JP3212164B2 - Camera photometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photometric device for a camera,
More specifically, the present invention relates to a photometric device for a camera that can switch between normal shooting with a standard screen size and trimming shooting with a shooting range narrower than this shooting range.

[0002]

2. Description of the Related Art Hitherto, various proposals have been made for a photometric device of a camera capable of switching between normal photographing and trimming photographing. For example, USP Re. As shown in Japanese Patent No. 32,797, during trimming, photometry of a trimming range is performed by photometric means, and the photometric value is subjected to parameter correction by exposure control means to obtain accurate exposure. Further, as shown in US Pat. No. 4,943,825, a photometry is performed on a range substantially corresponding to a photographing range of the trimming photography mode regardless of the standard photography mode and the trimming photography mode, and the exposure is performed on the photometric value. There is something to get.

[0003]

However, the above USP
The technical means of Re32,797 has a disadvantage that the light measurement range is narrowed during trimming photographing, so that the luminance limit value of light measurement at low luminance is reduced. In addition, the US
In P 4,943,825, in the standard shooting mode where shooting is often performed, the tendency of center-weighted metering in the trimming shooting range becomes strong, and the brightness at the periphery of the angle of view is different from the brightness at the center. Does not have the proper exposure, and
There is a problem that the luminance limit value of photometry at the time of low luminance decreases.

An object of the present invention is to provide a camera capable of switching the field of view in a finder between a normal photographing mode having a standard screen size and a trimming photographing mode. It is an object of the present invention to provide a photometric device for a camera that can obtain an accurate photometric value as in normal photographing without lowering the luminance limit value of the camera.

[0005]

SUMMARY OF THE INVENTION A first turtle according to the present invention is provided.
The photometric device of the camera
Field and viewfinder field of view in trimming shooting mode
When the camera is set to the trimming shooting mode, the viewfinder field of view other than the viewfinder field corresponding to the screen area used for printing
The transmittance of the portion is changed between the first transmittance state and the second transmittance state.
A finder state setting means that can be set to one of the above , a photometric means disposed in the finder optical path to measure the amount of light transmitted through the finder visual field ,
In this case, the viewfinder status setting
The field of view in the first transmittance state changed by the step
Including photometry data obtained by photometry of the finder field of view, and
The second viewfinder changed by the viewfinder state setting means.
The above viewfinder field including the field of view in the transmittance state is measured.
Of the light transmission data, and the first transmission light
Based on the ratio of the transmittance in the excess transmittance state to the transmittance in the second transmittance state.
The file corresponding to the screen area used for printing
And a photometric value calculating means for calculating a photometric value corresponding to the indian field of view . Also according to the invention
The photometric device of the second camera is a camera in the normal shooting mode.
Finder field of view and file
In a photometric device of a camera that can observe the
When the camera is set to the rimming mode, it is
Other than the viewfinder field corresponding to the screen area used.
Viewfinder that allows changing the transmittance of the indian field of view
State setting means and a finder
Photometric means for measuring the amount of light transmitted through the
In the shooting mode, the photometry
Before the transmittance is changed by the binder status setting means
Of the viewfinder field including the field of view
It is changed by optical data and further by the finder status setting means.
Metering the viewfinder field including the updated field of view
Of the measured photometric data and the transmittance change
Based on the ratio of the transmittance before and after the above change,
Viewfinder corresponding to the screen area used
A photometric value calculating means for calculating a photometric value
It is characterized by.

[0006]

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a schematic configuration diagram of an optical system of a single-lens reflex camera capable of performing trimming photographing according to a first embodiment of the present invention.

A movable reflecting mirror 2 constituting a finder optical system is rotatably supported on an upper end 2a behind the photographing lens 1 held in a lens barrel of a camera body (not shown). At an angle of 45 degrees.
A focusing screen 3 for forming a subject image from the photographing lens 1 is disposed above the movable reflecting mirror 2. Immediately above the focusing screen 3, the focusing screen 3 approaches the screen 3 and a finder is provided. An LCD panel 4 is provided as a finder field mask for switching the field of view into a field of view of a normal shooting screen size and a trimming field of view of a smaller screen size.

