Focal Plane Shutter

Shutter comprising one or more roller blinds of fabric or metal, having a variable slit which moves across the back of the camera when the release is pressed and exposes the film progressively. This type of shutter is mounted as close as possible to the surface of the film—i.e., to the focal plane. In that position it is most efficient and also gives consistent exposures with lenses of varying focal lengths. William England invented the focal plane shutter in 1861, re-introduced by B. J. Edwards, 1879, and included in the camera patented by Ottomar Anschutz in 1888, to whom its invention is usually erroneously attributed.