JP3533207B2 - Stereo photography equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereo adapter for use in stereo photography and a stereo photography apparatus having a camera to which the stereo adapter can be attached.

[0002]

2. Description of the Related Art The principle of a stereo photography apparatus will be described with reference to FIG. The stereo adapter 12 mounted on the front side of the taking lens 11 on the object side has second reflecting mirrors 13a and 13b having a predetermined angle to the left and right with respect to the optical axis of the taking lens 11, and the second reflecting mirrors 13a and 13b. The first reflection mirror 14a, substantially parallel to
14b are arranged. The subject 15 is the first and second reflection mirrors 14a, 14b, 13a, 13b.
Is divided into two parts, and an image is formed by the taking lens 11 on one taking frame (film) 16 of length d. This photographic film is observed as a stereoscopic image by separately observing the two-divided images 15a and 15b with the left and right eyes.

When this stereo adapter (hereinafter referred to as "adapter") is attached to a single-lens reflex camera for photographing, the boundaries between the left and right images in the viewfinder field are conventionally unclearly recognized, so that the left and right images are not visible. It was difficult to see each as an individual image.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. Even when an adapter is attached to a single-lens reflex camera and an image is taken, two left and right object images observed in the viewfinder are observed. It is an object of the present invention to provide a stereoscopic photography device capable of clearly recognizing a boundary.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a stereo adapter for projecting two images of the same subject viewed from different viewpoints adjacent to one frame of film, and a single-lens which can be mounted on the front end of the photographing lens. in stereo photography apparatus and a Refuka camera, detecting means and for detecting the presence or absence of the mounting of the stereo adapter to SLR main <br/>La; detection means detects the mounting of the stereo adapter to SLR camera when, visually emphasizing boundaries emphasizing means the boundary between the two images observed in the finder field of view of the SLR camera; characterized by having a. According to this configuration, when the adapter is attached to the single-lens reflex camera to take a picture, the left and right 2
The boundary between two subject images can be clearly recognized.

The boundary emphasizing means may have a liquid crystal display section provided on the focusing screen along the boundary, and the liquid crystal display section may be energized to visually emphasize the boundary.

As another aspect, the boundary emphasizing means may be configured to advance the rod-shaped member on the focusing screen in synchronization with the mounting of the stereo adapter.

[0008] detecting means, single-lens camera-side contact provided in Refuka camera, stereo to SLR camera by detecting the presence or absence of conduction between the adapter side contact provided in the stereo adapter in correspondence to the camera contacts It is possible to detect whether or not the adapter is attached.

Further, the photographic lens front stereo adapter and SLR main <br/> La, it preferably has a connectable structure to one another via a bayonet mount having a plurality of engaging claws. In this case, when the stereo adapter is attached to the front end of the taking lens via the bayonet mount, the contact on the camera side and the contact on the adapter side can be electrically connected.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to illustrated embodiments. FIG. 1 is a perspective view showing a camera 20 to which the present invention is applied and an adapter (stereo adapter) 100 attached to the camera 20. The camera 20 is a lens shutter camera with a built-in zoom lens, which includes an AE mechanism, an AF mechanism, a PZ (power zoom) mechanism, and a screen size switching mechanism. FIG. 2 shows a control block of the camera 20.

The camera 20 has a fixed lens barrel 22 integrally formed on the front portion of its camera body 21.
A zoom lens barrel 23 that moves back and forth in the front-rear direction of the camera 20 based on the operation of the zooming switch 36 is provided inside the unit 2. The zoom lens barrel 23 is the zoom lens barrel 2
3, a cam pin (not shown) provided in 3 engages with a cam groove 26a formed in a cam ring 26 fitted to the zoom lens barrel 23, and the cam ring 26 is rotated by a zoom motor 28. It has a well-known structure which is moved back and forth by. Although not shown in the figure, a gear train (not shown) is interposed between the drive pinion 28 a of the motor 28 and the outer peripheral gear 26 c formed at the rear end of the cam ring 26. The zoom motor drive circuit 27 is controlled by the control means 120 such as a microcomputer so as to set the zoom lens barrel 23 to a predetermined focal length, and the code pattern 26b formed on the outer periphery of the cam ring 26 and the code pattern 26b. The zoom motor 28 is driven so as to zoom the zoom lens barrel 23 while grasping the current focal length by the zoom code brush 29 that slides on the code pattern 26b and detects the rotational position of the cam ring 26.

At the upper part of the front wall 21a of the camera body 21,
A finder objective window 31 is provided, and an infrared projector 32 and an infrared receiver 33 of the active distance measuring device are provided on the left and right of the finder objective window 31. Further, the front wall 21a is provided with a stroboscopic light emitting portion 34 and a light receiving portion 35 having a photometric sensor (not shown) therein.

A release button 38 is provided on one side of the upper part of the camera body 21, and the zooming switch 3 for changing the focal length of the photographing lens is provided behind it.
6 is provided. This zooming switch 36
Wide zoom switch 36 that changes the focal length to the wide-angle side
a and a tele-zoom switch 36b for changing to the telephoto side. A screen size switching mechanism 40 provided in the camera 20 is provided at the center of the upper portion of the camera body 21.
A screen size changeover switch 37 for operating (FIGS. 3 to 5) is provided. The switch 37 is used to slide the left and right sides to change the size of the shooting screen into two sizes, namely
This is an operation switch for switching between the standard size of 24 mm x 36 mm and the so-called panoramic size (horizontal size) of 13 mm x 36 mm.

FIG. 3 shows the screen size switching mechanism 40 and the finder optical system 60 provided in the camera 20. The real image type finder optical system 60 optically includes, from the objective side, a moving lens 61 and a moving lens 62 as an objective optical system, an image erecting prism 63 as an erecting optical system, and a photographing range at the time of standard size photographing. A field frame 64 having a frame and defining a field of view at the time of standard-size shooting;
An eyepiece lens 65 as an eyepiece optical system is provided, and the viewfinder magnification can be varied by moving the moving lens 61 and the moving lens 62 in the front-back direction along the viewfinder optical axis O in a predetermined relationship. Have

Image erecting prism 63 facing the field frame 64
A panoramic field frame 41, which is integrally formed with a screen size regulation plate 43 which is a component of the screen size switching mechanism 40, between the exit surface of the device and the field frame 64 and which regulates the field of view at the time of panoramic size photography can be moved forward and backward. It has been configured.
The panoramic field frame 41 is a screen size switching mechanism 40.
When the size of the shooting screen is switched to the panorama size by, the size of the viewfinder field is changed to the size corresponding to the size of the shooting screen that has been changed to the panoramic size. A mask member that shields light of a certain width. The screen size switching mechanism 40 will be described below.

