US 5,037,195 AGranted

Sound-damping lens adapter for a motion-picture camera

AssigneeClairmont Camera, Inc.

InventorsDenny Clairmont, Kenneth W. Robings

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Abstract

This adapter is interchangeable with standard nondamping lens-mounting adapters. It reduces the amount of vibration that is transmitted from the camera mechanism to the lens. It thereby reduces the amount of vibration that is retransmitted as objectionable background sound, by radiation from the lens, into a sound stage or other scene area. A vibration-absorbing resilient ring is securely fixed to two substantially rigid rings. A camera mount is secured to one of the rigid rings, for mounting to a camera in a normal position for mounting a standard adapter. A lens attachment is secured to the other rigid ring, for attachment to a lens in a normal position (on the lens) for attaching a standard adapter. The camera mount and the lens attachment both have respective standard-configuration portions, which are spaced apart by a distance that is precisely equal to a standard distance between the respective corresponding portions of a standard adapter. Hence the resilient ring absorbs a fraction of the objectionable noise vibration, deterring that fraction from being transmitted to and radiated from the lens into the scene area--but does so while maintaining a standard distance between the lens and the camera focal plane, and without modification of either the lens or the camera.

Claims23

Dependent claims

A sound-damping adapter for use in place of a standard nondamping adapter in mounting a lens to a motion-picture camera, such a camera being subject to generation of objectionable noise vibration, and such a lens being subject to transmission and radiation of such noise vibration from the camera into a scene area;

and adapter comprising:
a first substantially rigid ring;
mounting means, secured to the first ring, for mounting the first ring to such a camera, substantially outside such camera, in a normal position for mounting such a standard adapter;
said mounting means including a portion that has a standard configuration of such a standard adapter for such mounting;
a second substantially rigid ring;
attachment means, secured to the second ring, for attaching the second ring to such a lens, in a normal position for attachment of such a standard adapter;
said attachment means including a portion that has a standard configuration of such a standard adapter for such attachment;
a vibration-absorbing resilient ring securely fixed to the first and second rings and deterring transmission of vibration from the first ring to the second ring;
the respective standard-configuration portions of the mounting and attachment means being spaced apart by a distance that is precisely equal to a standard distance between the respective corresponding portions of such a standard adapter;
wherein in operation the resilient ring absorbs a fraction of such objectionable noise vibration, deterring such fraction from being transmitted from the normal standard-adapter mounting position to such lens, and from being radiated from such lens into such scene area, but while maintaining a standard distance between such lens and such camera focal plane and without requiring any modification of either such lens or such camera.

7 more elements

A low-noise cinematographic system comprising:

a substantially conventional motion-picture camera that is subject to generation of objectionable noise vibration, and that has a substantially conventional built-in sound-damping assembly for attachment of lenses;
the built-in assembly including a block that has a lens-receiving fitting and is secured to a resilient vibration absorber, for reducing transmission of the camera-generated vibration to such lenses;
a sound-damping adapter, substantially outside the camera, mounted to the lens-receiving fitting of the built-in sound-damping assembly so that the assembly and the adapter together form a multiplicative two-stage filter for noise vibration;
and
a substantially conventional lens, mounted to the sound-damping adapter, that radiates a portion of noise vibration which reaches the lens;
whereby in operation the multiplicative vibration filter formed by the assembly and adapter together minimizes the amount of such noise vibration from the camera that reaches the lens, and so minimizes the amount of vibration radiated by the lens.

3 more elements

Dependencies are inferred from the claim text.