The Yashica 635 is a twin-lens reflex camera introduced by Yashica in 1958 and produced until the early 1970s as a significant export model. This double-format TLR is uniquely capable of shooting both 6x6cm images on 120 film (providing twelve frames per roll) and 35mm photographs using an adapter kit, earning its 635 designation from these dual format capabilities. The camera features a Yashikor 1:3.5 f=80mm lens with a Copal MXV shutter offering speeds from 1 second to 1/500 second and aperture settings from f/3.5 to f/22. Like most TLR cameras, it operates with waist-level viewing through a focusing screen with an optional magnifying glass for precise focus, and includes a sports finder for alternative composition. The camera lacks an integral light meter, requiring external metering or estimation techniques for proper exposure. Early 1958 models can be identified by the oval Yashica branding between the lenses, which was later changed to bold block letters in subsequent production runs.