As shown in FIGS. 4 and 5, the camera 20
The screen size switching mechanism 40 provided so as to correspond to the photographing opening 19 has a pair of L-shaped screen size regulating plates 42 and 43. The screen size regulation plate 42 has a guide portion 42 a and a screen regulation portion 42 b which are orthogonal to each other, and the screen size regulation plate 4
3 is a guide portion 43a and a screen regulating portion 43 which are orthogonal to each other.
b. The screen size regulation plate 43 is also
The panoramic visual field frame 41 described above is integrally provided at a position offset rearward from one end of the upper portion thereof. The panoramic field frame 41 is formed with an opening 41a for forming a viewfinder field having a size corresponding to a panoramic shooting screen. The upper and lower sides of the opening 41a are light-blocking so as to block a certain width above and below the normal viewfinder field. It is formed as the portion 41b.

The screen size regulating plate 42 has a guide portion 42a, and a linear guide groove 42 along the longitudinal direction thereof.
Two guide pins 49a and 49b fixed to a fixing portion (not shown) of the camera body 21 are fitted into the linear guide groove 42c. As a result, the screen size regulation plate 42 is fixed by the guide pins 49a, 49a.
Due to the fitting relationship between b and the linear guide groove 42c, the linear guide groove 42c is movably guided in the vertical direction within the effective length range.

A pair of screen size control plates 42, 43
Are arranged in a substantially point-symmetrical relationship with respect to an intersection D of the vertical centerline B-B and the horizontal centerline C-C of the photographing aperture 19, and the rectangles corresponding to the photographing aperture 19 are arranged. It constitutes the opening.

The screen size regulation plate 43 has a guide portion 43a and a linear guide groove 43 along the longitudinal direction thereof.
Two guide pins 50a and 50b fixed to a fixed portion (not shown) of the camera body 21 are fitted into the linear guide groove 43c. As a result, the screen size regulation plate 43 has the guide pins 50a, 50
Due to the fitting relationship between b and the linear guide groove 43c, the linear guide groove 43c is movably guided in the vertical direction within the range of the effective length of the linear guide groove 43c.

Further, the screen size regulation plate 42 has a support pin 5 at the intersection of the guide portion 42a and the screen regulation portion 42b.
1 and the screen size regulation plate 43 includes the guide portion 4
A support pin 59 is provided at the lower end of 3a. Rotation support pin 5 fixed to a fixed portion (not shown) of the camera body 21
An interlocking bar 52 is rotatably supported by 3, and a long hole 52a at one end and a long hole 52b at the other end of the interlocking bar 52 are fitted in the support pins 51 and 52, respectively. A coil spring 54 is wound around the rotation support pin 53. One end of the coil spring 54 is attached to an engagement pin 55 which is planted in a fixed portion (not shown) of the camera body 21, and the other. The end portion is engaged with an engagement pin 56 that is planted in the interlocking bar 52. As a result, the interlocking bar 52 always receives a rotational biasing force in the clockwise direction of FIG. 4 about the rotational support pin 53, and in its free state, the upper end of the linear guide groove 42c abuts the guide pin 49a. Then, the linear guide groove 43c is rotated until the lower end of the linear guide groove 43c is brought into contact with the guide pin 50b. In addition, the interlocking bar 52 and the rotation support pin 53
Is configured so that the vertical movement of the screen size regulation plate 42 can be transmitted to the screen size regulation plate 43 as the same vertical movement amount in the opposite direction with respect to the center line BB. .

On the other hand, in the state shown in FIG. 4 in which the screen size regulating plate 43 is located above, the panoramic visual field frame 41 is located between the visual field frame 64 and the exit surface of the image erecting prism 63 facing the visual field frame 64. Withdraw from the viewfinder optical path and set the size of the viewfinder field to the normal size corresponding to the standard size. Further, the panoramic field frame 41 is displayed in the state shown in FIG. 5 in which the screen size regulation plate 43 moves downward,
With this movement, the light-shielding portions 41b positioned above and below the opening 41a are moved to the upper and lower sides of the viewfinder field, with the light-shielding portions 41b positioned above and below the opening 41a advancing to the viewfinder optical path between the exit surface of the image erecting prism 63 facing the field frame 64 and the field frame 64. Position it so that the viewfinder field size is a small viewfinder field size that corresponds to the panorama size.

An electromagnet 58, which can be switched between excitation and demagnetization by the control means 120 (FIG. 2) based on the screen size changeover switch 37, is fixed to a fixed portion (not shown) of the camera body 21, and the interlocking bar 52 is provided. An armature 57 such as an iron piece is fixed at a position facing the electromagnet 58. Therefore, when the electromagnet 58 is excited, the armature 57 is attracted and the interlocking bar 52 is rotated counterclockwise in FIG. 4, and the screen size regulation plate 42 is moved upward from the state in FIG. 4 and moving the screen size regulation plate 43 downward from the state of FIG. 4 to move the respective screen regulation portions 42b and 43b to the photographing opening 1.
The screen size can be switched to the panorama size by advancing within 9.

As shown in FIGS. 1, 6 and 7, the front end portion 23a of the zoom lens barrel 23 and the adapter 100 are constructed so that they can be connected to each other using a known bayonet mount. That is, the zoom lens barrel 23 has a plurality of engaging claws 24 on the outer periphery of the front end portion 23a, and the adapter 10
0 is the front end portion 23a of the zoom lens barrel 23 on the rear wall 101.
It has a connector part 102 for connecting with. The connector portion 102 has a mount portion 111 with which the front surface of the engaging claw 24 abuts, and an engaging claw 110 that is located slightly behind the mount portion 111 and is formed in the same number as the engaging claw 24. . The plurality of engaging claws 110 are attached to the zoom lens barrel 23.
The adapter 100 is attached to the camera 20 by engaging with the side engaging claw 24.

