Adapter for coupling a photographic camera with a viewing device

Claim 1

An adapter for use with a photographic camera to join the camera to the proximal end of an optical viewing device such as an endoscope so that the image of an object formed by the viewing device can be viewed and photographed simultaneously wherein the camera is of the type which has a photographic objective lens focused at infinity and a reflex viewing system which has an entrance pupil that occupies only a portion of the entrance pupil of the camera taking lens and has a central axis which is laterally offset with respect to the optical axis of the camera taking lens and wherein the viewing device is of the type which has an eyepiece located at its proximal end for forming a collimated to nearly collimated object image which is visible through an exit pupil spaced behind the eyepiece wherein the angular field of the object image formed by the eyepiece at the exit pupil is smaller than the angular field of view of the camera taking lens and viewing system, said adapter comprising: a coupling for positioning the viewing device in light-tight relation to the camera, said coupling having one end adapted for attachment to the camera and another end which has a central axis and which is adapted to releasably receive and position the viewing device eyepiece so that the optical axis of the viewing device exit pupil is collinear with said central axis of said other end, and further configured and arranged so that, when said viewing device eyepiece is connected with said coupling other end and said coupling one end is attached to the camera, the optical axis of the viewing device exit pupil is always aligned at a predetermined point along a line passing through the center of the camera taking lens and viewing system entrance pupils, said coupling structured in the foregoing manner operating to preclude vignetting of the camera viewing system entrance pupil by aligning the optical axis of the viewing device exit pupil closer to the central axis of the camera viewing system entrance pupil thereby making more image forming light from the viewing device eyepiece available for entrance into the camera viewing system than would otherwise enter the camera viewing system absent said coupling.