B&L Iris Diaphragm Shutter

Bausch & Lomb Iris Diaphragm shutter with Bausch & Lomb lens image by Luis Cozeto (Image rights)

The Iris Diaphragm Shutter of 1891 was the first of Bausch & Lombs characteristic series of two-piston multi-speed brass shutters with iris diaphragm for standard camera lenses. It had a shutter speed setting device on top that reminds of a clock or a ship's machine telegraph. The predecessing version of 1888, invented by Edward Bausch, had only one piston for remote shutter release tube connection, and no shutter speed setting scale.