Yashica-635 is a double format film TLR camera made by Yashica and introduced in c.1958.
It is enhanced Yashica-D with the added ability to use 35mm film as an alternative to 120.
To use 35mm requires an adaptor kit. This feature is very useful, effectively making two great cameras in one. When shooting 120 film, the standard 80mm lends itself well for landscape or architecture but lacks focal length needed for portraits. However, when loaded with 35mm the 80mm lens is ideal for portraits.
Conversion kit includes mask assembly, pressure plate, take-up spool adapter and cartridge and adapters.
The lens is Yashikor 80mm f/3.5 in Copal-MXV shutter with speeds 1-1/500. Rewind knob for 35mm is on upper left side of the camera.
Among collectors, the 635 is more desirable than the Yashica-D and can be found for around $200.