
If it is 00μ, even if T y < T V L, the condition is such that a special photographic effect can be obtained, so the process returns as is. If δ<3000μ is determined in #930, it is determined that an undesirable double image will be formed, and the process proceeds to #1100.

At #1100, as shown in FIG. 9(a), “
"Lo" is displayed. This display can prompt the photographer to increase the brightness of the subject in some way. For example, it is possible to obtain a photographic effect by illuminating the subject. 3 #1000 In order to warn that the brightness is too high and the special shooting effect of fantasy mode cannot be obtained sufficiently, the character "I (■") is displayed as shown in Fig. 9(b). The photographer can be encouraged to lower the brightness of the subject in some way, and for example, by attaching a filter with a neutral density, it is possible to obtain a photographic effect.

#1200 avoids taking photos that do not have the special shooting effects of fantasy mode when the warning display of #1000 or #1100 is displayed or when it is determined that the AF mode is not available in #200. Therefore, a release prohibition process is performed, specifically, a release prohibition flag is set, and as a result, release in fantasy mode is prohibited in the process of #80 (see FIG. 3).

[Effects of the Invention] According to the present invention, in a camera equipped with a flash light emitting means and capable of driving a lens during exposure, the flash light emitting means is controlled so that the amount of exposure of the main subject by constant light and the amount of flash light are approximately equal. As a result, the effect of the special photographic effect by driving the lens during exposure can be made different between the main subject to which the flash light contributes and the background part to which the flash light does not contribute, and it is possible to obtain photographs with unique expressive effects. be able to.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of the present invention, FIG. 2 is a block circuit diagram of a camera as an embodiment of the present invention, FIG. 3 is a flowchart for explaining the overall operation of the same, and FIG. 4 is a flowchart for explaining the contents of AE calculation in fantasy mode as above, Fig. 5 is a diagram showing the AE program in fantasy mode as above, and Fig. 6 (a) is point image intensity of out-of-focus image. Figure 6 (11) is a diagram showing the distribution, and Figure 7 is a diagram showing the photometric area of the photometric circuit used in the above camera. ) and (b) are diagrams showing the relationship between the number of pulses and shutter speed during exposure lens driving, and FIGS. 9(a) and (b) are explanatory diagrams illustrating warning displays used in the same camera. 1 is a photographic lens, 1a is a focusing lens, 2 is a lens drive means, 3 is a photometry means, 4 is an exposure calculation means, 5 is a flash light emitting means, and 6 is a flash light adjustment means.

Claims (1)

[Claims] (1) In a camera that is equipped with a lens drive means that drives a part of the photographic lens during exposure, and which obtains special photographic effects by driving the lens during exposure, there is a light metering means for obtaining information regarding the brightness of the main subject, and a light metering means for obtaining information regarding the brightness of the main subject. An exposure calculation means that calculates the amount of exposure of the main subject to constant light based on the output, a flash emitting means that can illuminate the main subject, and a flash that calculates the amount of exposure of the main subject to the constant light and the amount of flash light. 1. A camera capable of driving a lens during exposure, comprising: a flash dimming means for controlling a light emitting means.