JPH0484132A - camera - Google Patents

Abstract

PURPOSE:To allow the checking of an F value at the time of photographing without detecting the reflected light from a subject by displaying the stop value of a photographic lens at the time of electronic flash photographing and the stop value of the photographic lens at the time of light emission of an electronic flash device within a finder. CONSTITUTION:A power source battery is turned on and measurement and computation are executed when a photographer determines composition while viewing the finder 21 and pushes the 1st stroke of a shutter button at the time of photographing. The range of the usable F value is F4 to F16 from ISO information and the control range of GN if a subject distance is assumed to be 1m as a result of the measurement. Segments 23 corresponding to F4 to F16 of a display means 19 are then lighted and segments 23 corresponding to F16 are flickered. The checking of the F value at the time of photographing is possible in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a camera equipped with a strobe device that can change the amount of light emitted as appropriate.

(Prior art) Conventionally, as a strobe device installed in a camera, there is a flashmatic method in which the amount of light emitted is always constant and the aperture value (F number) of the photographing lens is controlled depending on the distance to the subject. This flashmatic method is mostly used.

The flashmatic method will be briefly explained.

Generally, the amount of light from a strobe is expressed by a numerical value called a guide number (GN). In order to achieve proper exposure, when the film sensitivity is 15O100, where F is the aperture value and D is the distance to the subject, GN = F - D...(1) It is necessary to satisfy the following relationship.

For example, if you photograph a subject at a distance of 1 meter using a GNN6J strobe and an aperture shutter with the aperture characteristics shown in Figure 6(a), the F value will be 16 from equation (1) above. At this point, light is emitted as shown in FIG. 6(b).

If the GN of the strobe is constant in this way, once the subject distance is determined, the F value of the photographing lens is determined in only one way during exposure, and the photographer cannot select the F value according to his/her shooting intention.

On the other hand, if the value of GN can be controlled, for example, in Figure 6(a), if a strobe with variable GN of 4 to 16 is used to photograph a subject at a distance of 1 m, GN = 16. F=16. GN=15 and F=1
5. . . . If the light is emitted at the timing of F=4 when GN=4, proper exposure will be achieved. In other words, depending on GN, Fig. 6(a),
(b) 1. (The time the lens shutter is open) The light can be emitted at any timing, and in terms of aperture, F,
The range (F16 to F4) can be used.

Japanese Patent Laid-Open No. 52-95224 discloses a device that can display strobe information in response to the above-mentioned GN variable.

Publication No. 61-34508, Publication No. 62-4618
Publication No. 0.

Utility Model Publication No. 50-31733, JP-A-59-1511
There are publications such as Publication No. 40.

(Problem to be solved by the invention) The above-mentioned Japanese Patent Application Laid-Open No. 52-95224, Publication of Utility Model Publication No. 61-3
In Publication No. 4508 and Japanese Utility Model Publication No. 62-46180,
The camera is equipped with a slide rule-like display board that displays the relationship between shooting conditions related to light control, that is, film sensitivity, F-number, subject distance, and GN, so that the photographer can set the conditions. The display requires mechanical space and display space, which leads to an increase in size, and it is difficult for beginners to read from the display board whether the conditions under which they are trying to take a picture are appropriate. Since it is provided on the external surface of the device or camera body, there is a problem that it cannot be seen when the photographer is looking at the viewfinder to decide on the composition or adjust the focus.

Furthermore, Japanese Utility Model Publication No. 50-31733 is a device that manually sets the GN, and displays an appropriate F value based on the set GN and distance information, and can be used for variable areas of the GN. It does not indicate the range of F value.

Furthermore, Japanese Patent Application Laid-open No. 52-151140 discloses a device that detects reflected light from a subject, controls the amount of light emitted, and displays the usable limit F value. The problem is that you need to do this.

SUMMARY OF THE INVENTION An object of the present invention is to provide a camera that can display a usable F value for the GN of a strobe device in a finder, which can be automatically converted without performing a test flash.

