(under subclass 208) Subject matter in which the shutter includes means to alter the light rather than, or in addition, to completely block the passage of the light.
SEE OR SEARCH CLASS
355, Photocopying,
125+, for vignetters, per se, and adapted for use in photos:graphic contact printing.
359, Optics: Systems (Including Communication) and Elements,
885+, for optical filters. 396, Photography,
545, for vignetters used with still cameras.
399, Electrophotography,
9+, for diagnostics, subclasses 38+ for controls, and subclasses 177+ for exposure.