At the front end portion 23a of the zoom lens barrel 23,
A plurality of electric contact pins 25 are formed to project. The plurality of electric contact pins 25 are provided on the front end portion 2 of the zoom lens barrel 23.
When 3a is connected to the adapter 100, the connector portion 10
It is configured to be electrically connected to a plurality of corresponding electrical contact lands 112 formed on the second mount portion 111. The electrical contact pin 25 and the electrical contact land 1
Reference numeral 12 indicates whether or not the adapter 100 is attached to the camera 20 by the stereo adapter attachment detector 134, and the mirror angle information is transmitted to the mirror motor drive circuit by the encoder 181 provided in the adapter 100.
Further, it is provided for supplying a drive current from the camera 20 side to the mirror drive motor provided in the adapter 100.

In the camera 20 according to the present invention, the switch 3
The size of the shooting screen can be switched to the panorama size by the operation of 7, or the stereo adapter mounting detection unit 1
When 34 detects the mounting of the adapter 100, the electromagnet 58 of the screen size switching mechanism 40 is excited to switch the size of the photographing screen to the panoramic size. This control is performed by the control means 120. According to this configuration, when taking a stereo photograph, the same subject is photographed on the left and right sides of one standard-size film frame, and the left and right images are formed as a vertically long screen. On the other hand, since the left and right subject images are formed as a horizontally long screen, it is possible to obtain a stereoscopic photograph (FIG. 9) with a sense of reality. It should be noted that this configuration can be applied not only to the lens shutter camera but also to a single lens reflex camera.

The camera 20 has a stereo visual field switching mechanism 140 shown in FIG. This stereo visual field switching mechanism 140 is provided in the camera body 21 in the vicinity of the finder optical system 60, and has a stereo visual field plate 141 positioned adjacent to the panoramic visual field frame 41 and parallel to the panoramic visual field frame 41. is doing. The stereo view switching mechanism 140 is not shown in FIG.

The stereo visual field plate 141 has a pair of linear guide grooves 143 formed in the vertical direction, and a fixed portion (not shown) of the camera body 21 fitted in the linear guide grooves 143. Guide pin 14 fixed to
4, the linear guide groove 143 is supported so as to be movable in the vertical direction within the range of the length thereof. A tension spring 146 is hooked between an engaging portion 145 on one side of the stereo visual field plate 141 and an engaging pin 147 implanted in a fixed portion (not shown) of the camera body 21, and Thus, the stereo visual field plate 141 is constantly urged downward by the action of the tension spring 146. The stereo visual field plate 141 also has a light blocking portion (stereo photography visual field forming member) 142 that can move forward and backward in the finder optical path, and this light blocking portion 142 is arranged side by side on the shooting screen size during stereo photography, that is, on the film surface. An opening 142a for forming a viewfinder field having a size corresponding to the screen size of either one of the two images formed by the same subject is formed.

When the stereo adapter mounting detection unit 134 detects the mounting of the adapter 100, the electromagnet 149 excited by the control means 120 based on the detection is fixed to the fixed portion (not shown) of the camera body 21. An armature 148 such as an iron piece is fixed to the stereo visual field plate 141 at a position facing the electromagnet 149. With this configuration, in the state where the electromagnet 149 is demagnetized, the stereo visual field plate 141 is
2 is retracted from the viewfinder optical path, and when the electromagnet 149 is excited, the electromagnet 149 attracts the armature 148 against the tension spring 146, and the light shielding portion 142 is moved to the viewfinder optical path. It is moved to the position Q indicated by the chain double-dashed line in FIG. 10 to be advanced, and the viewfinder field is switched to a viewfinder field of a size corresponding to the shooting screen size during stereo photography.

Therefore, as shown in FIG. 12, since the panoramic field frame 41 and the light shielding portion 142 of the stereo field plate 141 overlap the viewfinder field V when the photographing screen size is the standard size, the upper and lower ends of the opening 41a. A portion indicated by a diagonal line AV in the drawing, which is regulated by the left and right ends of the opening 142a, is visually recognized as a viewfinder field during stereo photography. Therefore, according to this configuration, when the stereoscopic photography is performed, the viewfinder field and the actual photography screen correspond to each other, so that the actual photography range is not mistakenly recognized in the stereo photography.

Instead of the above-mentioned stereo visual field switching mechanism 140, for example, as shown in FIG. 14, a viewfinder visual field at the time of taking a stereo picture is defined by projecting from the upper rear of the adapter 100 toward the rear (camera 20 side). The light-shielding member (stereo photographing field forming member) 103 may be formed integrally with the adapter 100. In the light blocking member 103, when the adapter 100 is attached to the camera 20, a light blocking plate portion 104 having an opening 104a formed in the center thereof is located in front of the finder objective window 31 of the camera 20, and the opening 104a is the light blocking member. It plays the same role as the opening 142a of the portion 142. The light-shielding plate portion 104 is formed so as not to come into contact with the finder objective window 31 and to be positioned very close to the finder objective window 31 in a state where the zoom lens barrel 23 is most stored in the fixed lens barrel 22. ing.

In the above description, the light shielding member 103 and the light shielding portion 142 are mentioned as specific examples of the stereoscopic photographing visual field forming member, but the stereoscopic photographing visual field forming member is not limited to these concrete examples. The stereoscopic imaging visual field forming member is, in short,
Anything that allows the photographer to visually recognize the viewfinder field range corresponding to the shooting screen during the stereoscopic photography is acceptable. For example, if the liquid crystal is masked outside the photographing range on the field frame 64 during stereo photography, and the stereo adapter mounting detection unit 134 does not detect the mounting of the adapter 100, the liquid crystal portion is not energized and the liquid crystal portion is blocked. When the stereo adapter mounting detector 134 detects the mounting of the adapter 100 in the light-transmitting state, the liquid crystal portion may be energized to make the liquid crystal portion opaque or semi-transparent. If a transparent plate on which a shooting range frame indicating a shooting range during stereo photography is drawn is provided in the optical path of the viewfinder so that the stereo adapter mounting detection unit 134 does not detect the mounting of the adapter 100, the above-mentioned transparent When the plate is retracted from the finder optical path and the stereo adapter mounting detection unit 134 detects mounting of the adapter 100. It may be configured for advancing the transparent plate finder optical path.

