DE1301709C2 - AUTOMATIC EXPOSURE CONTROL FOR SHOOTING WITH PHOTOGRAPHIC CAMERAS WITH MIXED LIGHT - Google Patents

Description

The invention is based on an automatic which forms the subject of an ancient proposal Exposure control to achieve correctly exposed images with mixed light (lighting at the same time by daylight and flashlight), in which according to the German patent 1 290 805 in a camera both an automatic flash, in which the adjustment of the distance of the by the flash the aperture to be illuminated as well as an automatic daylight system are provided through which, depending on the the exposure time is set automatically in the background of the daytime brightness, and at ao of both automatic systems via the Aperture are coupled to each other and independent of the distance setting device of the lens fine special setting device that determines the aperture to select any aperture as is provided.

The object of the present invention is the technically correct implementation of the recordings according to the older proposal for various cameras and automatic feedback for control devices to ensure after admission to the starting position.

This object is achieved in that the distance setting device when setting a foreground area a safety switch in the flashlight ignition circuit closes and that the running shutter of the provided with the exposure control The camera releases a lock that untei spring force into the return of the distance setting device Releases the starting position assigned to a great distance.

The solution of further tasks that arise for individual exemplary embodiments is in each case in the description of these examples.

Only the core point of embodiment 4 (Fig. 3) is already emphasized here, because it constitutes progress in the relevant field: The general task to be solved is to achieve by means of an automatically operating device, without the camera user having to do anything. to regulate the aperture even for quite different foreground distances. If the foreground distance falls below a certain minimum distance, then, according to the known control principle for flash light, an increasingly smaller 55 ^! Aperture can be adjusted. This would, however, result in the great disadvantage that, in association with such small aperture openings, the automatic daylight setting sets long exposure times, which means that handheld shots (without a tripod) would no longer be possible. To avoid the object, such small apertures and long exposure times for mixing light images inevitably, is achieved according to a particular embodiment of the invention in that by the Entfemungs ^e 5 adjuster (^ controlled iris aperture only up to a predetermined aperture is closable and the further reduction of the exposure in the superficial area

tütig is achieved by reducing the flash light intensity (claim 4).

The invention is not intended for a specific camera, a specific automatic exposure control Daylight or tied to a specific flashlight device. A large number of known designs these elements can be determined according to the invention by suitable selection, mutual adaptation, Assemble minor additional facilities and temporal interaction to cameras that meet the assigned tasks if the associated operating instructions are observed.

The invention is illustrated in six exemplary embodiments, some of which are also shown in FIGS and their design explained. They have a number of common characteristics:

a) Devices are provided on the camera so that the flash unit is switched on can be that flash photography and Daylight recordings can be made at the same time;

b) the distance setting of the foreground for the formation of diaphragms takes place independently of the Depth of field setting of the lens or a symbol setting that replaces it;

c) the distance setting according to b) is timed to the activation of the daylight exposure control in advance;

d) the distance setting of the foreground according to b) inevitably brings about a corresponding one Rotation of the diaphragm ring and / or a corresponding change in the flash light intensity;

e) by the aperture setting (b to d) or by the flash light intensity setting the correct given lightning code has already been taken into account;

f) the daylight exposure control only regulates the exposure time after the previous final one Adjustment of the aperture according to b), c), d) and e).

It shows

F i g. 1 in a schematic representation of the setting elements with a linear aperture scale,

F i g. 2 also with non-linearized aperture scale,

F i g. 3 shows a schematic illustration similar to FIG. 1, but with a flashlight intensity that can be influenced.

Embodiment 1

The cameras in this group are characterized by a linearized aperture scale (scale equal Intervals on the aperture ring). The control of the flash exposure is shown schematically in FIG. On the distance setting ring 1, as a scale 2, the foreground distances for the flash photos are shown entered. The setting is made under the lens-fixed distance marker 3, the serves here at the same time to lock the ring 1. The ring slides coaxially around the aperture setting ring4, with which it can be coupled by means of the spring catch 8 for different guide number values 7. On the aperture setting ring 4 are the same Angle interval as the debris numbers 2 entered the numerical values of the aperture 5.

The f-number 5 set in each case is indicated by the mark 6 fixed to the lens. The series of numbers 2 and 5 correspond to the law of the international aperture series.