As shown in FIG. 2, the LCD panel 4 switches to a state of a total of three visual field ranges of a standard photographing mode and two states in a trimming photographing mode. That is, in the standard shooting mode, as shown in FIG. 2A, the entire LCD panel 4 is in a transparent state. Also, in the trimming photographing mode, FIGS.
As shown in FIG. 4, the range 4a (hereinafter, referred to as a trimming mask range) of a strip-shaped portion (hereinafter, referred to as a trimming mask) of the upper and lower portions of the LCD panel 4 of the trimmed screen is a fine dot pattern. 2B, the transmissivity of light is high (hereinafter referred to as high transmissivity), and the dot density is higher and the light transmission rate is lower than in FIG. 2B. The state where the light transmittance is low (hereinafter referred to as low transmittance) (FIG. 2)
(C)). In this embodiment, a description will be given of a so-called panoramic shooting in which the horizontal dimension is the same as the normal shooting and the vertical dimension is reduced as the trimming shooting.

Returning to FIG. 1, a pentaprism 5 is disposed above the LCD panel 4, and an eyepiece 6 is disposed behind the pentaprism 5. And
Behind the pentaprism 5 and near the eyepiece 6, a photometric lens 7 for measuring the brightness of the subject is provided.
In addition, light receiving elements 8 for photometry are respectively provided behind them.

In a camera capable of performing trimming photographing having the optical system configured as described above, the photographing lens 1 is used.
Is reflected upward by the movable reflecting mirror 2 obliquely provided on the optical axis of the photographing optical system, and forms a subject image on the focusing screen 3. This subject image is observed by the eyepiece 6 via the LCD panel 4 which is in a fully transparent state in the normal photographing mode. The light beam from the subject image on the focusing screen 3 is condensed on the photometric light receiving element 8 by the photometric lens 7 disposed behind the pentaprism 5, and the luminance of the subject image is measured. Is done. The photometric lens 7 and the photometric light-receiving element 8 are arranged such that the photometric range at this time is the entire or almost entire surface of the focusing screen 3 corresponding to the standard photography range in the normal photography mode.

The viewfinder range in the trimming photographing mode is regulated by the LCD panel 4 disposed above the focusing screen 3. In the normal photographing mode, as shown in FIG. 2A, the L corresponding to the entire screen of the focusing screen 3 is adjusted.
Since the area of the CD panel 4 is in a transmissive state, the observation of the subject image and the photometry of the subject are performed by the focusing screen 3.
Is done in the whole range.

On the other hand, at the time of photometry in the trimming photographing mode, as shown in FIGS. 2B and 2C, a finder visual field corresponding to the trimming range is obtained. The LCD panel 4 is driven so as to alternately switch between the state (FIG. 2B) and the low transmittance state (FIG. 2C). Thus, the subject light image on the focusing screen 3 is transmitted through the trimming range 4b of the LCD panel 4 as it is, but is weakened when the light is transmitted through the trimming mask range 4a of the LCD panel 4. For this reason, the image of the subject on the focusing screen 3 is adjusted to the trimming range 4b.
In the trimming mask range 4a, the image can be observed clearly in the trimming mask range 4a. Therefore, in the trimming photographing mode, the photometric light amount condensed on the light receiving element 8 increases when photometry is performed on the entire viewfinder including the trimming mask range 4a, rather than when photometry is performed only on the trimming range 4b.

FIGS. 3 and 4 show the subject in the finder and the field of view in the normal photographing mode and the trimming photographing mode. In the standard photographing mode, as shown in FIG. 3, the entirety of the focusing screen 3 serves as a finder visual field 9, which the photographer observes. Also,
In the trimming photographing mode, the viewfinder state of the entire finder corresponds to the state of the LCD panel 4, and the trimming mask range of the finder has a high transmittance state (FIG. 4A).
And the low transmittance state (FIG. 4B). FIG.
As shown in (A), when the trimming mask range 9a of the finder is in a high transmittance state, the range 9a is slightly darker than the trimming range 9b, and a subject in the entire view range of the finder is observed. Further, when the LCD panel 4 is switched, as shown in FIG. 4B, when the trimming mask range 9a of the finder is in a low transmittance state, the range 9a is darker than the trimming range 9b, and the entire finder is in a state. The subject in the range is observed.

In the trimming photographing mode, the LCD mask 4 alternately switches between a high transmittance state and a low transmittance state in the trimming mask range 4a. The trimming mask range 9a shown in FIG. 4B has a high transmittance state shown in FIG.
The state is alternately switched to the low transmittance state shown in FIG.

