Lancaster's patent pocket camera was the subject of British patent number 12,571 of 4 October 1886. The camera first appeared in a commercial form in 1886 and from 1887 two sizes were sold. These corresonded to mens and ladies watches giving negatives of 2 x 1½ inches and 1½ x 1 inch respectively. The early models had simple rotary shutters which were turned by hand, these were replaced in 1890 by an Improved-pattern camera with a simple drop shutter. The Lancaster watch camera had disappeared from the British Journal Photographic Almanac by 1896.