The camera 20 also has a stereo visual field varying mechanism 150 shown in FIG. Like the stereo visual field switching mechanism 140, the stereo visual field changing mechanism 150 is provided in the camera body 21 in the vicinity of the finder optical system 60 and moves back and forth in the finder optical path between the visual field frame 64 and the eyepiece 65. The zoom lens 152 has a variable power lens 152. It should be noted that this stereo visual field varying mechanism 150 is shown in FIG.
Not shown in FIG.

The variable power lens 152 is a so-called magnification lens for enlarging and observing the finder visual field AV shown in FIG.
It is supported by 53. This lens frame 153 is
It is fixed to a driven plate 151 that can move in the vertical direction. The driven plate 151 has a pair of linear guide grooves 154 formed in the vertical direction, and is fixed to a fixed portion (not shown) of the camera body 21 fitted in the linear guide grooves 154. The guide pin 155 supports the linear guide groove 154 so as to be vertically movable within the range of the length thereof. A tension spring 157 is hooked between an engagement portion 156 on one side of the driven plate 151 and an engagement pin 158 implanted in a fixed portion (not shown) of the camera body 21. The driven plate 151 is constantly urged downward by the action of the tension spring 157.

When the stereo adapter attachment detector 134 detects attachment of the adapter 100 to the fixing portion (not shown) of the camera body 21, the electromagnet 160 excited by the control means 120 based on the detection is fixed. An armature 159 such as an iron piece is fixed to the driven plate 151 at a position facing the electromagnet 160. With this configuration, when the electromagnet 160 is demagnetized, the driven plate 151 is positioned at the lower position shown in FIG. 11 where the variable power lens 152 is retracted from the finder optical path, and when the electromagnet 160 is excited, the electromagnet 160 is moved. Attracts the armature 159 against the tension spring 157, and moves the variable power lens 152 to the position R shown by the chain double-dashed line in FIG. 11 for advancing into the finder optical path, thereby expanding the viewfinder field AV.

According to the stereo visual field changing mechanism 150, the finder visual field AV which is formed smaller than the finder visual field V as shown in FIG.
Since it is possible to magnify and observe with the variable power lens 152, it is possible to make the view field of view during stereo photography easier to see.

As shown in FIG. 13, instead of the above-mentioned stereo visual field changing mechanism 150, the visual field frame 64 and the eyepiece lens 65 are provided.
A movable variable magnification lens 161 that is always located in the finder optical path between and is movable along the finder optical axis O;
The movable variable-magnification lens 161 and the eyepiece lens 65 constitute an eyepiece optical system, and the stereo adapter mounting detection unit 13
4 detects the mounting of the adapter 100, the drive mechanism 162 shown by the alternate long and short dash line is actuated to move the variable magnification lens 16
1 may be moved along the viewfinder optical axis O by a predetermined distance to enlarge the viewfinder field of view Av for observation.

When the size of the shooting screen is a panoramic size and stereo photography is performed, the aspect ratio of the shooting screen (either the left or right screen shown in FIG. 9) is close to the aspect ratio of the standard size (standard size shooting). The aspect ratio of the screen is
24: 36 = 2: 3, and the aspect ratio of the shooting screen is 13: 18≈2: 3 when the size of the shooting screen is a panoramic size and stereo photography is performed). In the above-described embodiment, the panoramic field frame 41 and the stereo field plate 141 form the viewfinder field Av in the case of stereo photography in which the size of the shooting screen is the panoramic size, and the viewfinder field Av is moved by the variable magnification lens 152 or movable. The configuration is such that the image is magnified and observed by the variable magnification lens 161, but the aspect ratio of the standard size shooting screen and the aspect ratio of the shooting screen when the size of the shooting screen is a panoramic size and stereo photography is similar. From the panoramic field frame 41, the stereo field plate 141, the variable power lens 152 or the movable variable power lens 1.
The same effect can be obtained by simply multiplying the focal length of the objective lens of the finder by a predetermined value in stereo photography without using 61 or the like. With this configuration, when the focal length of the taking lens is 35 mm, the focal length of the objective lens of the finder may be set so as to correspond to the field of view of the focal length of the taking lens of 70 mm. That is, the focal length of the objective lens of the viewfinder is
It may be set to twice the normal shooting. Some examples having this configuration will be given below.

As shown in FIG. 15, the moving lens 61 and the moving lens 62 of the finder optical system 60 are replaced by those of the photographing optical system instead of the above-mentioned stereo visual field changing mechanism 150 or the mechanism using the movable changing lens 161. The same effect can be obtained by using the finder moving lens drive mechanism 170 that is driven independently of the zoom mechanism. In this embodiment, the panoramic visual field frame 41 includes the screen size regulation plate 4
It is provided as a member different from 3, and is configured to advance into the viewfinder optical path only when the size of the photographing screen is a panoramic size and stereo photography is not performed.

This finder moving lens driving mechanism 170
Moves the moving lenses 61 and 62 back and forth in a predetermined relationship by the cam plate 173 which is moved in the arrow X direction in the drawing by the finder lens drive motor 172 via the gear train 171. A cam pin 61a and a cam pin 62a are formed on the movable lenses 61 and 62, respectively, and these cam pins 61a and 62a are attached to the cam plate 1 respectively.
73 are engaged with cam grooves 174 and 175, respectively.

A zoom code plate 176 is formed on the cam plate 173. A zoom code brush 177 fixed to a fixed portion (not shown) of the camera body 21 and connected to the finder motor drive circuit 178 slides on the zoom code plate 176, so that the finder motor drive circuit 178 is The finder magnification of can be detected. Finder motor drive circuit 1
The control means 120 connected to 78 causes the finder motor drive circuit 178 to move the movable lenses 61 and 62 in association with the change of the focal length of the photographing lens by zooming the zoom lens barrel 23 so as to obtain a predetermined finder magnification. Control.

The control circuit 120 controls the finder motor drive circuit 178 to control the finder motor drive circuit 178 when the photographing operation other than the stereo photography is performed, that is, when the stereo adapter attachment detecting unit 134 does not detect the attachment of the adapter 100. Moving lens 61,
When the stereo adapter mounting detection unit 134 detects mounting of the adapter 100, the finder motor drive circuit 1 is controlled to move 62 (normal control).
78 is controlled to move the movable lenses 61 and 62 in a state where the finder magnification at the time of the normal control is always multiplied by a predetermined magnification (preferably about 2 times as described above).
Therefore, also with this configuration, the same effect as that of the above-described stereo visual field varying mechanism 150 or the mechanism using the movable variable magnification lens 161 can be obtained.

