French Landscape Lens HERMAGIS Opt.en Breveté s.g.d.g. Paris
Convertible Lens 1868 N°13657 HERMAGIS Opt.en Fab.t Breveté s.g.d.g. Paris
27x11,5 cm. F= 28,8 cm.
A short excerpt from "Hermagis" pag 181 :
The cap on the shutter of this lens imitates the shape used by Derogy in the Objectif à foyers multiples et lentilles addictionelles. He used the shutter cap in such a way, that when one wanted to use the landscape lens, the front part of the cap could be unscrewed and screwed instead on the front part of the landscape lens...(continue)
A short excerpt from pag 189: .....This telephoto model, shorter than the models that came before it, is mounted on a photographic objective with a Petzval design. The lenses, with a rear diameter of 4.15 cm and a front diameter of 5.3 cm., allow for an aperture of f/2.37. Fabre mentions a Harmagis teletube model in 1897 (26) for the 9x12 format. This teletube, with a center of gravity that coincided with the point of attachment and a 24 cm. draught, did not force the screws which held the lens together…above, an advertisement from 1910 with the prices of the telephoto lens....(continue)
A short excerpt from "Hermagis"
Pag 174…In 1854 the name Hermagis appears alongside Derogy’s name on a Petzval-type lens, together with the wording: Opticiens. The address is the same: 33 Quai de l’horloge. The Wallets, relatives of Derogy, had already opened an atelier in the Quai in the 1920’s. The lens is rather large, and considering the size of the lenses (13 cm.), one can assume that the opticians had already acquired quite some experience, or that they could count on very competent master craftsman to work on the lenses for them. It is possible that Derogy’s ties with the laboratory in Sully, which specialized in the production of glass for lenses, was a deciding factor. In any case, after he registered his company in 1855….(continue)