(Means for Solving the Problems) In order to achieve the above object, the configuration according to claim (1) provides a strobe device that can automatically change the amount of light emitted without detecting reflected light from a subject. The camera is characterized by comprising display means for displaying in the viewfinder the aperture value of the photographing lens during strobe photography or the aperture value of the photographing lens when the strobe device emits light, and also according to claim (2). With this configuration, in a camera equipped with a strobe device that can automatically change the amount of light emitted without detecting reflected light from the subject, the aperture value of the usable photographic lens is adjusted based on the shooting conditions during strobe photography. The invention is characterized by comprising display means for displaying in the viewfinder the range or the range of the aperture value of the photographing lens that can be selected when the strobe device emits light.
The configuration according to claim 3 further includes a display means for displaying a warning when the aperture value of the photographing lens set in flash photography is outside the exposure linked range. It is characterized by:

(Function) With the configuration described in claim (1), even if a strobe device that automatically changes the GN without detecting the reflected light from the subject is used, the photographer does not have to look at the viewfinder and do not know when shooting. F of
You can check the value.

In the configuration set forth in claim (2), even when using a strobe device that automatically changes GN without detecting reflected light from the subject, the photographer can check the settable F value by looking at the viewfinder. You can confirm or select the range.

In the configuration described in claim (3), the above claim <1) or (
2) In the configuration described above, a warning is displayed when the set F value is outside the exposure-linked range, so exposure failures can be prevented.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a configuration diagram of a strobe device according to an embodiment of the present invention, in which 1 is a power supply battery, 2 is a step-up circuit consisting of a DC/DC converter, etc., 3 is a main capacitor, and 4 is an Xe light emitting tube. (xenon) tube, 5 is a trigger means for starting the Xe tube 4, 6 is an X contact connected to the trigger means 5, 7
is the series resistor R connected in parallel to the main capacitor 3,
, R, and is proportional to the main capacitor voltage.
capacitor proportional voltage output means for outputting a voltage vA; 8
are the series resistances R, , R of the capacitor proportional voltage output means 7.

An A/D-C (Analog/Digital Converter) which is connected to the connection part 7a of and is a charging voltage measuring means for measuring the voltage of the main capacitor 3 based on the first voltage vA; 0 is an ISO information output means that outputs information related to film sensitivity (ISO); 11 is an F-number information output means that outputs aperture (F-number) information of the photographic lens; ,
12 is the base guide number (GN) information, for example, the voltage of the main capacitor 3 when it is fully charged, or the G that outputs information such as the ON state when the light is fully emitted when fully charged.
N information output means; 13 is a strobe zoom information output means for outputting such strobe zoom information since GN may change even with the same discharge energy due to operations such as changing the light distribution of the strobe; 14 is the object distance Information output means 9. ISO information output means 10. A light amount calculation means 15 receives data from the F value information output means 11 and calculates the amount of light (GN) necessary for illuminating the subject; 15 is a light amount calculation means 14. A/D/C8, GN information output means 12. Voltage calculation means receives data from the strobe zoom information output means 13 and calculates the voltage of the main capacitor 3 after light emission; 16 is a second voltage VD proportional to the voltage determined by the voltage calculation means 15; A D/A-C (digital/analog converter) 17 which is a calculated value proportional voltage output means to output the first voltage vA and the second voltage V
A comparator 18 which is a voltage comparison means for comparing D.
If the voltage at the comparator 17 is V A < V .

A light emission stopping means stops the light emission of the Xe tube 4 when
This is an F value setting means for selecting an appropriate value from the F values displayed.

Next, the operation of the above embodiment will be explained.

GN when the charge stored in the main capacitor 3 is discharged by the Xe tube 4 is generally determined by the discharge energy amount of the main capacitor 3, and the voltage of the main capacitor 3 before discharge is vII, and the voltage of the main capacitor when the discharge is stopped is vII. When the voltage of the main capacitor 3 is V7 and the capacitance of the main capacitor 3 is C, it is expressed as follows. Since the capacitance C is known here, GN can be controlled by measuring the voltage of the main capacitor 3 and stopping the light emission when a predetermined voltage is reached after the start of discharge.

More specifically, the voltage of the power supply battery 1 is boosted by the booster circuit 2, and the charge is stored in the main capacitor 3. The charging voltage of the main capacitor 3 is divided by the resistors R1 and R2 and is converted into the first voltage VA.
8 and the plus input section of the comparator 17.

In addition, the main condenser 3 after emitting light based on the GN necessary for illuminating the subject determined by the light amount calculating means 14
, the second voltage V from D/A-C16. is output to the negative input section of the comparator 17.

The Xe tube 4 is excited by operating the trigger means 5 when the X contact 6 is turned on, and emits light. When this light emission occurs, the voltage of the main capacitor 3 rapidly decreases, and the first voltage (2) also decreases. And the first voltage ■9 is the second voltage V. When it becomes lower than , the comparator 17 is reversed, and the light emission stopping means I8 connected in series with the Xe tube 4 is activated, and the light emission of the Xe tube 4 is stopped.