Further, the finder moving lens driving mechanism 17
Instead of 0, as shown in FIG. 16, the adapter 100 is formed so as to project rearward (toward the camera 20) from the upper portion,
The viewfinder field multiplying member 105 may be formed integrally with the adapter 100. Also in this embodiment, the panoramic visual field frame 41 is provided as a separate member from the screen size regulation plate 43, as in the above embodiment, and is in the viewfinder optical path only when the size of the photographing screen is the panoramic size and not the stereo photography. It will be configured to advance to. In the finder visual field multiplying member 105, the variable magnification lens 106 provided in the center of the finder visual field multiplying member 105 is located in front of the finder objective window 31 of the camera 20 in a state where the adapter 100 is mounted on the camera 20. This variable power lens 106 is
This is a multiplication lens for increasing the magnification of the finder, and it is a lens for multiplying the finder magnification by a predetermined value (about 2 times). The viewfinder field multiplying member 105 includes the zoom lens barrel 23 and the fixed lens barrel 22.
It is formed at a position where it does not come into contact with the finder objective window 31 in the most stored state. Therefore, also with this configuration, the same effect as that of the above-described stereo visual field varying mechanism 150 or the mechanism using the movable variable magnification lens 161 can be obtained.

Further, by using a mechanism similar to the stereo visual field varying mechanism 150 shown in FIG.
The objective lens of the viewfinder, that is, a variable-magnification lens that makes the focal length of the movable lenses 61 and 62 a predetermined magnification (about 2 times) is replaced, and this variable-magnification lens is used before, after, or between the movable lenses 61 and 62 during stereo photography. The same effect can be obtained even with the configuration in which the finder is advanced into the optical path. Also in this embodiment, similarly to the above-mentioned embodiment, the panoramic field frame 41
Is provided as a member separate from the screen size regulation plate 43, and is configured to advance into the finder optical path only when the size of the shooting screen is a panoramic size and not stereo photography.

In the configuration according to the present invention in which the size of the photographing screen is switched to the panoramic size at the time of stereoscopic photography, the photographing field angle at the time of stereoscopic photography becomes narrower than that at the standard size. Therefore, by linking the switching of stereo photography, the strobe irradiation angle is narrowed so as to correspond to the shooting angle of view during stereo photography. The amount can substantially increase the guide number when taking a stereo photo. Some examples having this configuration will be given below.

For example, the strobe device 21 shown in FIG.
The drive mechanism 200 including 0 can narrow the irradiation angle of the strobe during stereo photography so as to correspond to the photography angle during stereo photography.
In the figure, the finder moving lens driving mechanism 170 described above is used.
The same members as are denoted by the same reference numerals. The cam plate 173 'in this embodiment further includes a cam groove 211 for strobe light formed on the cam plate 173, has a light emitting tube 212, and is supported so as to be movable in a direction parallel to the photographing optical axis. The reflector 213 can be moved via the cam pin 214 fixed to the reflector 213 and the cam groove 211. The reflector 213 is the camera body 2
It is located at a position facing the stroboscopic light emitting portion 34 inside 1. A convex Fresnel lens (not shown) for condensing the light from the arc tube 212 is fixed to a fixed portion (not shown) of the camera body 21 between the strobe light emitting portion 34 and the reflector 213. It is provided. In this embodiment, when the stereo adapter mounting detection unit 134 does not detect the mounting of the adapter 100, the control circuit 120 controls the finder motor driving circuit 178 so that the finder field of view and the illumination angle of the strobe device 210 are the shooting screen by the shooting lens. To control the moving lenses 61, 62 and the reflector 213 to move (normal control),
On the other hand, when the stereo adapter mounting detection unit 134 detects the mounting of the adapter 100, the finder motor drive circuit 178 constantly applies a predetermined magnification (about 2 times) to the finder magnification during the normal control. The moving lenses 61 and 62 are controlled to move (stereo control). By this stereo control, the irradiation angle of the strobe device 210 is always narrower (about 1/2) than the irradiation angle at the time of the above-mentioned normal control, so that the strobe light from the strobe device 210 can be effectively used, and a stereo photograph is obtained. The guide number at the time of shooting can be substantially increased.

Further, as shown in FIG. 18, the adapter 1
00, Fresnel lens 1 for narrowing the flash irradiation angle
The irradiation angle changing member 107 including 08 may be integrally provided. The Fresnel lens 108 preferably has a strobe irradiation angle of about 1/2, and the adapter 10
When 0 is attached to the camera 20, it is located in front of the strobe light emitting section 34 (on the object side). Even with this configuration, the strobe light from the strobe device 210 can be effectively used,
The guide number for stereo photography can be increased substantially.

Also, by using the irradiation angle changing mechanism (irradiation angle changing means) 220 shown in FIG. 19, the irradiation angle of the stroboscope at the time of stereo photography is narrowed so as to correspond to the shooting angle of view at the time of stereo photography. be able to. This irradiation angle changing mechanism 220 uses a mechanism substantially similar to the above-described stereo visual field changing mechanism 150, and the variable magnification lens 152 of the stereo visual field changing mechanism 150 has the irradiation angle changing mechanism 22.
At 0, it is replaced with a Fresnel lens 221 that narrows the strobe irradiation angle to about 1/2. In the figure, members that are substantially the same as those of the stereo view field varying mechanism 150 described above are denoted by the same reference numerals. Fresnel lens 221
The stereo adapter mounting detector 134 is the adapter 10.
When the attachment of 0 is detected, the strobe light emitting section 34 and the strobe light emitting section 3 provided inside the camera body 21 are provided.
When the stereo adapter attachment detection unit 134 does not detect the attachment of the adapter 100 when the stereo adapter attachment detection unit 134 does not detect the attachment of the adapter 100, the light is emitted from the stereoscopic adapter attachment detection unit 134 (position indicated by the chain double-dashed line S in the figure). It is configured to be retracted from between the reflector and the reflector. SO in the figure is a strobe optical axis extending parallel to the photographing optical axis. Even with this configuration, the strobe device 2
The strobe light from 10 can be effectively used, and the guide number at the time of stereoscopic photography can be substantially increased.

The Fresnel lens 10 in the above embodiment is used.
8 and 221 may be convex lenses.