Photometry in the normal photographing mode is performed when the entire LCD panel 4 is in a light transmitting state. For example,
If the photometry method is average photometry, photometry is performed on the entire range of the finder. The photometry in the trimming photographing mode is performed when the trimming mask range 4a of the LCD panel 4 is in each of the high transmittance state and the low transmittance state. The photometric light amount in the trimming photographing mode is smaller than the photometric light amount in the normal photographing mode by the light-shielding dot pattern of the LCD panel 4.
Although the amount of light condensed on the LCD panel slightly decreases,
The amount of light is much larger than that in the photometry in a completely shaded state in the trimming mask range 4a.

FIG. 5 is a block diagram showing a configuration of an electric circuit built in the camera capable of performing trimming photographing according to the present embodiment. From the CPU 11 that controls the operation of the camera,
A signal for controlling film winding and rewinding is sent to the film feed control circuit 12, and a signal for controlling autofocus (AF) is sent to the AF control circuit 13.
Further, a signal for driving the zoom / focus lens of the photographing lens (see FIG. 1) is transmitted to the lens drive control circuit 14.
To be output to each. The above C
The PU 15 has a switch 15 for starting the AF operation.
And a switch 16 for starting the exposure sequence after the completion of the AF operation are connected between GND.

A switch SW18 for switching between the normal photographing mode and the trimming photographing mode is connected to GND in the trimming switching control circuit 17,
The mode switching signal from the switch 18 is input from the trimming switching control circuit 17 to the CPU 11.
The trimming switching control signal from the trimming switching control circuit 17 is output to an exposure mask switching control circuit 19, and the exposure mask switching control signal from the exposure mask switching control circuit 19 is supplied to a film exposure mask member (not shown) and its drive. It is output to the system and switches the exposure range of the film. Further, the trimming switching control signal from the trimming switching control circuit 17 is applied to the LCD panel driver 2.
The LCD panel 4 switches the field of view in the finder.

A signal for controlling the exposure from the CPU 11 is input to an exposure control circuit 21, and a trimming switching control signal is also input from the trimming switching control circuit 17 to the exposure control circuit 21. The exposure control circuit 21 outputs a signal for driving a mirror, a shutter, and an aperture to a mirror / shutter / aperture drive circuit 22, which drives a mirror, shutter, and aperture (not shown). Exposure control circuit 2
An exposure control signal for controlling photometry is output from 1 to the photometry control circuit 23. The photometry control circuit 23 outputs the subject brightness measurement value measured by the photometric light-receiving element 8 via the exposure control circuit 21. The data is input to the CPU 11.

The exposure control circuit determines the shutter speed and the aperture value from the photometric value measured by the photometric light-receiving element 8. In the normal photographing mode, the exposure control circuit 21 calculates the shutter speed and the aperture value from the parameters in the normal photographing mode based on photometric values obtained by measuring the entire range of the finder, and controls the exposure.

Next, the means for calculating the photometric value in the trimming photographing mode will be described with reference to FIG. FIG. 6 shows, for example, that the trimming mask range of the LCD panel 4 has a high transmittance state (FIG. 6A) and a low transmittance state (FIG. 6A).
FIG. 9 shows an example of calculating a photometric value of a trimming range a from a photometric value obtained by photometry in the case of (B)).
That is, when the trimming mask range of the LCD panel 4 has a high transmittance, the photocurrent of the photometric light-receiving element 8 is I, and when the transmittance is low, the photocurrent is I '. Assuming that the ratio of the transmittance value is ΔK and the photocurrent in the trimming range a to be obtained is Ia, the photocurrent in the high transmittance range b is Ib, and the photocurrent in the low transmittance range b ′ is Ib ′, Ia + Ib = I... (1) Ia + Ib ′ = I ′ (2) Ib ′ / Ib = ΔK (3) From the above equations (2) and (3), Ia + ΔK · Ib = I ′ (4) From the above equations (1) and (4), Ia + ΔK · (I−Ia) = I ′ Ia · (ΔK−1) = ΔK · I−I ′ Ia = (ΔK · I−I ′) ) / (ΔK−1), and the photometric value (photocurrent value) Ia measured in the trimming shooting range is L The photocurrent I of the photometric light-receiving element 8 when the trimming mask range 4a of the D panel 4 is high transmittance, the photocurrent I 'when the transmittance is low, and the ratio of the low transmittance value to the high transmittance value. It is calculated by ΔK. FIG.
Shows this in a diagram, in which the vertical axis is the photocurrent value, and the horizontal axis is the transmittance of the translucent trimming mask range of 1
The area of the entire viewfinder through which light is transmitted is shown in terms of 00%, and the area of the trimming mask is 2b in the high transmittance state, 2b 'in the low transmittance state, and a in the trimming photographing range. I do. The intersections of the converted areas a + 2b and a + 2b 'respectively corresponding to the photocurrents I and I' are connected and extended in the direction of the area a of the trimming range,
The point where the area a intersects is the photocurrent value Ia to be obtained. Then, using the photocurrent value Ia, the exposure control circuit 2
In step 1, a shutter speed and an aperture value are calculated based on parameters corresponding to the trimming shooting mode.

