JP2687246B2 - Imaging condition determination device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a photographing condition determining apparatus for determining photographing conditions.

(Background of the Invention) Conventionally, as exposure control of a camera, a so-called program automatic exposure (automatic exposure) that automatically selects an optimal aperture and shutter time according to brightness, film sensitivity used, and use condition of strobe ( AE) is known.

Further, in recent years, various image blur preventing devices have been proposed for the purpose of preventing camera shake. The function of the image blur prevention device means that a photograph without an image blur can be taken even if the exposure is performed at a shutter speed slower than the conventional one.

However, in the above conventional example, the program exposure is performed as usual even when the image blur prevention device is functioning, so the aperture value tends to be closer to the open side during natural light photography, and the photograph with a shallow depth of field remains. In addition, the proper exposure range of the background light remains narrow during the stroboscopic light photography, and the function of the image blur prevention device is not fully utilized.

 The above will be described in detail.

The program exposure of the camera automatically determines the aperture value and shutter speed according to the brightness based on the program diagram. There are various methods of constructing this program diagram, but the basic idea is to set the aperture value to the small aperture side when it is bright.
When it is dark, the shutter is controlled to the open side so that the shutter speed with the least camera shake is selected. The shutter speed that tends to cause camera shake is determined by the focal length of the lens, and in general,
It is said that 1 / f is the standard for the second when it is hard to shake.
Therefore, in the current camera, the focal length information of the lens is read, and the diagram is changed according to the focal length of the lens as shown in the program diagram of FIG. In FIG. 8, PT is telephoto (for example, f = 135 mm or more), and PN is standard (f = 35 to 135).
mm) and PW are program diagrams for wide-angle (f = 35 mm or less) lenses.

For example, in the telephoto PT diagram, control is performed with the lens open FNO so that the earliest possible second is selected in darkness.
Seconds with increased brightness and less camera shake (in this case 1/250
(Seconds), the aperture value is controlled to a small aperture side when it becomes faster, and the depth of field is configured to gain. In this camera, 1/2000 second is the limit time that can be handled as a camera, so after 1/2000 second is reached, the diagram is vertical so that proper exposure can be guaranteed only by controlling the aperture value.

The diagram for standard PT and wide-angle PW has the same idea, but the diagram starts bending at the low speed side by considering that the seconds that are likely to cause camera shake are 1/4 second and 1/30 second, respectively. doing.

However, if the image blur prevention device functions, image blurring can be prevented even at a slow shutter speed, and even if the camera shake second is shifted to a slower speed than 1 / f, which is the standard for the conventional camera shake prevention second, Despite the fact that it does not cause any harm, it is not possible to make full use of the merit of preventing image blur because it is controlled by the conventional line diagram.

Also, the program for flash photography (F) is
It is usually like the FPN diagram in FIG. In this diagram, when it is bright (daylight sync state), the main subject is backlit, so the aperture value and shutter speed are selected so that the external light, that is, the background light, is in the proper exposure state. Properly expose with strobe light. When it is dark, the limit is set at the time when the effect of camera shake is small and flash photography is performed. Even in the dark, even if you intend to shoot a person in a night view because the limit is set in seconds, the night view, that is, the background is not exposed, and only the person who is the main subject is exposed by the strobe light and becomes a photograph of only the person. This is contrary to the photographer's intention.

Even when the image blur prevention device is driven during such stroboscopic light photography, the conventional control is performed, and the merit of the image blur prevention device does not appear.

(Object of the Invention) In view of the above-described circumstances, the present invention is to provide a photographing condition determining device that can determine a proper photographing condition in relation to an image blur suppression device.

(Characteristics of the Invention) In order to achieve the above object, the present invention suppresses image blur by an image blur detection unit and an image blur correction unit that corrects image blur in response to a detection output of the image blur detection unit. The image-shooting condition determining device includes a determining unit that determines whether or not the image-shake suppressing device performs predetermined image-shake suppressing, and a variable unit that changes both the shutter time and the aperture value according to the determination result of the determining unit. It is a thing.

