JPH0664290B2 - Camera with multiple shooting modes - Google Patents

Description

The present invention relates to a camera capable of trimming photographing.

[Conventional technology]

When taking a picture, it is important to decide the composition.To do this, change the distance to the subject, set the composition at the time of shooting using an interchangeable lens or zoom lens, and check the film after shooting. There is a method of trimming and burning the screen portion.

One of the latter trimming methods is to equip the camera with a finder optical system that can change the size of the field of view, select a screen range for shooting with this finder optical system, and perform trimming in conjunction with the finder optical system. Information is recorded on the film, and when printing, a part of the shooting screen is printed at a different enlargement magnification based on this trimming information, and the focal length is longer than the focal length of the lens attached to the camera. A camera capable of obtaining a print as if taken with a telephoto lens has been proposed (see Japanese Patent Laid-Open No. 54-26721).

[Problems to be Solved by the Invention] By the way, the same subject is photographed in such a trimming mode and a photograph taken by a lens having a focal length equal to the focal length set in a pseudo manner by the trimming mode. Comparing with and, you can see that the photo taken in trimming mode has a deeper depth of field.

Now, assuming that the depth of field a ₁ of a lens with a focal length f = f ₁ is the distance U to the subject (where U >> f), the lens F number is F, and the diameter of the permissible circle of confusion is δ, Is represented.

Similarly, the depth of field a ₂ of the focal length f = f ₂ lenses, Is represented.

On the other hand, when trimming a photograph taken with a lens with a focal length f = f ₁ so as to correspond to a photograph taken with a lens with a focal length f = f ₂ , the permissible circle of confusion diameter corresponding to f = f ₂ is δ.
Therefore, the permissible circle of confusion diameter at f = f ₁ is δ, f ₁ / f ₂ .

The depth of field a _{3 at} this time is Is represented.

Therefore, the depth of field a ₃ and the focal length f = f ₂ when the photograph taken by the lens with the focal length f = f ₁ is trimmed
Comparing the depth of field a _{2 of} the picture taken with the lens of In the case of trimming, the depth of field becomes f ₂ / f ₁ times deeper. Since this magnification corresponds to the trimming ratio, the depth of field becomes deeper by the trimming ratio.

As described above, the trimmed photo has a deep depth of field, so the person and the background can be clearly seen like a snap shot while traveling, and it is good as a recorded photograph, but like a boat rate photograph, When a focused and blurred background is desired, cropped photos are less than satisfactory.

[Means for solving problems]

An object of the present invention is to solve the above-mentioned problems, and when the first shooting mode is selected, the aperture is controlled to the open side, which enables photography with a shallow depth of field. Is.

Here, a brief description of the aperture and the depth of field,
Now, the focal length f = photos taken by f ₁ of the lens trimmed to correspond to photographs taken at f = f ₂ of the lens, the same depth of field as the photos taken by f = f ₂ of the lens In order to obtain, from the formula (2), the formula (3), Therefore, Therefore, for example, to obtain the same depth of field by performing trimming shooting using a shooting lens with a focal length of 1/2,
The F number should be set to the open side by 1/2.

In view of this, the camera of the present invention has a wider range compared to the first photographing mode by changing the screen range used at the time of printing on the film between the first photographing mode as the photographing mode and the first photographing mode. In a camera provided with a plurality of shooting modes including a second shooting mode capable of obtaining a print of the scene, a shooting mode selecting means for selecting one of the shooting modes and a brightness of the scene are measured. The exposure value is calculated based on the photometric means, the field brightness measured by the photometric means, and the shooting mode selected by the shooting mode selection means, and the first shooting mode is selected by the shooting mode selection means. In this case, the exposure calculation control means for setting the aperture to the open side is provided as compared with the case where the second photographing mode is selected.