The operation of the camera having such a circuit configuration will be described with reference to the flowchart of FIG. This flowchart is a subroutine in photometry. The sequence starts, and in step S1, it is determined whether or not the camera is in a trimming shooting mode. If the camera is not in the trimming shooting mode, the process proceeds to step S14. If the camera is in the trimming shooting mode, the process proceeds to step S2. Switching of the trimming photographing mode is performed by the switch 18
(See FIG. 5) to turn on the trimming switching control circuit 1
7.

When the mode is switched to the trimming photographing mode,
In step S2, the LCD panel 4 is driven to switch the trimming mask range of the LCD panel 4 to a high transmittance state. In the high transmittance state, in step S3,
The first photometry (D1) of the entire finder is performed. The photometric data D1 obtained by the photometry is stored in the memory of the CPU 11 in step S4.

In step S5, the LCD panel 4 is driven to switch the trimming mask of the LCD panel 4 to a low transmittance state. In this low transmittance state, step S
At 6, the second photometry (D2) of the entire finder is performed.
The photometric data D2 obtained by the photometry is stored in the CPU 11 in step S7. Then, step S8
The aperture calculated by using the photometric data D1 in the high transmittance state of the trimming mask and the photometric data D2 in the low transmittance state of the trimming mask stored in the memory of the CPU 11 The Av apex value and the Tv apex value respectively corresponding to the set value and the shutter speed are stored in storage means such as a RAM (not shown).

In step S9, if the switch 16 (see FIG. 5) for starting the exposure sequence is not turned on for a predetermined time, the process returns to step S2, and the loop of steps S2 to S9 is repeated until the switch 16 is turned on. Is repeated. When the switch 16 is turned on and the exposure sequence is permitted, the process proceeds to step S10, and the process proceeds to step S10.
At step S12, an exposure operation is performed. That is, step S
10, the mirror / shutter / aperture drive circuit 2
2 (see FIG. 5), the movable reflection mirror 2 is raised, and then, in step S11, the aperture is set, and in step S12, the shutter is opened and closed, and the Av apex value and Tv apex value are set. , An appropriate exposure operation is performed by the exposure control circuit 21 in the trimming shooting mode. When the exposure operation is completed, in step S13, the aperture is returned to the open state, the movable reflection mirror is lowered to a predetermined position, and the exposure sequence in the trimming photographing mode ends.

Returning to step S1, if the mode is not the trimming photographing mode, that is, if the mode is switched to the normal photographing mode, in step S14, the LCD panel 4 is driven to switch off the trimming mask, thereby turning off the LCD. The panel 4 is made entirely transparent. In this state, the photometry (D3) of the entire finder is performed in step S15. In step S16, the Av apex value and the Tv apex value corresponding to the aperture setting value and the shutter speed, respectively, calculated by using the photometric data D3 obtained by the photometry are stored in the memory of the CPU 11.