(Embodiment of the Invention) FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

In FIG. 1, 11 is a microcomputer for controlling the entire sequence provided in the camera body, 12 is a switch (SW1) that is turned on by half-pressing the release button, and 13 is a release switch (ON that is turned on by fully pressing the release button. SW2). 1
Reference numeral 4 denotes a known flash circuit, which outputs a charge completion signal to the camera and starts and stops light emission in response to a command from the microcomputer 11. Reference numeral 15 denotes a shutter control circuit, which drives the shutter front curtain and the rear curtain according to a command from the microcomputer 11. Reference numeral 16 is a photometric circuit, which transmits subject brightness information as information for setting exposure conditions to the microcomputer 11, or measures the strobe light when shooting with flash light, and sends a flash light stop signal to the microcomputer 11 when a predetermined amount of light is reached. Tell.
Reference numeral 17 is a film sensitivity input section, which automatically reads the DX code of the film and transmits it to the microcomputer 11 (this may be manually input to the microcomputer 11 for film sensitivity). A display circuit 18 displays shooting information (aperture value, shutter speed value, etc.). Reference numeral 19 denotes a microcomputer in the lens, which performs lens sequence control. Reference numeral 20 is a switch for starting the image blur prevention device, 21 is a known diaphragm drive circuit, and 24 is a photographing lens (a part thereof). Reference numeral 22 is a drive circuit for driving the image blur prevention device, 9 is a lens, 7 is a variable resistor, and 6 is a motor, which constitute the image blur prevention device shown in FIG.

FIG. 2 is a block diagram showing the configuration of the image blur prevention device.

In FIG. 2, reference numeral 1 is an accelerometer, and the photographing lens 24
Is a sensor for detecting the image blurring state of the camera, and detects the tilt of the camera (not shown) with respect to the photographing optical axis as acceleration. The detected acceleration signal a is converted into a velocity signal by the first integrator 2 and further converted into a displacement signal P by the second integrator 3. 4 is an operational amplifier. Reference numeral 5 denotes an analog switch, which is turned on when a high level signal is input from the terminal P0 of the microcomputer 22 and turned off when a low level signal is input. Reference numeral 6 is a lens driving motor, 7 is a lens position detecting variable resistor, 8 is a lens support rod, and 9 is a lens that can be moved in the vertical direction to prevent image blur.

This image blur prevention device has a feedback loop configuration in which the operational amplifier 4 outputs the signal to the motor 6 so that the displacement signal P obtained by the integrator 3 matches the amount of lens displacement detected by the variable resistor 7. Has become.

The operation will be described below with reference to the flowcharts of FIGS.

First, the microcomputer 11 switches 12 (SW1) with # 1 in FIG.
Judges whether or not is ON, and if it is OFF, ends the operation immediately. If it is ON, the film sensitivity Sv is loaded from the film sensitivity input section 17 in # 2, the subject brightness Bv is loaded from the photometric circuit 16 in # 3, and # 4
Calculate the Ev value at. This is obtained by the sum of the film sensitivity Sv which is the apex value and the subject brightness Bv. Next, in # 5, transmission / reception with the lens is performed, and the open aperture value and ON / OFF information of the switch 20 (from IS (Image St
abilizer: Image blur prevention device) Described as SW information), and lens focal length f information is acquired. Flash circuit at # 6
If the charge completion state of 14 is judged, if it is not completed, the exposure condition setting by only natural light is set in # 7, and if the charge is completed, # 8.
The exposure conditions are set after taking the strobe light into consideration (details of # 7 and # 8 will be described later). Then, in # 9, the shutter speed, aperture value, charge completion information, etc. determined in # 7 or # 8 are displayed.

Next, at # 10, it is determined whether or not the release switch 13 (SW2) is turned on. If it is off, the process returns to # 1 and the sequence up to this point is repeated until the switch 12 (SW1) is turned off. On the other hand, if it is ON, the known exposure control is performed in # 11. First, the aperture value information determined in # 7 and # 8 is transmitted to the lens side microcomputer 19, and the microcomputer 19 is caused to perform control according to the aperture value via the aperture drive circuit 21. Next, the microcomputer 11 sends # 7, # 8 to the shutter control circuit 15.
The shutter front curtain based on the shutter time determined by
The shutter is controlled for the rear curtain. At this time, if the charging is completed, the flash circuit 14 is instructed to start the light emission after the front curtain travel is completed, the photometry circuit 16 measures the flash light, and if the predetermined light amount is reached, the light emission is stopped. The flash circuit 14 is instructed. After controlling these exposures,
Return to 1.

Next, a case where the # 7 “AE determination” routine is called in FIG. 3 will be described with reference to the flowchart in FIG.

First, in # 21, the ISSW information read in # 5 in FIG. 3 is judged. When the switch 20 in FIG. 1 is ON, the microcomputer 19 outputs a high level signal to the drive circuit 22 via the terminal P0 terminal. At this time, the analog switch 5 in the drive circuit 22 Turns on and the image blur prevention device operates. When the switch 20 is off, the analog switch is off and the image blur prevention device does not operate. Information of this switch 20, whether ISSW is ON or not
It is transmitted from 19 to the microcomputer 11 on the camera side.

