The Rolleiflex 3.5F is a medium format twin-lens reflex (TLR) camera manufactured by Franke & Heidecke (Rollei) in Germany, introduced in 1958. It uses 120 roll film to produce 6x6 cm square images. The camera is equipped with a Carl Zeiss Tessar 75mm f/3.5 lens and a Synchro-Compur leaf shutter with speeds from 1 to 1/500 second plus Bulb. Focusing is achieved via a ground glass screen viewed through the waist-level finder, and film advance is automatic with a frame counter. The 3.5T features a built-in exposure meter in later versions and supports flash synchronization. Its compact, robust design and high-quality optics made it popular among both professionals and enthusiasts.