Stereoscope ‚Foyer Long pour Filmcolors‘

This Mat­tey stere­o­scope is a long-focus view­er designed for the obser­va­tion of colour trans­paren­cies. Its longer focal length reduced image mag­ni­fi­ca­tion, mak­ing the grain of ear­ly colour pho­tographs less notice­able than when viewed through a con­ven­tion­al stereoscope.
A large tilt­ing mir­ror at the rear pro­vides illu­mi­na­tion for view­ing glass trans­paren­cies or mount­ed colour slides. As the stere­o­scope lacks the hinged top flap found on many hand-held view­ers, it is not intend­ed for paper stereoviews.
The inter­pupil­lary dis­tance scale is char­ac­ter­is­tic of Mat­tey stere­o­scopes pro­duced dur­ing the 1930s. The 1936 cat­a­logue describes this type as Foy­er Long pour Film­col­ors. By 1927 it was described as Foy­er Long pour Autochromes, indi­cat­ing its use with Autochrome plates. The mod­el did not yet appear in Mat­tey’s 1915 catalogue. 

Fur­ther read­ing: Stere­oscopy His­to­ry Series — Mat­tey (A. Ruiter)