This is a copying camera consisting of a bed with a central lens standard and interchangeable standards of various formats for the original (what is to be copied) and copy.

This example has 10" x 8" standards for the original negative and the copy negative. With reducing frames this will allow copies to be made from various size originals, enlargements of the centre portion could also be made or reduction onto smaller negatives were possible.

A second 'original' standard could be used, into this a sliding back for stereo negatives was fitted. The back can slide vertically in the standard to position a particular part of the original. A holder for stereo negatives is contained in the back and able to slide horizontally, adjustment screws are present to fix the movement.

Another 'copy' standard carrying a sliding back could be attached. This carries a focusing screen. A negative holder for stereo images would have been fitted but is now missing. This allowed stereo negatives to be copied/transposed or portions of the original could be enlarged. Lantern slides could also be produced.

In the F.J. Cox catalogue of 1873 a similar camera is described as "for reducing or enlarging negatives or for producing transparencies on ground glass or opal glass". The description is of a camera with bellows though the accompanying woodcut shows an earlier sliding box arrangement.