In step S17, if the switch 16 (see FIG. 5) for starting the exposure sequence is not turned on for a predetermined time, the process returns to step S15, and the switch 1
Steps S15 to S17 until 6 is turned on
The photometry and the photometry calculation are repeated in the loop. When the switch 16 is turned on and the exposure sequence is permitted, the process proceeds to Step S18, and Steps S18 to S20 are performed.
Perform the exposure operation with. That is, in step S18,
The movable reflection mirror 2 is raised by the mirror / shutter / aperture drive circuit 22, then the aperture is set in step S19, and in step S20,
The shutter is opened and closed, and an appropriate exposure operation is performed by the exposure control circuit 21 in the normal shooting mode based on the Av apex value and the Tv apex value stored in the memory of the CPU 11. When the exposure operation is completed, in step S21, the aperture is returned to the open state, the movable reflection mirror is lowered to a predetermined position, and the exposure sequence in the normal shooting mode ends.

As described above, in the first embodiment, the photometry in the trimming photographing mode is performed not only for the trimming photographing range but also for the entire range of the finder including the range of the semi-transparent trimming mask. Therefore, the photometric light-receiving element 8 can receive a sufficient amount of light, and the luminance limit value does not decrease even for a low-luminance subject.
The brightness limit performance can be maintained.

Further, since the photometric value for the trimming photographing range can be accurately obtained from the luminance information obtained by measuring the spot light and the like existing in the trimming mask range, the exposure accuracy of the trimming photographing range does not decrease. . Further, since the high transmittance and the low transmittance of the trimming mask range in the trimming photographing mode can be set arbitrarily, the trimming mask has a high transmittance and a low transmittance which are easy to confirm in the viewfinder. You can set the value.

By setting the difference between the high transmittance and the low transmittance of the trimming mask to be small, it is also possible to suppress the discomfort of observing the subject in the viewfinder due to the repetition of the high transmittance and the low transmittance. it can.

In this embodiment, the transmittance of the trimming mask of the LCD panel is changed to be semi-transparent by changing the density of the dot pattern. However, the transmittance of the trimming mask is changed by diffusion. It may be translucent.

FIGS. 9, 10, 11, 12, and 13
Is a semi-transparent means for switching a trimming mask of an LCD panel at the time of trimming photographing. (A), (B), and (C) in FIGS. 9 to 13 show the high transmittance of the trimming mask of the LCD panel 4 during the normal shooting mode and the full transmission state of the LCD panel 4 during the trimming shooting mode, respectively. 2 shows a low transmittance state of the trimming mask in the state, the trimming photographing state mode.

FIG. 9 shows that the trimming mask is in the high transmittance state 31 shown in FIG.
In the low transmittance state 32 shown in FIG. 9C, the boundary 30 of the trimming photographing range of the LCD panel 4 is displayed. The borderline 30 indicates that the trimming mask has a transmittance close to the trimming photographing range. However, there is an effect that the boundary line 30 can be clearly recognized, and the trimming photographing range can be confirmed clearly.

FIG. 10 shows the LCD panel 4 displaying only the boundary 30 of the trimming photographing range when the trimming mask is in the high transmittance state shown in FIG. 10B in the trimming photographing mode. In the low transmittance state 33 shown in FIG. 10 (C), the transmittance can be set higher than in the other examples of the present embodiment. The performance of the limit can be raised. In the low transmittance state, the boundary of the trimming photographing range does not have to be displayed. In the trimming photographing mode, the trimming mask alternately switches between the high transmittance state and the low transmittance state and periodically appears on the finder, so that the photographer can clearly recognize the trimming photographing range.

FIG. 11 shows a state in which a semi-transparent mask plate is inserted in a range corresponding to the trimming mask in the trimming photographing mode. In the high transmittance state 34 shown in FIG. It is assumed that the rate state is 34. FIG.
In the low transmittance state 35 shown in (C), in addition to the mask plate, the LCD panel 4 is driven so that the trimming mask is in a semi-transmissive state, so that the transmittance is lower than that in the high transmittance state 34. It was done. Since a material such as an ND filter having a uniform transmittance can be used for the mask plate, there is an advantage that the subject in the viewfinder can be easily seen while recognizing the trimming photographing range.

FIG. 12 shows that the transmittance of the above-mentioned trimming mask is trimmed in the high transmittance state 36 shown in FIG. 12B and the low transmittance state 37 shown in FIG. In the vicinity of the boundary, and gradually increase the transmittance as the distance from the boundary increases.The finder range corresponding to the trimming mask near the boundary makes it difficult to see the subject image. The object images in the range are concentrated and made easy to see.

