Very unique modification of two Yashica cameras into one stereo camera to shoot 3D images. The aperture width is 32mm and the film advance sequence is 1-3-1... This comes from the estate of well-known stereo photographer and collector. Seems to be working OK but have not been tested with film. David Burder writes, regarding this camera. That little Stereo Yashica was my favourite travelling camera companion for many years. Totally reliable, very compact due to its reduced lens base and pancake lenses, and with very easy to use basic, manual controls. Very basic but with wonderful results....