Topcon was the second full system 35mm camera, came out in 1966s. The SuperRE had options for interchangeable focusing screens, finders, had motor drive and a winder, bellows, and pretty wide selection of lens. It used the same mount aUsed T the Exacta but now sure if old Exacta lens could be used. Nikon had a much wider selection of lens including very fast primes Like Nikon had the Nikormate Topcon had the RE as a basic body. The U.S Navy used the SuperDM until Topcon left the market in 1977 or so. The big advantage of the Topcon SuperRE and later SuperDM the meter was built into body, so when changing to a wasit level or sports finder metering was maintained.