[Operation] When the first shooting mode is selected as the shooting mode and input to the exposure calculation control means, the exposure value calculated based on the field brightness and the selected shooting mode is used as the second shooting mode. Exposure control is performed by correcting the aperture value to the open side rather than the aperture value in. As a result, when the first shooting mode is selected, the aperture is set to the open side as compared with the case of the second shooting mode, so that it is possible to shoot a photograph with a shallow depth of field.

〔Example〕

 Next, an example of this camera will be described.

FIG. 1 shows the appearance of an embodiment of the camera of the present invention. Reference numeral 1 is a camera body, 2 is a photographing lens, 3 is a photographing mode selection button, and a normal photographing mode and a trimming mode alternate each time the button is pressed. Switch to. When the trimming mode is selected by the trimming mode switching button 4, the switching between the trimming A mode with a shallow depth of field and the trimming B mode with a deep depth of field is performed. 5 is a liquid crystal display panel for displaying the photographing mode, 6 is a flash light emitter, 7
Is a shutter button, 8 and 9 are side windows of the automatic focus detection unit,
10 is a finder window, and 11 is a finder window.

FIG. 2 shows a liquid crystal display panel for displaying the photographing mode.
In FIG. 10A, 12 is a trimming A mode, 13 is a trimming B mode, and 14 is a normal mode display unit. Further, numeral 15 is a trimming mode display portion which is displayed in both the A mode and the B mode.

FIG. 2B shows the display state of the liquid crystal display panel when the normal mode is selected, and only the normal mode display section 14 is lit.

FIG. 2 (c) shows the display state of the liquid crystal display panel when the trimming mode is selected.
2. Trimming B mode display section 13 and trimming mode display section 15 light up. When the trimming A mode is selected, the A mode display section 12 is dark and the B mode display section is dark.
When the trimming B mode is selected, the A mode display portion 12 is light and the B mode display portion 13 is dark.

Next, the camera system will be described. FIG. 3 is a circuit diagram of the camera system. In the figure, the CPU is a microprocessor, which normally stops the clock, minimizes power consumption, is in a waiting state (standby state), and starts operating when an interrupt signal is input to the interrupt terminal INT.

S ₁ is a photometric switch, S ₂ is a release switch, and by pressing the shutter button 7 respectively, S ₁ at the first stage
However, S ₂ turns on in the second stage. S ₃ is turned ON and start open shutter trigger Sui Tutsi to be OFF on the film take complete, S ₄ is OFF at the end of the exposure control operation, hoisting completion switch which becomes ON on the film take complete, S ₅ is It operates by pressing the shooting mode selection button 3 with the switch for selecting the normal mode and the trimming mode. S ₆ is trimming A
It operates by pressing the trimming mode switching button 4 with the switch for switching between the mode and the trimming B mode. The switches S ₁ , S ₂ , S ₅ , and S ₆ are input to the interrupt terminal INT via the AND gates AN ₁ and AN ₂ , and the switch S ₄ is an OR gate OR.
When the switch S ₄ is off, that is, during the release operation, the input signals from the photometric switch S ₁ and the release switch S ₂ are not input to the interrupt terminal.

The LM measures the brightness of the subject and A / D converts the brightness information to the CPU.
Measuring unit for the delivery to the input port I _B, AF measures the distance to the object, an automatic focus adjusting unit that controls the movement of the lens, these metering portion LM and the automatic focus adjusting portion AF power of the CPU It is supplied from a power transistor TR controlled by a signal from the output port O ₁ .

The photometry unit LM and the automatic focus adjustment unit start their operations when the power is supplied, and the result is sent to the input ports I _B and I _D of the CPU, and the automatic focus adjustment unit AF further outputs the output port O _{2 of the} CPU.
The amount of movement of the lens is monitored by receiving the release signal from the
Demagnetize and stop the lens. Then, the focus adjustment is completed to the input port I _{6 of the} CPU, and a signal notifying that the lens is stopped is sent.