In this way, a strobe device is realized in which the GN automatically changes based on information about the object distance and the lSO2F value without detecting reflected light from the object.

FIG. 2 is an explanatory diagram showing an example of the display means of this embodiment, where 21 is a finder, 22 is a field of view range, and 23 is a plurality of segments such as LEDs and LCDs constituting the display means 19. The means 19 displays the F value in seven stages from 2.8 to 22 using segments 23.

FIGS. 3(a) to 3(c) are explanatory diagrams showing the operation of the display means in FIG.
2.8. The variable range of GN is 4 to 16.

The camera has a lens shutter that also serves as an aperture, and is equipped with an autofocus mechanism, and has ISO information (ISO = 1
00) is input to the light amount calculation means 14 by the DX code, and the main capacitor 3 is fully charged.

When photographing, the photographer determines the composition while looking at the viewfinder 2 and presses the first stroke of the shutter button (not shown), the power battery 1 is turned on and the measurements and calculations described above are performed. As a result of distance measurement, if the subject distance is 1m, the ISO information and GN control range (GN = 4 to 16)
Therefore, the range of usable F values is F4 to F16, and as shown in FIG.
The segment 23 corresponding to 6 flashes. The meaning of this display is that the aperture can be used in the range of F4 to F16 and is currently set to F16. In other words, in the initial state when the power supply battery l is turned on, the F value used for shooting is determined, and when the photographer presses the shutter button simultaneously with the first stroke and up to the second stroke, that is, when the shutter button is released. When the operation is performed, the Xe tube 4 emits light at that F value.

In this embodiment, at the time when the first stroke is pressed, the F value determined by the maximum controllable GN and the subject distance is set in the light amount calculation means I4.

At this point, with the first stroke of the shutter button, Figure 3 (a)
In this situation, if the photographer wants to use F8,
When the F value setting means 20 is operated and set to F8, the image shown in Fig. 3 (
The segment 23 corresponding to F8 blinks as shown in b). In this state, release the shirt (the second button of the shutter button).
stroke), strobe photography will be performed at F8.

In Figure 3(c), when the subject distance is 2m, the range of usable f-numbers when the first stroke of the shutter button is pressed and the currently set f-number F8 (blinking) are displayed. being done.

FIGS. 4(a) to 4(c) are explanatory diagrams showing the structure and operation of other display means, in which 24 indicates a pair of 7 segments 25 for displaying the F value, and a segment 2 for displaying a decimal point.
6, 27 is an arrow-shaped segment indicating the strobe shooting state, and 28 and 29 indicate that the set F value is the minimum value (MIN) and maximum value (MAX) of the usable range. They are a MIN segment and a MAX segment. Each of the segments is installed in the finder, and the minimum value refers to the maximum aperture area, and the F number is the maximum number.

Assuming that the camera conditions are the same as those described in FIGS. 3(a) to (C) above, in the first stroke of the shutter button, the arrow-shaped segment 27
lights up to indicate strobe shooting status, and the subject distance is 1m.
If so, the two 7-segment segments 25 display "16" and the MIN segment 28 lights up, indicating that F16 is the minimum aperture within the usable F-number range. Here, the F value setting means 20 sets the F value that the photographer wants to use.
When F8 is set, the MIN segment 28 disappears and only one of the seven segments 25 displays "8" as shown in FIG. 4(b). In addition, the photographer
When F4 is set by the value setting means 20, Fig. 4(c)
Only one of the seven segments 25 displays "4" and the MAX segment 29 lights up, indicating that F4 is the maximum usable aperture.

Next, a case will be described in which the above embodiment is applied to a single-lens reflex camera. The object distance information output means 9 outputs object distance information from a distance adjustment ring (not shown) of the lens as information for calculating a usable F-number range. Of course, in the case of an autofocus camera, distance measurement information from a distance measurement device is output. Furthermore, the aperture ring (not shown) indicates the maximum aperture value of the photographic lens being used and the aperture status at the time of shooting (how many stops from the maximum aperture is used).
is outputted by the F value information output means 11, and the usable F value is calculated by the light amount calculation means 14 as described above, and the value is displayed on the display means 1 explained in FIGS. 2 to 4.
Display by using 9.24. In this case, the display means 19 is configured to be able to display Fl, 4 to F32 in the segment 23 in order to respond to changes in the F value of various interchangeable lenses.

