RU1788500C - Two-lens stereo motion-picture camera optic system - Google Patents

Abstract

Usage: the invention relates to film technology, and in particular to optical systems for movie cameras for shooting stereoscopic films. SUMMARY OF THE INVENTION: the device comprises two light separators, one of which is located on the apparatus body, and the second on the fixed part of the stereo lens frame, has a transverse part 7 located in close proximity to the obturator and parallel to its plane. The separator 6, mounted on the fixed part of the frame of the stereo lens, has a transverse part 7. located in the immediate vicinity of the shutter and parallel to its plane. When moving the movable part of a stereo lens with lenses along the optical axis during focusing or when moving the lens when converting lenses, the arrangement of light beams changes. However, the stationary position of the light dividers 6, 7 and 8 provides a guaranteed lock for the rays passing from the lens into the adjacent frame. 3 ill. Ј

Description

The invention relates to film technology, in particular to stereoscopic cinema, and in particular, relates to an optical system of a bi-objective stereo filming apparatus, which makes it possible to obtain a stereo pair on a single film.

Known stereo movie cameras with interchangeable stereo lenses. The frame of each stereo lens consists of a fixed part, rigidly fixed to the apparatus body, and a movable part with two lenses housed in it, mutually moving in a horizontal plane perpendicular to the axis of the survey. To ensure light separation

shooting channels, i.e., eliminating spurious illumination of a stereo pair frame by the peripheral part of the light beam formed by an adjacent lens, two light separators are mounted between the lens and the jumper of the frame frame of the film channel in the optical system of the known film camera frame. Between the dividers there is a zone for the passage of the mirror shutter. The front light splitter has a T-section, with the cross section of the splitter placed near the obturator parallel to the plane of the obturator mirror. Configuration

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the transverse part is selected in such a way as to ensure the maximum possible light separation of the channels when shooting with any of the interchangeable lenses. However, complete light separation is ensured by the use of external light-shielding devices with the installation of interchangeable cassettes with rigid window sizes for each stereo lens and each combination of a stereo lens with a prism attachment, which changes the basis of the survey.

A disadvantage of the known optical system is the inconvenience of operation, since it is necessary to have special external cassettes for each of the interchangeable lenses, since both separators are both mounted on the apparatus body.

The closest in technical essence to the proposed device is the optical system of a two-lens stereo filming apparatus, comprising a replaceable stereo lens, the frame of which consists of a fixed relative body of the apparatus of the part and a movable part with two lenses housed in it. In the optical system, two light separators are installed between the stereo lens and the jumper of the frame frame of the film channel. One separator (rear) is mounted on the device and is made in the form of a plate placed between the obturator and the jumper of the frame frame of the film channel. The second separator (front) is rigidly connected to the movable part of the interchangeable stereo lens, placed between the lens and the shutter and has a T-shaped cross-section, the transverse part of which is parallel to the plane of the shutter. When moving the movable part of the stereo lens (when focusing on the sharpness of the lenses), the front separator shifts and the free zone between the separators changes, which does not allow reliable light separation of channels without the use of cigarettes in the entire range of lens movement during convergence. Although the need to use cassettes remains, the dimensions of the windows of the cassettes are less critical.

Thus, the presence of only separators in the known device does not exclude the possibility of spurious illumination, and therefore, a sufficiently high quality of the obtained stereoscopic image cannot be ensured. In addition, the need to use additional external light-protective devices creates inconvenience to the operator, and also reduces labor productivity.

The purpose of the invention is to improve the quality of the resulting stereoscopic image.

The goal is achieved in that

in the optical system of a two-lens stereo filming apparatus containing a replaceable stereo lens, the frame of which consists of a part stationary relative to the apparatus body and a movable part with

0 two lenses placed in it, and two light separators, the front of which is located between the stereo lens and the shutter and has a T-shaped cross-section, the transverse part of which is parallel to the plane of the shutter, and the rear is made in the form of a plate and placed between the shutter and the personnel jumper frame of the film channel, the front splitter is rigidly connected to the fixed part of the frame of the stereo lens, and its transverse part is located in close proximity to the plane of the shutter.

