Abstract: A camera shutter and focus encoder assembly comprises an encoder mask fixed in a camera housing and having an arcuate window having alternating opaque and transmissive portions, and an encoder sheet mounted in the housing in abutting relationship with the encoder mask, the encoder sheet being movable with exposure blades and the focus lens of the camera and having an arcuate window having alternating opaque and transmissive portions therein. Means are provided for pressing the encoder mask and the encoder sheet together with the mask and sheet windows in registration with each other. A sensor passes pulses of light through the mask and sheet windows when the transmissive portions thereof are in registration and detects the pulses of light, converts the light pulses to electrical signals, and transmits the electrical signals.