The Photosphere 1 is a late 19th-century French detective camera produced by Compagnie Francaise de Photographie, taking 13x18cm plates. It is notable for its hemispherical lens housing and spring-driven sector shutter, a distinctive design within the early plate-camera market.

With only a single recorded UK auction result in our dataset — a £5,208 hammer price from 2003 — the Photosphere 1 (13x18) sits firmly in the specialist collector tier rather than the general user market. Today it is rarely offered, and the limited evidence suggests four-figure values at saleroom level when an example does appear, though a single historic data point cannot define a reliable current price band. Buyers researching what one is worth or how much it sells for should treat the figure as indicative only and watch for fresh comparable sales.