Furthermore, when a separate strobe device is attached to a single-lens reflex camera and used, GN information that is the basis of the strobe device needs to be outputted via the GN information output means 12.

By the way, when performing flashmatic flash photography with a camera that uses a lens shutter that also serves as an aperture, the shutter aperture characteristics are shown in Figure 6 (a).
Setting the F value that the photographer wants to use means setting the light emission timing. Therefore, the F
Specifically, as the value setting means 2o, the camera is equipped with a push button (F value up/down switch),
It is preferable to have a structure in which the F value is changed by one display each time the push button is pressed, and when the limit of the usable range is reached, no response is applied even if the push button is pushed any further.

In addition, with single-lens reflex cameras, the photographer uses the aperture ring to
Generally, it is possible to set a value, and it is easy to set it outside the usable F value range. Therefore, when using a display means similar to the display means 19 shown in FIGS. 2 and 3, it is necessary to place a display outside the exposure interlocking range next to a plurality of display elements 23 like the display means 30 shown in FIG. A warning display segment 31 is provided as a display means to indicate that the F value has been set, or all of the display elements 23 are blinked to display a warning. Further, in the configuration shown in FIG. 4, it is conceivable to display a warning by blinking at least one of the MIN segment 28 DEG MAX segment 29 and the 7 segment 25.

In the above embodiment, the step of F-number display is 1 aperture (IEV), but it can also be performed with 1/2 aperture or 1/3 aperture.

As described above, in this embodiment, when performing flashmatic exposure control using a GN variable strobe device, the ON/OFF settings that can be used at that time are
It is possible to select and set an appropriate F value from a plurality of F values corresponding to the following.

In other words, the photographer sets the aperture value according to the shooting intention, but since the settable F value range and the actual F value can be confirmed in the viewfinder, the user can use the camera while deciding on the composition. You can smoothly select the F value to use, and you will never miss a photo opportunity. Further, if the F value is set outside the exposure-linked range, a warning is displayed, so that exposure failures can be prevented.

Furthermore, displaying the shutter speed, F value, etc. for exposure control when not using a strobe is already commonly practiced in single-lens reflex cameras, and the present invention can be applied to known display devices. This can be achieved by simply adding a few functions and does not involve a significant increase in cost.

(Effects of the Invention) According to the configurations of claims (1) to (3), in a strobe device configured to be able to automatically change the amount of light emission (GN) without detecting reflected light from a subject, F value and range of F value that can be used for GN during strobe photography,
Since a warning is displayed in the viewfinder when an F value that is not linked to exposure is set, it is possible to provide a camera that reliably performs strobe photography in accordance with the photographic intention.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the configuration of a strobe device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the configuration of a display means of this embodiment, and FIGS. 3(a) to 3(c) are displays of FIG. 2. 4(a) to 4(c) are explanatory diagrams showing the structure and operation of other display means, FIG. 5 is an explanatory diagram showing the display means for warning display, and FIG. 6 is an explanatory diagram showing the operation of the means. (a) is an explanatory diagram showing the aperture characteristics, and Fig. 6 (
b) is an explanatory diagram showing light emission timing. 4... Arc tube, 9... Subject distance information output means,
10...ISO information output means, 11...F value information output means, 12...GN information output means, 13.
... Strobe zoom information output means, 14... Light amount calculation means, 15... Voltage calculation means, 19.24.3
1...Display means, 20...F value setting means. Special applicant Rico Co., Ltd. Director Hisashi Hoshino, 1 Convex Figure 2 Figure 3-'' Figure 4 Figure 5

Claims (3)

[Claims] (1) In a camera equipped with a strobe device that can automatically change the amount of light emitted without detecting reflected light from the subject, the aperture value of the photographing lens during strobe photography or the photographing lens when the strobe device fires A camera comprising display means for displaying an aperture value in a viewfinder. (2) For cameras equipped with a strobe device that can automatically change the amount of light emitted without detecting reflected light from the subject, the range of usable aperture values of the photographic lens based on the shooting conditions during strobe photography , or a camera characterized in that it is equipped with a display means for displaying in a viewfinder a range of aperture values of a photographing lens that can be selected when a strobe device emits light. (3) The camera according to claim 1 or 2, further comprising display means for displaying a warning when the aperture value of the photographing lens set during strobe photography is outside the exposure-linked range.