These numbers are arranged in such a way that for each guide number setting 7, 8 the product is off each aperture value and the associated distance

'° results in this guide number. This ensures that for each guide number coupling 7, 8 for each set distance 2 also the associated aperture 5, 6 is set. All of this happens automatically from admission to admission without any need

'5 de: Thinking about it. Only when changing the sensitivity of the film you have to pay attention to the coupling of a different guide number 7, 8.

The lock de? Distance setting ring 1 through the distance mark 3 by means of the teeth 9 is necessary because the ring 1 is housed sunk in the ring 4 under the train Coil spring 16 is standing, which tries to turn both rings clockwise. The coil spring 16 lies in a groove-shaped channel 17, which is along one

* 5 parts :; dtr periphery of the ring 4 runs. The The end of the spring 16 is attached to a pin 18, which is fixedly attached to the lens body, so that when the ring 1 is turned counterclockwise, the spring 16 is tensioned. This an-order serves the purpose of the distance setting ring 1 automatically in his after recording Starting position.

In order to ensure that every distance setting by means of the ring 1 also inevitably causes the If the flash unit is switched on, the following equipment is provided:

¹ An angular lever 11, which is under the train, a light spring 14, closes a switch '12, which is built into the line 13, which is used to operate the flashlight device. The switch 12 is always switched on when the ring 1 is outside of its rest position. If the locking mark 3 is released, then ring 1 moves under the tension of the spiral spring 16 in a clockwise direction until the stop 10 attached to ring 4 against the arm

'of the angle lever 11 strikes and this up to Stop pin 15 rotates. This opens the contact 12 and the flash unit is out of operation Geseüit.

■ jo Die; The locking mark 3 is released by a mechanical (possibly also electrical) connection, not shown, to the closure in the moment at which the closure reaches its end position (rest position).

If the general and special requirements described are met for the camera, then The process of automatic exposure control with mixed light is as follows -I measure from:

I The estimated (or measured by rangefinder or pacing) to the foreground distance of the subject to be illuminated with the flash is set on the focusing ring 1. the Setting the ring 1 inevitably also causes

the correct setting of the ring 4 and thus the aperture. Alludes to this aperture now the automatic daylight control belonging to the camera one by automatically making one of the taceshellickeit

regulates the corresponding exposure time. When the shutter is released, the background and foreground are automatically exposed. The draining lock releases the lock 3 and thereby causes the ring 1 to be returned to its rest position (by spring 16) and, at the same time, to interrupt the electrical line 13 to the '' flashlight device.

Everything that the operator has to consider for the mixed light recording is contained in the following Operating instructions:

a) when changing the film speed, set a new guide number 7 by means of the spring clutch 8th;

b) setting the foreground distance to ring 1;

c) usual setting for daylight exposure;

d) tripping.

Embodiment 2

The difference from Example 1 consists ^a5 only in that the camera has no linearized aperture scale, but one having unequal intervals (such as a logarithmic scale). In this case, the simple solution according to AusfUhrungsbeispiel 1 fails F i g. 2 shown.

On the distance setting ring 21, the foreground distance numbers 22 are at equal intervals (linearized as in example 1). A second ring, the aperture setting ring 23, is located coaxially within the ring 21 and is connected to this by the spring catch 29, which as in FIG. 1, each set to the given guide number of the guide number row 28 on the ring 21 can be when a change in the guide * 5 z. B. when changing the film speed occurs. The guidelines 24 are provided in a known manner on the diaphragm setting ring 23. Every Some of the seven guidelines shown combine the set distance figure with the fixed objective Distance mark 25. The ends of the guidelines 24 highlighted by arrowheads have on inner circumference of the ring 23 to each other the same distances as the f-number 26 am the same ring 23, which above the aperture mark 27 indicates the aperture that has been set in each case.

This comparatively simple trick achieves that with linearized, on the circumference of the Ring 21 arranged distance numbers 22 by j setting the 'given guideline 24 to j the distance mark 25 the change in the aperture according to the law takes place in the arrangement of the diaphragm row 26 and thus identical in the arrowheads of the guidelines 24 is given. Even if the number of oil is changed by a new clutch (28, 29), the Obtained from this solution given above; for the series of guide numbers 28 is linearized according to the same law as the series of distance numbers 22. Even with new guide numbers, the The aperture corresponding to the distance is correctly set.