In FIG. 1 schematically shows the proposed device (in a perspective view); on the

5 of FIG. 2 shows the principle of operation of the device when extending the lens when focusing at short distances (horizontal section passing through the optical axis of the lens); in FIG. 3 shows the principle

0 operation of the device when moving the lenses to each other during conversion (horizontal section passing through the optical axis of the lenses). -On the case of the stereo film-shooting device 5 (not shown), a removable stereo-film-shooting lens is installed, the frame of which consists of a part 1 that is stationary relative to the apparatus body and a movable part 2 with two identical lenses 3 and 4 housed in it. Moving the movable part 2 with lenses 3 and 4 along their optical axes provides simultaneous focusing of a pair of lenses, and the mutual movement of the lenses 4

5 and 3 in the direction perpendicular to the optical axis provides convergence (changing the center-to-center distance between lenses 3 and 4 with respect to the center-to-center distance of frame windows

0 frame 5 of the film channel). On the fixed part 1. of the frame of the stereo lens mounted front light separator 6, having a T-shaped section. The transverse part 7 of the front splitter 6 is located 5 near the plane of the shutter 9 (see Figs. 2 and 3) and parallel to the plane of the shutter 9. The rear splitter 8 is rigidly connected to the body of the device (not shown) and placed between the shutter 9 and the jumper of the frame frame 5 .

The device operates as follows (Fig. 2 and 3).

In stereo filming, each of the lenses 3 and 4 forms a light beam, forming respectively the left and right floor of the images, slightly larger than the frame windows, due to the need for lateral movement of the lenses 3 and 4 with respect to the centers of the frame windows. The peripheral parts of the light beams directed towards adjacent frames and being parasitic for them are overlapped by light dividers 6, 7, 8.

When moving the moving part of the stereo lens, i.e. the movable part of the mount with lenses 3 and 4 along the optical axis when focusing (Fig. 2) or when moving the lenses 3 and 4 relative to each other inside the movable part of the mount of the stereo lens when converging the lenses (Fig. 3), the position of the light beams changes slightly. However, the stationary position of the light separators 6, 7, 8 provides a guaranteed lock for the rays passing from the lens into the adjacent frame. When a stereo lens is changed, this guaranteed lock is retained, since the separator is mounted on the fixed part of the frame of the interchangeable stereo lens and is an integral part thereof.

The dimensions and shapes of the transverse part 7 of the front splitter 6 are different depending on the type of stereo movie camera and on the magnitude of the focal length of the lens. For movie cameras with a mirror shutter, this transverse part 7 of the front splitter b is in the form of a trapezoid, for machines with a disk shutter, it is rectangular.

Thus, the proposed optics system eliminates the possibility of cross-illumination of the neighboring frame as

left and right lenses without the use of additional light protection devices, for example, a cough, since the front splitter is located on the fixed part of the stereo lens barrel, and this ensures a constant clearance for the shutter of the film camera, and together with the rear splitter, a guaranteed lock for the rays is provided, passing from the lens into an adjacent frame of a stereo pair. Since the guaranteed lock is retained when using any stereo lens from the line, the operator is freed from the additional operation of installing the cassettes in the light protection device, which facilitates the operator's work. At the same time, ensuring reliable light separation improves the quality of the footage due to the complete elimination of rejects by mutual illumination, which improves the quality of the obtained stereoscopic image.

Claims (1)

SUMMARY OF THE INVENTION An optical system for a two-lens stereo filming apparatus, comprising a replaceable stereo lens, the frame of which consists of a part that is stationary relative to the apparatus body and a movable part with two lenses housed therein, and two light spacers, the front of which is located between the stereo lens and the obturator and has a T- shaped section, the transverse part of which is parallel to the plane of the obturator, and the rear is made in the form of a plate and placed between the obturator and the jumper of the frame frame fi the lm canal, characterized in that. that, in order to improve the quality of the obtained stereoscopic image, the front splitter is rigidly connected to the fixed part of the frame of the stereo lens. and its transverse part is located in close proximity to the plane of the shutter.