The Bronica S2, released in 1965, was a 6x6 focal plane SLR that succeeded the Bronica S and introduced a key innovation: a removable helical focusing mount that could accommodate lenses from 40mm to 200mm. The camera featured a vertical-traveling cloth focal plane shutter with speeds from 1 to 1/1000s, supported both 120 and 220 roll film through an improved film back design, and operated entirely mechanically without requiring batteries. The S2A revision in 1969 maintained identical specifications but improved the film advance gear mechanism to reduce jamming issues and featured a smaller advance dial. Both models were typically bundled with the 75mm f/2.8 Nikkor P lens and offered chrome or black finishes, continuing production until 1977 when they were superseded by the electronic Bronica EC series.