Focusing Aid for Copying Camera : Jacob Rabinow

Focusing Aid for Copying Camera
ca. 1993

For optimal results, photographers need to focus on bright and well-defined objects. Documents being photographed often are neither. Rabinow invented an aid to help solve this problem. A mirror at an angle of 45° to the horizontal and an incandescent filament are mounted on a device that rests on the surface to be photographed. The distance from the filament to a point on the mirror equals the distance from that point to the document. By focusing the camera from the same distance on the image of the filament that appears in the mirror, the camera will be correctly focused on the document when the device is removed and the camera is placed at this distance from it. Rabinow shares this patent with his wife, Gladys Rabinow, who stimulated his thinking with regard to an approach to the problem.