DE3436886A1 - Panoramic shift adaptor for lenses - Google Patents

Abstract

The present invention relates, in accordance with the preamble of Claim 1, to a photographic adaptor for film or video use by means of which lenses can be mounted in front of camera housings so as to be displaceable transverse to the optical axis. The purpose of the design consists in adapting lenses provided for larger image formats, for example from half-plate mirror reflex cameras or whole-plate cameras, to camera housings of smaller formats, for example to miniature cameras of 24 x 36 mm so as to be capable of displacement as 90 DEG transverse to the optical axis.

Description

Panorama shift adapter for lenses

The present invention relates to the preamble of the claim 1 a photographic, film or video technical adapter through which lenses can be mounted in front of camera housings as displaceable transversely to the optical axis.

The purpose of the construction is for larger image formats created lenses, for example from medium format mirror reflex or large format cameras on camera housings of smaller formats, for example on 35mm cameras 24x36mm than 900 to adapt transversely to the optical axis.

Lenses of the types mentioned draw over a larger image circle and usually have an infinite, higher focal length or a longer flange focal length than usual created for smaller image formats Lenses.

The invention uses these different circumstances with one Adapter without modification, generic lenses using the appropriate adapter bayonet shapes on corresponding camera housings smaller image formats than up to infinity To be attached sharply defined and at the same time displaceable to the optical axis.

According to the state of the art, lenses are known from several manufacturers with built-in adjustment mechanism or cameras mainly from the large format with built-in adjustment mechanism primarily for the purpose of perspective Compensate for falling lines.

The inventive design of the adapter according to claim 1 brings a number of advantages which together with further details and inventive features illustrated for example from the description below.

An adapter according to the invention enables relative displacement short focal length lenses of the aforementioned types on camera housings of smaller formats, for example an f = 50mm lens which is for a 6x6 cm reflex camera is calculated, with the advantage that it compensates for perspective distortions of the image, for example the erection of falling lines, which images vertical edges of the subject are, can be made. Regarding this Suitable lens focal lengths of the aforementioned type are currently available from f = 35mm to f = 60r, lm from different manufacturers. That, by means of the adapter The possible displacement path of such lenses is at least 20 mm from the optical one Axis in front of, for example, single-lens reflex cameras of the format 24x36mm with good recording results. Advantages over the prior art according to so-called PC or shift lenses usual focal lengths f = 28mm and f = 35mm with a permanently integrated shift mechanism consist in the fact that such lenses are relatively expensive according to their current state Require construction, but can still only be moved up to about 11mm from their optical axis are. With the adapter-compliant use of, for example, an f = 35mm wide-angle lens for a 4.5x6cm single lens reflex camera, on the other hand, the generally applicable optical Due to the larger adjustment range, rules have a significantly increased efficiency the perspective compensation of falling Lines scored. In addition, the adapter according to the invention provides this possibility of the perspective Compensation with generic lenses even with longer focal lengths, for example with an f = 50mm of a 6x6 reflex camera, with sufficient local space available, because of the more beautiful image perspective compared to the short focal length ones, which have a disadvantageous effect here f = 28mm and f = 35mm PC or shift lenses.

These achievable advantages can be used to compensate for falling lines by the rotatable design of an adapter according to claim 3 with the advantage continued that, in addition to the vertical, also a compensation of the horizontal Perspective distortion is caused, which for example is part of the horizontal Are lines of an image when viewed sideways from the subject.

A better recording design is achieved, for example, by the inventive Adapter achieved on the one hand for architectural photography in the format 24x36mm.

A shift out of the optical axis of all with the recording camera associated lens focal lengths of the aforementioned type also causes panorama effects by means of several recording processes with still and motion picture cameras.