MD is Release Magnet RMG and Shutter Magnet S
In the MG control unit, the magnets are operated by the signals from the CPU output ports O ₃ and O ₄ . The release magnet RMG starts the release operation when it is on for a certain period of time, and when the shutter magnet is on, it opens the shutter.
Mechanically configured to start closing when turned off.

The FL is composed of a control unit and a light emitting unit of the flash light emitter,
The signal from the output port O _{5 of the} CPU controls the charging, and the signal from the output port O ₆ controls the light emission.

LE is a light emitting element that copies trimming information to the film when shooting in trimming mode.
Operated by the signal from ₈ . BA is a drive buffer.

DX is a film sensitivity information reading unit on the film cartridge, and the read sensitivity information is input from the input port I _{C of the} CPU.

_{DE, DR 1, DR 2,} LD in components for displaying a photographing mode on the liquid crystal display panel, DE decode portion of the display signal from the output port O _D of CPU, DR _1, DR ₂ is a display device The driving driver and LD are liquid crystal display elements. Further, the signal from the output port O _{7 of the} CPU is a signal for controlling the shading of the display element, and is the mode A and the mode B in the trimming mode.
The lightness is controlled by changing the drive voltage of the display element in accordance with.

In the figure, BAT is a power supply battery, C and D are respectively
A capacitor and a diode for stabilizing the supplied power.

Next, signal processing relating to photographing performed in the CPU will be described with reference to FIGS. 4, 5, and 6.

Figure 4 is shows a flow chart of the interrupt processing, an interrupt signal is input to the interrupt terminal INT, first, it determines whether the signal from any switch _{S 1, S 2, S 5} , S 6 for generating an interrupt To do.

First, the shooting mode selection switch S ₅ is checked, and if it is ON, it is checked whether the shooting mode previously set is the normal shooting mode or the trimming mode. If the previous mode is the normal mode, the trimming mode is set. If the previous mode is the trimming mode, the normal mode is set. By this processing, each time the photographing mode selection switch S ₅ is turned on, the two modes can be switched alternately.

When the trimming mode is set, the trimming A mode with a shallow depth of field is first set, and the output signal of the gradation control port O ₇ of the display element of the photographing mode display section is set to "L". As a result, the display state of the photographing mode display section is as shown in FIG. 2 (c), the A mode display section 12 is dark and the B mode display section 13 is light.

When the normal mode is set, the display state of the photographing mode display section is as shown in FIG. 2 (b).

If shooting mode selection switch S ₅ is OFF, it examines the last shooting mode, if the trimming mode, examine the trimming A mode, B-mode changeover switch S _6. S ₆ is ON
If so, it is checked whether the previously set mode is the A mode or the B mode, and if the mode is the A mode, the mode is set to the B mode, and if the mode is the B mode, the mode is set to the A mode. Then, the output signal of the output port O ₇ of the CPU is set to “L” in the A mode and set to “H” in the B mode, and the display of the photographing mode display section is performed.

As described above, in any case, after the shooting mode is displayed, the standby state is entered.

When the previous shooting mode was the normal mode, and when the trimming mode mode A / mode B switch S ₆
If it is OFF, check the photometric switch S ₁ , and if S ₁ is OFF, at this time, for example, an interrupt was caused by noise, or the trimming A mode / B mode switching switch S ₆ was turned on in the normal mode. It is an interrupt by and shifts to the standby state without performing any processing.

If the photometry switch S ₁ is ON, the boosting operation for charging the flash light emitter is stopped to eliminate the influence on the photometry and the focal length operation due to the fluctuation of the power supply voltage, and the power supply transistor TR is turned on to perform the photometry. Power is supplied to the unit LM and the automatic focus adjustment unit AF, and photometry and distance measurement are started. Wait for a fixed time until metering and distance measurement are completed, and then input the metering value and distance measurement value to the CPU.

Next, the reading section DX is operated to read the film sensitivity information recorded on the film cartridge, and it is input to the CPU to prepare for release.