Also, using the irradiation angle changing mechanism (irradiation angle changing means) 230 shown in FIG. 20, the irradiation angle of the strobe during stereo photography is narrowed so as to correspond to the shooting angle of view during stereo photography. be able to. The irradiation angle changing mechanism 230 includes a cam plate 2 supported so as to be movable in a direction orthogonal to the strobe optical axis SO (direction of arrow T in the drawing).
Has 31. The cam plate 231 has a switch operating section 232 exposed to the outside of the camera body 21, and is moved in the arrow T direction by a slide operation of the switch operating section 232 by the photographer. The cam plate 231 also has a cam groove 233 formed in a predetermined shape. The cam groove 233 is supported in the cam groove 233 so as to be movable in the front-rear direction along the strobe optical axis SO and has an arc tube 236. A cam pin 235 formed on the reflector 234 is fitted therein. A convex Fresnel lens (not shown) for condensing the light from the arc tube 236 is provided between the strobe light emitting section 34 and the reflector 234.
It is fixedly provided to the fixing part (not shown). With the above configuration, when the shooting screen is not the standard size stereo photo shooting, the switch operation unit 232 is positioned on the T2 side in the drawing, that is, the flash irradiation angle is the standard size shooting. When a stereoscopic image is taken in which the screen is made to correspond to the screen (normal state) and the shooting screen has a panoramic size, the switch operation unit 232 is used.
Is located on the T1 side in the drawing, and the reflector 234 is attached to the cam groove 23.
It is moved back along the profile of No. 3 to make the irradiation angle of the strobe correspond to the photographing screen of stereo photography (stereo state). The irradiation angle of the strobe in this stereo state is about 1 of the irradiation angle in the normal state.
It is preferably set to / 2. Therefore, the cam groove 233
The shape is set such that when the switch operating portion 232 is located on the T1 side in the figure, the irradiation angle of the strobe is about 1/2 of the irradiation angle in the normal state. In addition to the above configuration, if the configuration is such that the stereo photography mode is switched in conjunction with the operation of the switch operation unit 232.
The irradiation angle of the strobe in the stereo photography mode is always about 1/2 of the irradiation angle in the normal state. Therefore, also with this configuration, the stroboscopic light can be effectively used, and the guide number at the time of stereoscopic photography can be substantially increased.

Further, by using the irradiation angle changing mechanism (irradiation angle changing means) 240 shown in FIG. 21, it is possible to narrow the irradiation angle of the stroboscope at the time of stereo photography. Reflective umbrella 242 equipped with arc tube 241 facing strobe light emitting section 34
Has a Fresnel lens 243 integrally on its front part. Between the Fresnel lens 243 and the strobe light emitting section 34 provided on the front wall 21a of the camera body 21, a pair of reflection plates 244 supported so as to be able to advance and retreat in the vertical direction orthogonal to the strobe optical axis SO are provided. It is provided. Stereo adapter attachment detection unit 134 is adapter 100
In the case where the attachment of the light source is not detected, the pair of reflection plates 244 are positioned at the positions retracted from the viewfinder optical axis SO indicated by the chain double-dashed line, that is, the strobe irradiation angle is made to correspond to the standard size shooting screen. When the stereo adapter mounting detection unit 134 detects mounting of the adapter 100, the pair of reflectors 244 are positioned at positions close to the finder optical axis SO indicated by solid lines, and stereo photography is performed. The strobe irradiation angle of can be narrowed.

FIG. 22 shows the internal structure of the adapter 100. The pair of first reflection mirrors 14a and 14b are
It has rotating shafts 183 and 184 whose axes are parallel to each other and are located on the reflecting surfaces of the reflecting mirrors 14a and 14b, and is rotatable about these rotating shafts 183 and 184. The rotating shafts 183 and 184 are planes including the optical axes before and after reflection on the first reflecting mirrors 14a and 14b (see FIG. 22).
(A plane that coincides with the plane of the paper). The first reflection mirrors 14a and 14b also have rotation shafts 183 and 18
4 and the fan-shaped plates 185 and 186 which are orthogonal to each other are integrally formed. Gear portions 185a and 186a are respectively formed on the arc-shaped end portions of the fan-shaped plates 185 and 186, and these gear portions 185a and 186a are screwed with each other, whereby the pair of first reflection mirrors 14a and 1a.
4b is configured to be rotatable in a line-symmetrical relationship with respect to the photographing optical axis PO.

A small fan-shaped plate 187 is integrally formed on the fan-shaped plate 185 at a position protruding rearward of the first reflection mirror 14a. A gear portion 187a is formed at the arcuate end of the small fan plate 187, and the gear portion 187a is fixed to the fixing portion (not shown) of the adapter 100.
The drive pinion 182a of FIG.

The fan-shaped plate 185 also has a fan-shaped plate 188 that is adjacent to the small fan-shaped plate 187 and that rotates integrally with the fan-shaped plate 185. This fan-shaped plate 1
Reference numeral 88 constitutes a known photo interrupter together with the encoder 181, and therefore these fan plates 18 are provided.
8 and the encoder 181, the first reflection mirror 14a,
The rotation amount of 14b, that is, the incident angle of the first reflection mirrors 14a and 14b with respect to the second reflection mirrors 13a and 13b can be detected. Mirror drive motor 182 and encoder 181
Is connected to the mirror motor drive circuit 180 shown in FIG. 2 which is controlled by the control means 120.

The control means 120 controls the first reflecting mirrors 14a and 14b according to the photographing distance and the focal length f of the photographing lens.
Control to rotate. That is, the control means 120
Regarding the focal length f of the taking lens, as shown in FIG. 23, first and second reflection mirrors 14a (14b), 13a
The deviation angle due to (13b) is θ ₁ ; image plane (film plane) F
The distance from the optical axis PO of the taking lens to one end of the taking screen in the lateral direction is y; the first reflecting mirror 14a.
(14b) and a second reflecting mirror angle 13a (13b) forms [psi; when the subject is at _{infinity, ψ = θ 1/2 =} (1/2) tan -1 (y / 2f) ··· The first reflecting mirrors 14a and 14b so as to satisfy the equation
Is rotated (first control).

Further, the control means 120 controls the first reflecting mirror 14a of the subject light from the subject 15 with respect to the photographing distance.
If the distance U to the entrance point I to (14b) is finite, a base length L; distance U declination theta ₂ by; _{When, ψ = θ 2/2 =} (1/2) tan -1 ( L / 2U) ..., so that the first reflection mirrors 14a and 14b are satisfied.
Is rotated (second control).