As a result, if it is OFF, the focal length f of the lens obtained in # 5 is determined in # 22, and if it is wide-angle (abbreviated as W, for example, f = 35 mm or less), in # 23, the program chart 8 Select "PW" in the figure, and Ev calculated in Figure 3, # 4
The aperture value (Av) and shutter speed (TV) are determined based on the value. For example, when Ev = 11, F5.6 is selected as the aperture value and 1 / 60S is selected as the shutter speed.

If it is standard (abbreviated as N, for example, f = 35 to 135 mm) in # 22, "PN" in FIG. 8 is selected in # 24. At this time, Ev =
If 11 then F3.5 (between F4 and F2.8), 1/180 second (1/125 and 1/25
(Middle of 0 seconds) will be selected.

If it is telephoto (abbreviated as T, for example, f = 135 mm or more) in # 22, "PT" in FIG. 8 is selected in # 25. At this time, Ev =
If 11, F2, 1/500 seconds will be selected.

In this way, the exposure condition selected depends on the focal length f of the lens, and as explained in the background section of the invention, the faster the shutter speed is selected as the focal length f on the telephoto side becomes. become.

On the other hand, if ISSW information is ON in # 21, # 26
When the focal length f is determined, the process proceeds to # 23 when the wide angle W or the standard N is set, and the process proceeds to # 24 when the telephoto T is set. As a result, IS
When the SW information is ON, the program diagram of the wide-angle PW when the ISSW information is OFF is selected when the wide-angle or standard lens is used, and when the telephoto lens is used, the standard P when the ISSW information is OFF.
N program diagrams are selected.

After all, slower shutter speeds (3 stops in this case) are selected for standard and telephoto lenses, and for standard Ev = 11,
F3.5, 1/180 sec → F5.6, 1/60 sec, at telephoto, F2, 1/50 sec
Shifting from 0 seconds to F3.5 and 1/180 seconds, the aperture value will be further reduced, enabling photography with a deep depth of field.

Next, during flash light photography, that is, # 8 in FIG.
The case where the "FE decision" routine of is called
This will be described with reference to the flowchart in FIG.

If ISSW information is OFF at # 31 in Fig. 5, it is No. 9 at # 33.
Figure, select the FPN program diagram. At this time, Ev = 3
If so, F2, 1/60 second is selected.

On the other hand, if the ISSW information is ON in # 31, the focal length f of the lens is determined in # 32, and if the wide angle W or the standard N is selected, the FPNW in FIG. 9 is selected in # 34. To do. Therefore, at this time, if Ev = 3, F2 and 1/4 second will be selected.

If it is the telephoto T in # 32, the FPT in FIG. 9 is selected in # 35. Therefore, if Ev = 3 at this time, F2 and 1/30 second are selected.

In Fig. 9, depending on the focal length f, FPT is selected at the time of telephoto T and the limit is "1/30 sec."
The FPNW is selected for standard N and the limit is "1/4 second". The reason is that the ISSW information during natural light shooting in Fig. 8 coincides with the start time of the line bending when the diagram is ON. Even though this is an image blur prevention device, it is not possible to completely realize image blur prevention, and naturally there is a limit value, so a limit is set. Also, as it becomes more difficult to prevent camera shake toward the telephoto T side, the limit is set when the second is higher than the wide angle W or the standard N.

After all, when using the flash photography shown in Fig. 5, IS
Depending on whether the SW information is ON or OFF, that is, whether the anti-shake function is working, at telephoto T, Ev = 3, 1/60 second → 1/30
The shutter time becomes longer every second, and the amount of external light and background light taken in increases accordingly. Also, at wide-angle W and standard N, 1/60
From 1 second to 1/4 second, the amount of external light and background light taken in will increase compared to the time of telephoto T.

In this way, when the ISSW information is in the ON state, the shutter speed becomes longer, so the amount of external light taken in increases.
Even when shooting with flash, not only the main subject becomes appropriate, but also the outside light, that is, the area in which the background is captured, will increase.

FIG. 6 shows another embodiment of the "AE determination" subroutine of # 7 in FIG. 3 during natural light photography.

In FIG. 4, when the ISSW information is ON, OF
The program diagram for the F state is also used to select from these, but in this embodiment, the diagram for the ON state is prepared separately as shown by the dotted line in FIG.

First, in FIG. 6, if the ISSW information is OFF in # 41, the focal length f is determined in # 42 as in the flow of FIG.
At wide angle W, # 44 at # 44, PW at standard N #
PN is selected at 45, and PT is selected at # 46 at telephoto T.

