|Conley Long Focus Model XV plate camera|
with plate-holders (dark slides)
image by Inspiredphotos (Image rights)
A plate camera is one whose light-sensitive elements are single pieces of glass coated with light-sensitive chemicals, or, later, single pieces of film, each one taking one photo.
The earliest of cameras were loaded in this single-shot manner - and had to be loaded in the dark. Later cameras could be loaded using a plate holder (a dark slide) - a box containing the plate which could be fitted into the camera, then the side of the slide facing the lens could be opened for the exposure, and closed for the slide's removal. This way cameras could be loaded away from the darkroom, and photographers could carry slides for more than one exposure. Many early plate cameras, and later large format cameras, are focused and the photo composed on a ground glass screen, fitted into the plate position. When the camera is focused and pointing in the right direction, the focus screen is replaced by the plate, and the exposure made.
Attempts were made to automate plate loading, resulting in magazine cameras containing a number of plates and a mechanism for using each in turn.
|Western Cyclone Jr., 1899|
showing plate-holder and storage compartment
image by PhotoShop Guru (Image rights)
|English ¼-plate Victo camera with wooden plate-holders c.1898|
image by Geoff Harrisson (Image rights)