Check the release switch S ₂ and if it is ON, move to the release routine. If S ₂ is OFF, check photometric switch S ₁
If N, return to check S ₂ again. If S ₁ is OFF, the power supply transistor TR is turned OFF, the photometry unit and the distance measurement unit are made inoperative, the boosting for charging the flash light emitter is started, and the standby state is returned.

Next, the release routine will be described with reference to the flow chart of FIG.

First, the release magnet is turned on for a certain time by the signal from the output port O _{3 of} the CPU, and the release signal is sent to the automatic focusing section AF by the signal from the output port O _{2 of the} CPU. As a result, the release operation is started, the release moves, the lens is stopped when the focus state is reached, and the result is sent to the input port I _{6 of the} CPU.

On the other hand, the CPU basically performs the exposure calculation that determines the exposure value from the photometric value and the film sensitivity information, and calculates the shutter release time and the flash emission timing. This will be described in detail later.

When exposure calculation is finished, examine the shooting mode, when the trimming mode for imprint the crop marks on the film surface, sends a signal transcribing from the output port O ₈ of CPU,
The light emitting element LE is turned on. The lighting time is controlled by the film sensitivity information previously input to the CPU. This processing is omitted in the normal mode.

Next, the completion of the focus adjustment is checked by the signal of the input port I ₆ of the CPU, and when it is completed and the lens is stopped, the magnet control unit MD is operated to excite the shutter magnet SMG to excite the shutter. Start the opening operation. When the shutter starts to open and the exposure of the film starts, the trigger switch S ₃ turns ON. Torigasuitsuchi S ₃ waits to become ON when OFF, the when turned ON counts until it coincides with the exposure time calculated above.

Further, in the case of flash photography, this is because the flash photography flag is set to 1 when the flash light is determined to be necessary when the exposure calculation is first performed. That is, in the case of flash photography, the light emission timing at which the shutter is opened by a predetermined opening is determined, and a light emission command signal is sent from the output port O _{6 of the} CPU to the flash light emitter control unit FL to cause the flash to emit light.

When the calculated exposure time is reached in both natural light shooting and flash light shooting, it is judged that the exposure has ended and the shutter magnet SMG is demagnetized and the shutter is closed.

On the other hand, when the exposure amount has been counted before the light emission timing is reached, the shutter magnet SMG is demagnetized and the flash light is emitted.

When the exposure is completed, the power supply transistor TR is turned off to stop the photometry and distance measurement operations, start boosting the flash light emitter for charging, reset the flash photography flag and shift to the standby state.

Next, the exposure calculation routine will be described with reference to the flow chart of FIG.

First, the proper exposure value Ev is calculated from the subject brightness measured by the photometry unit LM and the film sensitivity from the film sensitivity information reading unit DX.
To calculate.

Next, it is checked whether or not the shooting mode is the trimming mode and the A mode having a shallow depth of field is selected. If the A mode is selected, 2 is subtracted from the previously calculated exposure value Ev, and this is used for the exposure control. Ev value. It is checked whether the Ev value is 8 or smaller than 8. If the Ev value is smaller than 8, the flash photographing flag is set to 1 for flash photographing. Then, enter the low brightness limit value 8 in Ev, calculate the count value of the flash emission timing from the distance measurement value and the film sensitivity,
Further, the count value of the exposure time is calculated from the Ev value, and the exposure calculation is finished.

When the Ev value is greater than 8, it is determined whether it is greater than 18, and when it is 18 or more, 18 is entered as the high brightness limit value, and the count value of the exposure time is calculated based on this, and the exposure calculation is performed. To finish. If the Ev value is greater than 8 and less than 18, the Ev
The count value of the exposure time is calculated by the value, and the exposure calculation is ended.

Fig. 7 shows exposure value Ev and aperture value in case of program shutter
Relationship between Av and shutter speed value Tv, and exposure error ΔEv
It is the figure which showed the relationship of.