FIG. 13 is a view opposite to the example shown in FIG. 12, and shows a high transmittance state 38 shown in FIG. 13B and a low transmittance state shown in FIG. 39, the transmittance of the trimming mask is increased in the vicinity of the boundary of the trimming photographing range which is useful for framing of the trimming photographing, and the transmittance is gradually reduced in a portion away from the boundary which is not very useful. When the field of view of the trimming shooting is determined, the subject image around the trimming shooting range is made easier to see, and the framing of the trimming shooting is made easier.

FIGS. 14 and 15 show translucent means for switching the finder between normal photographing and trimming photographing in the photometric device according to the third embodiment of the present invention. FIG.
(A), (B) and (C) respectively show the high transmittance of the translucent means in the normal photographing mode and the translucent means in the trimming photographing mode in the first embodiment. And a state corresponding to the low transmittance state of the semi-transparent state in the trimming shooting mode. FIG. 15 is a sectional view taken along the line EE 'of the translucent means shown in FIG.

The trimming member 10 shown in FIG. 15 is disposed directly above the focusing screen 3 shown in FIG. 1 and in the range of the trimming mask. An LCD panel 44 is provided directly above the trimming member 10.

The trimming member 10 has a slightly lower transmittance than the focusing screen 3.
In the third embodiment, a thin plate of an ND filter is used for the trimming member 10. As the trimming member 10, a colored member may be used in addition to the ND filter, and the trimming member 10 may have a transmittance reduced by a dot pattern having an uneven transmittance. Further, the trimming member may not be provided as a single member but may be integrally provided on the focusing screen 3 or the light transmitting surface of the LCD panel 44 by printing or coloring. The arrangement position of the trimming member 10 is determined by the focusing screen 3 on which a subject image is formed by a photographing lens (not shown).
Should be near. The LCD panel 44 can switch and control the trimming mask range between two states, a transparent state and a state in which the transmittance is reduced.

The operation of the translucent means having such a configuration will be described. FIG. 14A shows a state of the translucent means in the normal photographing mode. In the normal photographing mode, the trimming means 10 has a state in which the transmittance of the trimming mask range is smaller than that of the trimming range. Therefore, in the normal shooting mode, the trimming range in the trimming shooting mode can be confirmed. However, the transmittance of the trimming means 10 is set to a value which does not hinder the observation of the subject image in the field of view of the entire viewfinder in the normal photographing mode. For example, when the trimming means 10 has the characteristics of an ND filter, -0.3 to -0.6 EV (81
Experiments have confirmed that a transmittance of about 66%) is effective. Therefore, in the normal shooting mode, framing of the entire viewfinder can be sufficiently performed, and framing in the trimming shooting mode can be performed at the same time. Therefore,
The user can easily select which of the normal shooting mode and the trimming shooting mode is more appropriate while directly observing which mode is better.

FIGS. 14B and 14C show the translucent means in the respective trimming photographing modes. In the high transmittance state shown in FIG. 14B, since the LCD panel 44 is not driven and the trimming mask is in the transparent state, the translucent means is the same as in the normal photographing mode shown in FIG. 14A. It is in the state of. In the low transmittance state shown in FIG. 14C, the LCD panel 44 is driven and the trimming mask is set in a semi-transmissive state by a dot pattern. It is in the rate state. In the trimming photographing mode, the high transmission state and the low transmission state are alternately switched and repeated. By calculating the photometric value obtained by photometrically measuring the entire viewfinder in the high transmittance state and the low transmittance state, the appropriate photometric data in the trimming range in the trimming photographing mode is calculated as in the first embodiment. Is obtained.

Next, the operation of a camera having a circuit configuration using such a semi-transparent means will be described with reference to the flowchart of FIG. 16 according to the block diagram of the circuit configuration shown in FIG. This flowchart is a subroutine in photometry. The sequence starts, and in step S31, it is determined whether or not the camera is in a trimming shooting mode.
The process proceeds to step S44, but proceeds to step S32 if the mode is the trimming shooting mode. Switching of the trimming photographing mode is performed by the trimming switching control circuit 17 by turning on the switch 18 (see FIG. 5).

When the mode is switched to the trimming photographing mode,
In step S32, the trimming mask is turned off without driving the LCD panel 44, and the trimming mask range of the translucent means is set to a high transmittance state. In this high transmittance state, in step S33, the fourth photometry (D
Perform 4). The photometric data D4 obtained by the photometry is stored in the memory of the CPU 11 in step S34.

