Mamiya M645 1000s

The Mamiya M645, first appearing in 1975, is the first series of 4.5×6 SLRs made by Mamiya. It has an electronic focal plane shutter. There are two shutter release buttons on the camera body. It has a knob advance with a flip out crank and shutter speeds from 8s to 1/500. The M645 1000S (1976) adds the 1/1000 top speed, a self-timer, and a depth of field preview button. (Camera-wiki.org)