With the adapter on which the registration is based, several Different recording processes for each lens with the same focal length shifted several times Image fields are recorded. The perspective lines of these image fields fit at the inner edges of the picture bl.

exactly together by trimming, because the camera housing remains immobile and only the generic lens is moved via the adapter. The thereby achievable panorama effect experiences its greatest effect when the generic Lens is shifted by half the image format via the adapter. For example 18mm offset on a reflex camera of the format 24x36mm for two recording processes, with a lens with a focal length of f = 50mm shifted by 1800, an angle of view of 2x470 per format diagonal recorded. That desptcÄ't about de.l B Actel of a lens with a focal length of f = 2lmm, which can be used without the adapter on a 24x36mm Camera get used with only one recording process according to the prior art would. The angle of view can be adjusted with the adapter and a lens of the generic type double recording process, following the previous example up to double the format according to the format length (at 2x18mm offset). The one for panorama effects The achievable advantage lies in the image structure, since the part that is important for the image is shown larger can be, but at the same time an oversized foreground and z. B. Avoided Heaven will. Furthermore, the use of a larger camera, for example the format 6x7cm, or the known disadvantages of an enlargement of a section from a single shot, for example, from the 24x36mm format, should be avoided.

Local conditions can also be an obstacle in the image structure be cut out accordingly by moving the lens.

According to the state of the art, perspective undistorted image connections would be also with the aforementioned PC or shift lenses with built-in adjustment mechanism makeable. Disadvantageous compared to the adapter method according to the invention with generic Lenses is then, on the one hand, that a l8mm adjustment path is not available, which thus has a large image overlap and that the lens offer with built-in adjustment to two or three relatively short and sometimes very expensive focal lengths are limited.

So-called panorama heads with markings are also state of the art in order to obtain image arrays for one exposure after turning the camera. The disadvantage here is that the camera has to be moved and especially with close-up subjects no undistorted perspective of the sequence of images is possible.

There are also different constructions of panorama cameras known with built-in mostly very wide-angled optics. Their construction principles however, generally differ from the adapter method according to the invention.

The advantages for the panorama effects that can be achieved with the adapter are mainly with landscape shots and that on a wide range of focal lengths can be accessed by lenses.

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Claims (10)

Claims: 1. Photographic, film and video technical adapter for attaching lenses to camera housings d.g.d., via a sliding plate (l) das Lens-side Bayow nice (4) with interchangeable lenses attached, opposite the camera-side bayonet (3) with the detachable camera housing across the optical axis of the lens (direction A) can be shifted against each other. 2. Adapter according to claim 1 d.g.d., these shifts via a threaded lock (2) can be made in quick or fine adjustment. 3. Adapter according to claim 1 and 2 d.g.d., the camera-side bayonet (3) is rotatable in the optical axis by 3600 with respect to the sliding plate (1). 4. Adapter according to claim 1 to 3 d.g.d., this via a tripod mounting thread (5) has. S. adapter according to claim 1 with threaded lock according to claim 2 d.g.d., the threaded lock (2) is rotatable in its axis or eccentrically to this, so that a rocking movement for the purpose of claims 6 and 7 is made possible. 6. Adapter according to claim 1 with threaded lock-.lactl claim 2 and 5 d.g.d., the threaded lock 2 with loop spring (6) automatically or with a detent Frictional connection between the threaded rod (7) and threaded lock (2) for the purpose of fine adjustment of the lens bayonet (4) in relation to the camera bayonet (3) in direction A. 7. Adapter according to claim 1 with a threaded lock according to claim 2.5 and 6 d.g.d., the threaded lock (2) via a recess in the axis of the threaded rod (7) has, which when rocking rotation of the thread lock the frictional connection between the thread lock (2) according to claim 6 for the purpose of rapid displacement of the lens bayonet (4) opposite the camera bayonet (3) in direction A. 8. Adapter according to claim 1 to 7 d.g.d., a bearing ring (8) rigid and raised to the sliding plate (1) is connected. 9. Adapter according to claim 1 to 8 d.g.d., the bearing ring (8) a in the direction of the camera bayonet part (3) having increasing outer cone diameter to to cause automatically attractive force for claim 10. 10. Adapter according to claim 1 to 9 d.g.d., the storage for rotation according to claim 3 by balls (9), which happens via at least three pieces of adjusting screws (10) with a so-called cutting tip (internal countersink) on the cone of the bearing ring (8) radial rotatable bearing between the camera bayonet part (3) and the one on the sliding plate (1) effect flanged bearing ring (8).