In step S35, the LCD panel 4
4 to turn on the trimming mask to switch the trimming mask range of the semi-transmissive means to a low transmittance state. In the low transmittance state, a fifth photometry (D5) is performed in step S36. Photometric data D obtained by the photometry
5 is stored in the memory of the CPU 11 in step S37. In step S38, calculation is performed using the photometric data D4 in the high transmittance state in the trimming mask range and the photometric data D5 in the low transmittance state in the trimming mask range stored in the memory of the CPU 11. The Av apex value and the Tv apex value respectively corresponding to the aperture setting value and the shutter speed obtained by
In the memory.

In step S39, if the switch 16 (see FIG. 5) for starting the exposure sequence is not turned on for a predetermined time, the process returns to step S32, and the loop of steps S32 to S39 is repeated until the switch 16 is turned on. Is repeated. When the switch 16 is turned on and the exposure sequence is permitted, the process proceeds to step S40, and the exposure operation is performed in steps S40 to S42. That is, the mirror / shutter / aperture drive circuit 22 raises the movable reflection mirror 2 in step S40, sets the aperture in step S41, and opens and closes the shutter in step S42 (step S42). Is performed, and the exposure control circuit 2 in the trimming photographing mode is set based on the Av apex value and the Tv apex value.
1, an appropriate exposure operation is performed. When the exposure operation is completed, the aperture is returned to the open state in step S43, the movable reflection mirror is lowered to a predetermined position, and the exposure sequence in the trimming photographing mode ends.

Returning to step S31, if the mode is not the trimming photographing mode, that is, if the mode is switched to the normal photographing mode, the trimming mask is turned off without driving the LCD panel 44 in step S44, and the high transmission The state is the same as the rate state. In this state, in step S45, photometry (D
Perform 6). In step S46, an Av apex value corresponding to the aperture setting value and the shutter speed, respectively, calculated by using the photometric data D6 obtained by the photometry,
The Tv apex value is stored in the memory of the CPU 11.

In step S47, if the switch 16 (see FIG. 5) for starting the exposure sequence is not turned on for a predetermined period of time, the process returns to step S45, and until the switch 16 is turned on, in steps S45 to S47. , Photometry and photometry calculation are repeated. When the switch 16 is turned on and the exposure sequence is permitted, step S4
The exposure operation is performed in Steps S48 to S50. That is, the mirror / shutter / aperture drive circuit 22 raises the movable reflection mirror 2 in step S48, then sets the aperture in step S49, and opens and closes the shutter (step S50) in step S50. Then, based on the Av apex value and the Tv apex value stored in the memory of the CPU 11, an appropriate exposure operation is performed by the exposure control circuit 21 in the normal shooting mode. When the exposure operation is completed, in step S51, the aperture is returned to the open state, the movable reflecting mirror is lowered to a predetermined position, and the exposure sequence in the normal shooting mode ends.

In each of the above embodiments, an example has been described in which trimming photographing is performed in a panoramic size. However, it is needless to say that the present invention can be applied to a case where trimming is performed in each of the vertical and horizontal directions.

[0050]

As described above, according to the present invention, in the trimming shooting mode, not only the trimming shooting range but also the entire range of the finder including the range other than the trimming range having an arbitrary transmittance. Photometry is performed,
By obtaining a sufficient photometric light amount, the luminance limit performance can be maintained without lowering the luminance limit value for a low-luminance subject.

By calculating the photometric value of the subject luminance, an optimal photometric value only for the photographing range can be obtained.
An appropriate exposure at the time of trimming shooting can be obtained without being affected by the subject brightness in the trimming shooting range.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an optical system in a single-lens reflex camera capable of switching between a normal photographing mode and a trimming photographing mode according to a first embodiment of the present invention.

FIG. 2 is a front view showing the LCD panel in a high transmittance state and a low transmittance state during normal shooting and trimming shooting in the first embodiment, respectively.

FIG. 3 is a front view showing a subject image in a finder and a visual field thereof in a normal photographing mode of the first embodiment.

FIG. 4 is a front view of a subject image in a finder and a finder field showing a high transmittance state and a low transmittance state in the trimming photographing mode of the first embodiment.

