Pellicle mirror

In photography, the pellicle mirror has been employed in single-lens reflex (SLR) cameras, at first to enable through-the-lens exposure measurement and possibly to reduce camera shake, but later most successfully to enable fast series photography, which otherwise would be slowed down by the movement of the reflex mirror, while maintaining constant finder vision.

[1] Pellicle mirrors are ideal for this purpose, even today, since they are lighter and cheaper than an optical block of dichroic prisms, which would be heavy and expensive for large, high resolution film or plates.

The object was to accomplish exposure measurement through the lens (TTL), which was pioneered by Tokyo Kogaku KK, Japan in the 1963 Topcon RE Super.

The meter cell was swung into the light-path behind the mirror by operating a lever on the right-hand camera front for stopped down exposure reading, momentarily dimming the viewfinder.

[4] The Pellix pellicle mirror was an ultra-thin (0.02 mm) Mylar film with a vapour deposited semi reflecting layer.

[5] In 1984, Canon released another version of their then "New F-1", which attained a record 14 frames per second performance, being the fastest analog SLR of that time.

With that camera light is reflexed sideways into a primary plano-convex finder lens, the plane side being partially or fully matted.

In the Soviet Union in 1970 appeared the Kiev 16 Alpha, also featuring a pellicle mirror finder system that deflects strictly vertically.