The composite ring 21/23 of this second case is therefore equivalent to the ring composition 1 and 4 in exemplary embodiment 1. All the possibilities in case 1 can also be used in case 2, analogously Find application. The operating instructions to be used for embodiment 2 are the same as in example 1 (see above).

Example 3

The distinguishing feature of this group is a camera whose automatic daylight setting sets a time-aperture pairing. In such cases, compared with Embodiments 1 and 2, the order of the settings is for mixed light shots different in that only the daylight automatic for importing is brought. The time-diaphragm pairings found in this way are now turned into by setting the foreground distances according to example 1 the certain - necessary for the flash exposure - Aperture selected, which inevitably means the correct exposure time for daytime images is set. Based on example case 1 and the designations of FIG. 1 is now the operating instructions:

a) b .i Change of the sensitivity of the film

a new guide number 7 by means of the spring clutch 8,

b) Introducing the time-aperture pairing through the automatic daylight;

c) setting the foreground distance to ring 1;

d) remaining settings for daylight recording;

e) tripping.

Embodiment 4

For this group, which is to be considered particularly important, those cameras that were suitable for example cases 1 and 3 come into consideration. that is, cameras with a linearized aperture scale; However, cameras with non-linear diaphragm division (example case Z) can also be used if the configuration given below is modified accordingly.

The characteristic of this in. Example of FIG. 3 embodied group is that the regulation of the Flash exposure depending on the foreground distance either automatically by regulation the aperture or by changing the flash light intensity. A flash unit must therefore be used can be used, which allows the activation of partial energies in several stages. Most appropriate is a transistor-controlled device of this type with push-button switching for each Stages. A corresponding number of small pushbuttons are attached to the lens automatic control can be operated. (For flash units whose intensity is determined by series resistors is regulated, a regulating resistor with contact steps occurs in place of the pushbuttons Place the pushbuttons. Embodiment 4 only deals with the pushbuttons.

539

The need to regulate the flash lighting in the twofold stated manner arises result from the following consideration:

If foreground objects near the camera are to be illuminated by flash light, a very small aperture would have to be used according to the rule. But then with unfavorable light conditions for daylight intake there is a risk of ^; that the automatic exposure control can no longer regulate the exposure time or only an exposure time that is so long that taking pictures without a tripod is no longer an option.

For such cases, which may often occur in practice, the solution according to the invention is used The basis is based on the fact that for mixed light shots (also for flash light shots alone) a certain Aperture is not undershot. Where there is a further reduction in the effect of the flashlight appears necessary on film or plate, this reduction is achieved by reducing the Flash light energy made in stages.

When setting, the transition from diaphragm control to light energy control takes place automatically when a predetermined minimum diaphragm opening is reached. In the chosen and in the fig. 3, the aperture 8 is the smallest aperture used for flash light and mixed light. In FIG. 3, the changes are clearly illustrated which result from the described embodiment 1 (FIG. 1). The distance setting Si with the enuciuunity numbers 52 and the locking stationary mark 53 are known from embodiment 1, as is the arrangement of the guide numbers 54 and the associated spring catch 55. The use of a third ring, the auxiliary ring 5, which is constantly connected to the distance setting ring 51, differs the spring wheel 55 of the guide number clutch remains coupled *. Towards the inside, however, the coupling of the auxiliary ring 56 is not a permanent one, which will be described later.

In the auxiliary ring 56, the spiral spring 57 is concealed in the annular groove 58 and on one end attached to the pin 59 fixed to the lens. The mode of action of the spring 57 is here again, that this in the rotation of the rings 51/56 necessary to adjust the distance against the Is tensioned clockwise. During the recording remains due to the locking by the stationary Mark 53 of the distance setting ring 51 under this spring tensioning.

In this example, too, it is provided - but not shown - that after the expiry of the Locking by a preferably mechanical connection with this lock is released by the mark 53, so that the ring 51 under the train of the spring 57 returns to its original position.