Therefore, when the distance U is finite, the control means 120 simultaneously performs the above-mentioned first and second controls. That is, ψ = (1/2) [tan ⁻¹ (L / 2U) + tan ⁻¹ (y
/ 2f)] so that the first reflection mirrors 14a and 14b are satisfied.
Rotate. When the distance U is approximately ∞, the control means 12
A value of 0 performs control satisfying only the above equation.

When the reflecting mirror is a fixed type, it can be used only at a specific focal length, and if it is used at a position other than the specific focal length, the position of a pair of subject images projected on one frame of film is changed. However, there is a problem that the film is out of the center of one frame, but according to the adapter 100 of the present invention, by rotating the first reflecting mirrors 14a and 14b, stereo photography at a plurality of focal lengths becomes possible, The position of the subject image does not deviate from the center of the screen due to the change in focal length.

Further, when the reflection mirror is a fixed type,
When the subject distance changes, the incident angle of the subject light with respect to the reflection mirror changes, and the subject image moves on the image plane accordingly, which makes it difficult to stereoscopically view the finished stereo photograph using a known stereo viewer. However, according to the adapter 100 of the present invention, even if the subject distance changes, the incident angle of the subject light with respect to the reflection mirror does not change, so that the subject image does not move on the image plane due to the change of the photographing distance. .

When the adapter 100 is attached to the camera 20, the photographing optical path is extended as compared with the case where the adapter 100 is not attached.
2 is detected, the shooting distance (subject distance) OD (FIG. 24) calculated by the distance measuring unit 122 shown in FIG.
The AF / AE unit 12 provided in the camera 20 by using the correction distance MD to which the extended optical path length E is added.
1 (FIG. 2) to perform focus control. The extended optical path length E is E = e1 + e2 + e3-OD.
Therefore, MD becomes MD = OD + E. Note that e
1 is a variable, and e1 = U / cosφ.

A normal lens shutter camera having a distance measuring device is an active distance measuring device in which the distance measuring device is provided separately from the taking lens, for example, the light projecting portion and the light receiving portion are provided on the front surface of the camera body. Since it is adopted, the optical path length becomes long when the adapter is attached, and there is a problem that the extended optical path length defocuses. However, according to the above configuration, the adapter 100 is attached to the camera 20 When taking a picture, there is no focus shift due to the extension of the optical path length.

Instead of the focus control by the control means 120, when the adapter 100 is attached to the camera 20, a light receiving element located in front of the infrared light receiving portion 33 or behind the infrared light receiving portion 33 (inside the camera body 21) ( A prism (not shown) as an optical path deflecting means may be located in front of (not shown). As a specific configuration for providing this prism (optical path deflecting member),
For example, by a known means (for example, an engaging groove is formed on the front wall 21a side and an engaging pin that can be fitted into the engaging groove is formed on the prism side) on the front surface of the infrared light receiving portion 33 of the front wall 21a. The prism is detachably installed, and the adapter 10
According to the mounting of 0 on the camera 20, the photographer appropriately mounts and removes the prism by his / her own hand.

As another configuration, when the adapter 100 is mounted on the camera 20, the prism is fixedly provided on the upper surface of the adapter 100 so that the emission surface of the prism is located in front of the infrared light receiving section 33. May be As another configuration, by using a mechanism similar to the stereo visual field switching mechanism 140 and the stereo visual field scaling mechanism 150 using electromagnets shown in FIGS. 10 and 11, the adapter 100 is mounted by the stereo adapter mounting detector 134. The prism may be advanced or retracted in front of the light receiving element (not shown) inside the camera body 21 in association with the detection of attachment / detachment. Furthermore, instead of using the prism, a lens may be used.

Although the camera 20 in the above embodiment is a lens shutter camera, when the adapter 100 is attached to a single-lens reflex camera (not shown), as shown in FIG. 25, left and right images within the viewfinder field V '. Since the boundary of is unclearly recognized (NC in the figure is the part that is unclearly recognized),
In the single-lens reflex camera (not shown) according to the present invention, a field frame 190 is provided at the boundary between the left and right images in the finder field V ′ as shown in FIG. 26 in association with the mounting of the adapter 100 on the single-lens reflex camera. It can be configured. The mounting detection of the adapter 100 of the single-lens reflex camera in this configuration is similar to the above-described detection means of the camera 20 (that is, the electrical contact pin 25 of the camera 20, the adapter 100).
The same detection means as the detection means composed of the electrical contact land 112 and the stereo adapter mounting detection section 134) can be used. As a specific structure for providing the visual field frame 190, for example, the visual field frame 190 is configured as a liquid crystal display unit provided on a focusing screen (not shown), and when the mounting of the adapter 100 is detected, the liquid crystal When the mounting of the adapter is not detected by energizing the liquid crystal part to make the liquid crystal part non-transparent, the liquid crystal part is made to be transparent and transparent without energizing the liquid crystal part. Is possible.

As another specific structure for providing the visual field frame 190, a visual field formed as a rod-shaped member or the like on a focusing screen (not shown) is interlocked with attachment and detachment of the adapter 100 to and from a single-lens reflex camera. Frame 1
90 may be mechanically advanced and retracted. According to this configuration, when the adapter is attached to the single-lens reflex camera to take a picture, the boundary between the two left and right object images to be observed in the viewfinder field can be clearly recognized.

In the photograph finished by stereo photography, the boundary between two subject images projected in one frame of film is very unclear. When a photo is printed, typically the entire area of the subject filmed on the film is not printed, and only a narrow area with the edges of this entire area cut. If the printed photograph is printed in either the left-right direction or in the film running direction, the boundary between the two subject images will be displaced from the center of the photograph. If the boundary is clearly visible, the boundary can be appropriately set in a known stereo viewer, and thus it becomes easy to appropriately observe the stereoscopic image. In order to clarify the boundary between the two unclear object images in the related art, for example, a light emitting unit extending in a direction orthogonal to the traveling direction of the film at a position on the film pressure plate corresponding to the position of the boundary. In the case of stereo photography, the light emitting portion is caused to emit light after one frame of film is photographed, and the boundary between two subject images in the one frame of film can be clearly recognized.