In the drawing, Ev is plotted on the horizontal axis and Av and Tv are plotted on the vertical axis. The solid line shows the case where the shooting mode is normal or the trimming B mode, and the dotted line shows the case where the trimming A mode is used.

Now, assuming that Ev = 12, Av = 5 and Tv = 7 in the normal mode and trimming B mode, and Av = 4 and Tv = 6 in the trimming A mode, and set 2Ev lower.

Further, in the normal mode and the trimming B mode, the flash photography is performed when the Ev value is 8 or less, and in the trimming A mode, the Ev value is 10 or less. On the other hand, when the Ev value is 18 or more, the high brightness is limited in the normal mode and the trimming A mode, and both Av and Tv are fixed to the values calculated by Ev = 18.

The embodiment of the present invention has been described above. In the trimming A mode, the aperture is opened by one step (1 / ▲ √ ▼ times), so that the focal length ratio f = f ₁ = f ₂ / ▲ √ ▼ 2. When using a lens, the same depth of field as that taken with a lens with f = f ₂ is obtained. That is, the focal length of the lens attached to this camera is set to 35 mm, and a photograph of the film photographed in trimming A mode with this lens is printed so as to correspond to that photographed with a lens with a focal length of 50 mm, and the actual focus Shooting with a 50mm lens at a distance and comparing it to a printed photograph gives a print with the same depth of field.

Further, in this embodiment, the exposure control uses a program shutter, so the Ev value is corrected to a low value in order to control the aperture to the open side, resulting in overexposure, but a trapezoidal shutter is used for the shutter. It is also possible to give an appropriate exposure by controlling the shutter speed to correct the shutter speed to a high speed side. It can also be applied to a camera such as a single-lens reflex camera that controls the aperture and the shutter separately.

〔The invention's effect〕

As described above, according to the present invention, when a desired shooting mode is selected and set in the camera, it is possible to shoot a photograph having the optimum depth of field in the selected and set shooting mode. . That is, if this is explained in the embodiment of the present invention, simply by operating the photographing mode selection button,
You can enjoy two kinds of photography, one is normal photography and the other is a photograph with shallow depth of field similar to that taken with a telephoto lens.

[Brief description of drawings]

FIG. 1 is a perspective view of a camera according to an embodiment of the present invention, FIG. 2 is a front view showing a display state of a photographing mode displayed on a liquid crystal display plate, FIG. 3 is a circuit diagram of a camera system, and FIGS. 6 is a flow chart of signal processing in the CPU, FIG. 4 is a flow chart of an interrupt processing routine, FIG. 5 is a flow chart of a release routine, FIG. 6 is a flow chart of an exposure calculation routine, and FIG. FIG. 4 is a diagram showing a relationship between an exposure value and an aperture / shutter speed. 1: camera body, 2: shooting lens, 3: shooting mode selection button, 4: trimming A mode, B mode switching button, 5: liquid crystal display board, 6: flash light emitter, 7: shutter button.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Manabu Inoue 2-30 Azuchi-cho, Higashi-ku, Osaka, Osaka Prefecture Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Kudo ▲ Yoshinobu Shin, Azuchi, Higashi-ku, Osaka 2-30, Machi Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Hiroshi Ueda 2-30, Azuchi-cho, Higashi-ku, Osaka-shi, Osaka Osaka Minami Camera Building Osaka

Claims (1)

[Claims] 1. A first photographing mode as a photographing mode, and a screen range used for printing on the film is changed between the first photographing mode and the first photographing mode, so that a wider field range than that of the first photographing mode is obtained. In a camera having a plurality of photographing modes including a second photographing mode capable of obtaining a print, a photographing mode selecting means for selecting one of the photographing modes, and a photometric means for measuring the brightness of the field. And an exposure value is calculated on the basis of the field brightness measured by the photometric means and the photographing mode selected by the photographing mode selecting means, and the first photographing mode is selected by the photographing mode selecting means. Is provided with exposure calculation control means for setting the aperture to the open side as compared to when the second shooting mode is selected. La.