The second ring, the aperture ring 60 is, as the innermost of the three rings shown on this ring as previously entered the aperture values 61, de ^r s set value is displayed again by the stationary brand 62nd So far everything is known and understandable from Example 1. Now, however, follow those parts that are related to the regulation of the flash light intensity:

Permanently attached to the middle ring 56 is a switch arm 63, the free end of which is thus sprung is that when swiping over the four depicted pushbuttons 67 to 64, each of the set small distances of 3.5 to 2.5 to 1.8 and 1.3 m each presses one of the buttons and so that a corresponding partial energy of the flashlight unit switches on. The dimensioning of the partial energy takes place here again according to that number-I law that z. B. in the sequence of the guide numbers for ! Application comes. The gradation of the light intensity is as follows:

Key 64 = 25% of the full intensity of the device

Key 65 = 36% of the full intensity of the device. Key 66 = 50% of the full intensity of the device Key 67 = 72% of the full intensity of the device

For the effect on the film, reducing the light intensity is equivalent to using it the smaller apertures 32, 22, 16 and 11. By using partial energies of the flash unit

So the disadvantages of using it can be smaller ! Glare should be avoided. Another advantage of this type of regulation is that it saves batteries of the flash unit. Without the photographer even noticing it, according to this invention,

»5 the correct choice of the Control means: aperture or light intensity change.

At the κ clear distances from the foreground (in the example 20 to 5 m) the aperture is reduced from 2.4 to 8. If the setting of the ring 51 goes over smaller distances of less than 5 m . κη the aperture is no longer reduced (this remains set to 8), rather the gradual switch-off of the light intensity occurs automatically by pressing the buttons 67, 66, 65 and 64. This "switchover" to the other means of regulation

ι necessarily takes place in the following way:

The nose-shaped one is located on the inside of the ring 60

Stop 68. In the position shown dts Ent-

Fernungsringes, so at 5 ra foreground distance (aperture setting 8), is through the fixed (lens-fixed) spring-loaded latch 69, the stop 68

j j and thus the ring 60 in its instantaneous

Position held. This means that the aperture remains unchanged at aperture value 8. The distance setting ring is used 51 rotated further counterclockwise, the connected rings 51 are released and 56 of ring 60, because a spring-loaded ball detent 77, which in the absence of resistance as

so coupling is sufficient, is released from the detent position unc the further turning movement to the left joins in 'As already described in example case 1, and Here a device is provided, at the same time with each distance setting inevitably also det

Switch on the safety switch for the flashlight unit. The angle lever 72, switch 73, which is switched into the line 74, and the spring 75, which keeps the switch T, I closed, as long as the setting ring 1 fell, serve this purpose

j is outside the rest position

ι This means that all of the schematically illustrated drives were described, which would take the setting and output itself. Only those come now

■ It is the turn of the institutions that have the task

⁶ S after the exposure, the starting position must be restored. First there is the already mentioned connection, not shown, between the end position of the relaxed closure un

the locking mark 53, through which the locking 53 is released after the closure has expired, so that, under the action of the spring 57, the rings 51 and 56 tend towards their rest position in a clockwise direction. On the way there the following happens:

An Entriegelungskeii 70 is attached to the auxiliary ring 56 at the bottom and covered, namely at such an angular distance on the stationary bolt 69 that it only reaches this bolt in the end position of the rings 51/56. At this meeting the Entriegelungskeil 70 moved by a corresponding stop face leaning on the bolt 69 the latter radially outwardly such that the latch remains retracted and the lug-shaped stop 68 is no ¹ S resistance. This ensures that the aperture ring can be freely moved 60 over the entire aperture range in the rest position of Entfernungseinstellringes 51 so that can be done ^a0 circuit daylight shots with all apertures unobstructed so when not using the flash without special environmental. On the same return path of the two rings 51 and 56 to the rest position, the stop 71 attached to the auxiliary ring 56 also comes into operation. ^a 5

Shortly before reaching the rest position, he meets ilen arm of the angle lever 72, moves it up tum stop pin 76 and thus causes switch 73 to be switched off. (This process is the same like the one already described in Example 1.)

Finally, when the rings 51 and 56 are in the rest position, the following takes place: The locking position of the ball catch 77, which serves as a coupling, on the ring 60 is chosen so that all three coupled rings do not move back under ³ ^ <em tension of the spring 57 the first ring 60 comes to a standstill when the diaphragm position 2.4 is reached. The breakpoint of the other two rings is moved forward by a few degrees in the clockwise direction, so that when the ring 60 is stationary, the other two rings are still in motion. The lug of spring 57, which continues to act on ring 60, then causes ball catch T7 to be removed from its rest position in ring 60 and continues with ring 56 to its end position. In this way the rings 60 and 56 are decoupled, the diaphragm ring 60 is free to move on its own and can be brought into any position for daylight shots without a flash so that the small diaphragms can be used again. The coupling catch 77 does not interfere with this because it is outside the movement path of the ring 60 in the end position of the ring 56

This ensures that the position of rest after each individual exposure with mixed light is inevitably established and that from this rest position all three types of recording (day, Flash and mixed light shots) are immediately possible.

