Giroux 'Autosynoptomètre'

Very early (if not the first) stereoscope used in orthoptic training built by Alphonse Giroux in Paris, engraved on top ‘Autosynotométre du Dr. Armaniac’. The basic principle of the so called synoptophore is still used in ophthalmology today. It is a modified form of Wheatstone stereoscope used to identify the exact point when two separately displayed images melt into one three dimensional impression. The test-images are mounted left and right of the oculars and viewed through hinged mirrors. The position of each mirror can be adjusted individually with a lever on the outside and there is an indicator scale in degrees. Very likely this viewer is the only stereoscope ever built by Giroux. A unique item in perfect condition made by one of the pioneers of photography.