Microfilm camera modifiable as microfilm projector - realised by making film locating plate interchangeable with condenser lens

摘要

When the instrument is used as a camera, a locating plate holds down the film or slide coming from the cassette while the photographic exposure is made through the. The exposed film passes to a developer and on out of the camera. When the device operates as a projector, the locating plate is removed and a condenser lens is set in its place. A lamp inside the camera is switched on to provide the necessary illumination. The condenser lens has no shutter. The same lens is used as for photography, and the microfilm image is projected on to the table which, at other times, holds the original to be copied.