That the varied tasks of this example case have been solved can be seen from the fact that for automatic Mixed light shots also in example 4 the same simple operating instructions apply as in Example case 1:

a) when changing the film speed, a new guide number 54 is set using the spring clutch 55;

b) setting the foreground distance at if ring 51;

c) usual setting for daylight exposure;

d) tripping.

Exemplary embodiment 5

The subject of this group of examples is cameras, which instead of the numerical settings only use so-called exposure symbols for aperture, time and distance, so that the Operators according to the nature of the subject (portrait, group, landscape) and the type sets a certain symbol for the cloud cover. Most cameras of this type are connected A flash exposure is also provided for the sequence of symbols, but in such a way that either a daylight exposure or a flash exposure can be set, but not both at the same time.

According to the invention, a switching option is provided for such a camera at the symbol "flash light" which allows the flash light recording to be carried out simultaneously with the one set by the symbol. To take daylight exposure, the automatic system being based on the teachings and exemplary embodiments already described, depending on the given conditions of the exposure control. The proposed additional switch on the flashlight symbol can preferably consist of an electrical switch that is inserted into the line between the shutter and the flashlight device.

Embodiment 6

From the previous group of examples 5, that camera type is now picked out in which a certain time-aperture pairing is set by choosing the exposure symbol and in which the possibility is provided to set certain apertures within this selected pairing, so that automatically the associated Time adjusted. Such a type of camera can be treated in the same way as a camera according to embodiment 3. It is provided with a distance setting ring etc. according to FIG. 1. The operating instructions for mixed light photography are then:

a) when changing the film speed, setting a new guide number 7 by means of the spring clutch 8;

b) setting an icon;

c) Setting the foreground distance to Ringl;

d) remaining setting for daylight recording;

e) tripping.

1 sheet of drawings

3539

Claims (6)

1 301 70S claims: 1. Automatic exposure control to achieve Correctly exposed pictures with mixed light (illumination evenly by daylight and flashlight), whereby in one camera both an automatic flashlight, in which the setting the distance of the foreground object to be illuminated by the flash, the aperture as well as an automatic daylight system are provided through which depending the exposure time is set automatically by the daytime activity prevailing in the background and both automatic systems are coupled to one another via the panel and are independent of the distance setting device the lens has a special setting device that determines the aperture to choose any aperture, according to patent 1290805, characterized in that, that the distance setting device (1, 51) when setting a foreground area a safety switch (12, 73) in the flashlight? ündkreis closes and that the expiring The shutter of the camera equipped with the exposure control releases a lock that releases the Return of the distance setting device under Releases spring force in the starting position assigned to a large distance. 2. Automatic bookkeeping control Claim 1, characterized in that the linearized distance scale (2 ") with the non-linearized Aperture scale (26) is connected by a guide line system (24). 3. Automatic exposure control according to claim 1 and 2, characterized in that with exposure value coupling between aperture and time, the aperture corresponds to the set one Removal of the foreground is formed. 4. Automatic exposure control according to claim 1 to 3, characterized in that through the aperture control controlled by the distance setting device (51) the aperture (60) can only be closed up to a predetermined aperture and the further reduction of the Exposure in the foreground area automatically by reducing the flash light intensity is achieved. 5. Automatic exposure control according to claim 4, characterized in that the Control of the flash light intensity by a control arm (63) is carried out on a with the Aperture ring (60) via a detachable catch (77) coupled auxiliary ring (56) is attached and the Pushbuttons (64 to 67) for several levels of flash light intensity actuated that the switchover from the control by changing the aperture to changing the flash light intensity takes place by means of a stop (68, 69) that can be overcome in the predetermined aperture and that the catch (77) of the auxiliary ring (56) is released in the starting position. 6. Automatic exposure control according to one of the preceding claims with a Changeover switch for different work areas, characterized in that the changeover switch in a recording can be brought with mixed light assigned position and this position through a symbol is indicated.