On the other hand, if it is ON at # 41, the focal length f is determined at # 43. At wide angle W, PWS in FIG. 10 at # 47, at standard N, PNS at # 48, at telephoto T At # 49, PTS
Each will be selected.

As a result, when the ISSW information is in the ON state under the same condition (same Ev value) as in the OFF state, the one-step shutter time becomes longer and the one-step aperture value shifts to the smaller aperture side. For example, in PT and PTS, if Ev = 11, F
It will shift from 2, 1/500 seconds to F2.8, 1/250 seconds.

FIG. 7 shows another embodiment of the "FE determination" subroutine of # 8 in FIG. 3 at the time of flash light photography.

5 and 9 show the configuration when the ability of the image blur prevention device is limited, but FIGS. 7 and 11 show an embodiment when the ability of the image blur prevention device is perfect. .

In FIG. 7, when the ISSW information is OFF in # 51, # 52
The FPN of FIG. 11 similar to that of FIG. 5 is selected at and the Tv and AV values are determined based on the Ev value.

On the other hand, if the ISSW information is ON in # 51, the FPS diagram in FIG. 11 is selected in # 53. In this diagram, by losing the shutter speed limit, so-called perfect slow sync photography of a flash becomes possible. At this time, the outside light (background) is always appropriate, and even when photographing a person such as a night scene, both the person and the night scene are properly exposed, and a beautiful photograph can be taken.

According to the present embodiment, when the image blur prevention device is functioning, the exposure condition can be set to a slower shutter speed, so that it is possible to obtain a photograph with a deep depth of field during natural light photography. In addition, since the amount of external light (background light) taken in at the time of flash light photography increases, it becomes possible to widen the exposed areas of the main and sub subjects.

(Correspondence between Invention and Embodiment) In the illustrated embodiment, step 21 (FIG. 4), step 31 (FIG. 5), step 41 (FIG. 6), step 51
The part that executes (FIG. 7) is the determination means of the present invention, and steps 23 to 25 (FIG. 4), steps 33 to 35 (FIG. 5), steps 44 to 49 (FIG. 6), step 52, The parts that execute 53 (FIG. 7) correspond to the variable means of the present invention.

(Modification) In FIGS. 8 and 10, three kinds of programs of wide-angle W, standard N, and telephoto T were prepared.
The focal length f of the lens may be adjusted more finely.

Further, in FIG. 4 (FIG. 8), the program shift is performed at the standard N and the telephoto T when the ISSW information is ON, but the program shift can be permitted only at the telephoto T.

Further, in FIG. 9 and FIG. 11, it is possible to prepare a diagram that changes with the focal length f as shown in FIG. 8 as a diagram when the ISSW information is in the OFF state.

Further, in FIG. 9, the same line diagram (FPNW) is selected when the ISSW information is in the ON state, when the wide angle W and the standard N are set. However, even if each line diagram is prepared as shown in FIG. good. Also, in FIG. 11, the ISSW information is uniform regardless of the focal length f.
The FPS diagram was set when ON, but in combination with Fig. 9, it is possible to select the FPS diagram only within a predetermined focal length range, and the others are FPS.
You may make it become like PT and FPNW.

(Effects of the Invention) As described above, according to the present invention, it is possible to determine an appropriate shooting condition in relation to the image blur suppression device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing the structure of an image stabilizing device, FIG. 3 is a flow chart showing the same overall operation, and FIG. 5 is a flowchart showing an operation at the time of FE determination, FIG. 5 is a flowchart showing an operation at the time of AE determination in another embodiment of the present invention, and FIG. FIG. 8 is a flowchart showing the operation of FIG. 4, FIG. 4 is a program diagram selected at the time of AE determination operation, FIG. 9 is a program diagram selected at the time of FE determination operation of FIG. 5, and FIG. 10 is FIG. FIG. 11 is a program diagram selected during the AE determination operation, and FIG. 11 is a program diagram selected during the FE determination operation in FIG. 6 ... Motor, 7 ... Variable resistance, 9 ... Lens, 11 ...
Microcomputer, 14 ... Flash circuit, 15 ... Shutter control circuit, 19 ... Microcomputer, 20 ... Switch, 21 ... Aperture drive circuit, 22 ... Drive circuit, 23 ... Aperture.

Claims (1)

(57) [Claims] 1. An image blur suppression device that suppresses image blur by image blur detection means and image blur correction means that corrects image blur in response to a detection output of the image blur detection means performs predetermined image blur suppression. An image pickup condition determining apparatus, comprising: a determination unit that determines whether or not a shutter speed and an aperture value are changed according to a determination result of the determination unit.