FIG. 5 is a schematic block diagram showing a circuit configuration of the camera of the first embodiment.

FIG. 6 is a front view showing a high transmittance state and a low transmittance state of the LDC panel for explaining a method of calculating photometric data of a trimming photographing range in the first embodiment.

FIG. 7 is a diagram showing a method for calculating photometric data from the transmittance state shown in FIG. 6;

FIG. 8 is a flowchart showing an exposure sequence including photometry of a camera in the first embodiment.

FIG. 9 is a front view of an LCD panel in a high transmittance state and a low transmittance state in which a boundary line of a trimming shooting range is displayed during normal shooting and during trimming shooting in the photometric device of the second embodiment of the present invention.

FIG. 10 shows the LCD panels of the photometric device of the second embodiment in a normal transmittance state, in a high transmittance state only at the boundary of a trimming range in trimming shooting, and in a low transmittance state in trimming shooting, respectively. FIG.

FIG. 11 is a front view showing an LCD panel in a high transmittance state and a low transmittance state using a mask plate during normal shooting and trimming shooting in the photometric device of the second embodiment, respectively.

FIG. 12 is a front view showing the LCD panels in a high transmittance state and a low transmittance state in which the transmittance near the boundary of the trimming range is reduced during normal shooting and trimming shooting in the photometric device of the second embodiment, respectively. FIG.

FIG. 13 is a front view showing the finder visual field in the high transmittance state and the low transmittance state in which the transmittance near the boundary of the trimming range is increased during normal shooting and trimming shooting in the photometric device of the second embodiment, respectively. FIG.

FIG. 14 is a front view showing an LCD panel in a high transmittance state and a low transmittance state during normal shooting using the translucent means in the photometric device of the third embodiment of the present invention and during trimming shooting, respectively.

FIG. 15 is a sectional view of the translucent means of FIG. 14 taken along line EE ′.

FIG. 16 is a flowchart showing an exposure sequence including photometry of a camera in the third embodiment.

[Explanation of symbols]

4 LCD panel (finder state setting means) 8 Photometric light receiving element (photometric means) 11 CPU (storage means, photometric value calculating means)

Continuation of the front page (56) References JP-A-58-136020 (JP, A) JP-A-62-50748 (JP, A) JP-A-5-107598 (JP, A) JP-A-5-323477 (JP) , A) Japanese Utility Model 5-21243 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03B ^7/ 00-7/28 G03B 13/00-13/28 G03B 17/18 -17/20

Claims (2)

(57) [Claims] 1. Viewfinder field of view in normal shooting mode
And the viewfinder field of view in the trimming shooting mode.
In the photometric device of an observable camera, when the trimming photographing mode is set, the transmittance of the viewfinder field other than the viewfinder field corresponding to the screen area used for printing is determined by the first transmittance state and the second transmittance state. of
Viewfinder state setting means that can be set to one of the transmittance states ; light metering means arranged in the viewfinder optical path to measure the amount of light transmitted through the viewfinder field; and the light metering means in the case of the trimming shooting mode By
And the finder state setting means changes the
The finder field including a field portion in a first transmittance state.
And the above finder status setting
Field of view in said second transmittance state modified by means
Both of the photometric data obtained by photometric
Photometric data, the first transmittance state, and the second transmittance state.
Based on the ratio of the transmittance in the excess state,
A photometric value calculating means for calculating a photometric value corresponding to a finder field of view corresponding to a screen area to be displayed. 2. Viewfinder field of view in normal photographing mode
And the viewfinder field of view in the trimming shooting mode.
When the photometry device of an observable camera is set to the trimming shooting mode,
Other than the viewfinder field of view corresponding to the screen area used
Viewfinder that can change the transmittance of the viewfinder
State setting means , disposed in the finder optical path, and transmitting through the finder field of view.
Light measuring means for measuring the amount of light to be emitted, and the light measuring means in the trimming shooting mode.
Change of the transmittance by the finder state setting means.
The viewfinder view including the viewportion before being changed
The metering data obtained by metering and the finder status setting
The finder including the field of view modified by a step
The photometric data of both the photometric data obtained by
Based on the transmittance ratio before and after the transmittance change,
Viewfinder view corresponding to the screen area used for printing
A photometric value calculating means for calculating a photometric value corresponding to a field .