As another method, a transparent plate is provided immediately before the film, and the position on the transparent plate corresponding to the boundary position is
A liquid crystal light-shielding portion extending in a direction orthogonal to the running direction of the film is provided so that the liquid crystal light-shielding portion is not energized except in the case of stereo photography, and the liquid crystal light-shielding portion is in a light-transmitting state. By energizing the liquid crystal light-shielding portion during shooting of one frame so that the liquid crystal light-shielding portion is in a non-light-transmitting state, the boundary between two subject images in one frame of the film can be clearly recognized.

In this embodiment, the size of the photographed screen as the horizontally long size that is switched by the screen size switching mechanism 40 is the panoramic size, but it may be a size other than the so-called high-definition size.

[0068]

As is evident from the foregoing description, according to the stereo photographing apparatus of the present invention, in the case of photographing by mounting a stereo adapter in a single-lens reflex, stereo detecting means to SLR main <br/> La when detecting the mounting of the adapter, since the boundary enhancement means to visually emphasize the boundary between the two images observed in the finder field of view of SLR camera, the boundary of the left and right two object images observed in the finder field of view Can be clearly seen.

[Brief description of drawings]

FIG. 1 is a perspective external view showing a camera and a stereo adapter to which the present invention is applied.

FIG. 2 is a diagram showing a control block of the camera.

FIG. 3 is a perspective view showing a finder optical system and a screen size switching mechanism provided in the same camera.

FIG. 4 is a front view showing a screen size switching mechanism in a state of being switched to a standard size.

FIG. 5 is a front view showing the screen size switching mechanism in a state where the screen size is switched to a panoramic size.

FIG. 6 is a perspective external view of the stereo adapter as seen from the back surface thereof.

FIG. 7 is a plan sectional view showing a connection structure between the stereo adapter and the zoom lens barrel.

FIG. 8 is a view showing a shooting screen by conventional stereo photography in which left and right images are formed as a vertically long screen.

FIG. 9 is a diagram showing a shooting screen by stereo photography in the present invention in which left and right subject images are formed as horizontally long screens.

FIG. 10 is a perspective view showing a stereo visual field switching mechanism.

FIG. 11 is a perspective view showing a stereo visual field varying mechanism.

FIG. 12 is an explanatory diagram showing a state of a viewfinder field.

FIG. 13 is a perspective view showing another embodiment of the stereo visual field varying mechanism.

FIG. 14 is a perspective external view showing a stereo adapter integrally provided with a stereo photographing visual field forming member and a camera to which the stereo adapter is attached.

FIG. 15 is a perspective view showing a finder moving lens driving mechanism.

FIG. 16 is a perspective external view showing a stereo adapter integrally provided with a variable power lens and a camera to which the stereo adapter is attached.

FIG. 17 is a perspective view showing a drive mechanism including a strobe device with a variable irradiation angle.

FIG. 18 is a perspective external view showing a stereo adapter integrally provided with an irradiation angle changing member and a camera to which the stereo adapter is attached.

FIG. 19 is a perspective view showing an embodiment of irradiation angle changing means.

FIG. 20 is a perspective view showing another embodiment of the irradiation angle changing means.

FIG. 21 is an explanatory view showing another embodiment of the irradiation angle changing means.

FIG. 22 is a top view showing the internal structure of the stereo adapter.

FIG. 23 is a diagram for explaining the positional relationship between the first reflection mirror and the second reflection mirror that are rotated according to the shooting distance and the focal length.

FIG. 24 is a diagram for explaining a state where the optical path length is extended by the stereo adapter.

[Fig. 25] Fig. 25 is a diagram showing a state of a viewfinder field in stereo photography using a conventional single-lens reflex camera.

FIG. 26 is a view showing a state of a viewfinder field by stereo photography using the single-lens reflex camera according to the present invention.

FIG. 27 is an explanatory diagram illustrating the principle of a stereo photography apparatus.

[Explanation of symbols]

13a 13b Second reflection mirror 14a 14b First reflection mirror 20 cameras 22 Fixed lens barrel 23 Zoom barrel 24 Engaging claw 25 electrical contact pins 26 cam ring 40 screen size switching mechanism 41 panoramic view frame 60 finder optical system 100 stereo adapter 102 connector 103 Light-shielding member (stereo photographing field forming member) 104 Light shield 104a opening 106 Variable magnification lens 107 Irradiation angle changing member 108 Fresnel lens 110 engagement claw 111 mount 112 electrical contact land 140 Stereo view switching mechanism 142 Light-shielding part (stereo photographing field of view forming member) 142a opening 150 Stereo field of view zooming mechanism 152 variable magnification lens 160 electromagnet 190 Field of view frame

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03B 35/00-37/06 G03B 15/00 G03B 17/18-17 / 20,17 / 36 G03B 17 / 56-17/58

Claims (5)

(57) [Claims] 1. The same subject viewed from different viewpoints
One of the image, the stereo adapter and stereo adapter for Imprint by adjacent film one frame, the stereo adapter in the stereo photography apparatus and a SLR camera mountable to the photographic lens front, the SLR camera detecting means for detecting the presence or absence of attachment of; when the detecting means detects the mounting of the stereo adapter to SLR camera, visually emphasize the boundary between the two images observed in the finder field of view of SLR camera And a boundary emphasis means for controlling the stereo photography device. 2. The stereo photography apparatus according to claim 1, wherein the boundary emphasizing unit has a liquid crystal display section provided on the focusing screen along the boundary, and the liquid crystal display section is energized to close the boundary. Stereo photography device that visually emphasizes. 3. The stereo photography apparatus according to claim 1, wherein the boundary emphasizing means causes the rod-shaped member to advance onto the focusing screen in association with the mounting of the stereo adapter. 4. A stereoscopic photography apparatus of claims 1 to 3, wherein the detection means includes a camera contact provided on the SLR camera, the adapter side contact provided in the stereo adapter in correspondence to the camera contacts to detect the presence or absence of the mounting of the stereo adapter to the SLR camera by detecting the presence or absence of the conduction of, stereo photography equipment. 5. The stereoscopic photography apparatus according to claim 4, the photographing lens front stereo adapter and SLR camera, has a connectable structure to one another via a bayonet mount having a plurality of engaging claws A stereo photography device in which the contact on the camera side and the contact on the adapter side become conductive when the stereo adapter is attached to the front end of the taking lens via this bayonet mount.