Eclair ACL Shutter (175°)

The plane shutter. In the ACL, unlike other reflex
cameras where the mirror is also used as a shutter, a
large diameter, plane shutter having an exposure
angle of 1.750 operates in front of the film. The
shutter cuts off the image in the direction of the
smallest dimension, i.e. from top to bottom, and is so
shaped to ensure an even exposure.