Stereoscope ‚à sphères parallèles‘

Details

The Stéréo­scope à sphère par­al­lèle is a Brew­ster-type stere­o­scope. The patent describes an improved opti­cal design based on par­al­lel spher­i­cal lens­es and makes four prin­ci­pal claims: reduced image dis­tor­tion, dimin­ished chro­mat­ic aber­ra­tion (col­or fring­ing), increased mag­ni­fi­ca­tion, and reduced eye strain.
(from: Com­pendi­um of Stereoscopes)

Historical Context

Her­magis is one of France’s old­est opti­cal man­u­fac­tur­ers. In 1855, Hyacinthe Her­magis estab­lished his own opti­cal work­shop in Paris. The busi­ness was con­tin­ued in 1864 by his son-in-law, Jules Fleury, who adopt­ed the name Fleury-Her­magis. The com­pa­ny’s prod­ucts were sub­se­quent­ly mar­ket­ed under the name J. F. Hermagis.
Her­magis devel­oped into one of France’s lead­ing opti­cal firms and became par­tic­u­lar­ly renowned for pro­duc­ing high-qual­i­ty pho­to­graph­ic lens­es. By 1916, the com­pa­ny announced in its adver­tis­ing that it had already sup­plied 50,000 por­trait lens­es. In addi­tion to lens­es, Her­magis man­u­fac­tured cam­eras and stereo cam­eras, and designed the Stéréo­scope à sphère par­al­lèle, a stere­o­scope fea­tur­ing improved opti­cal performance.
In 1934, Her­magis was acquired by SOM Berthiot. Fol­low­ing the acqui­si­tion, the Her­magis name con­tin­ued to be used as a trade­mark until after the Sec­ond World War.
(from: Com­pendi­um of Stereoscopes)

Date Made

c. 1858

Place Made

Period

Manufacturer

Her­magis

Format

Related Patent

FR 34862 (H. Her­magis, 1857)
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