Film Cameras
The 35 mm format, or simply 35 mm, is the common name for the 36x24 mm film format or image sensor format used in photography. It has an aspect ratio of 3:2, and a diagonal measurement of approximately 43 mm.
Medium Format
The size of the imaging sensor comes into play in the final quality of the photo. I'd rather have a 20 megapixel medium format camera than a 30 megapixel 35mm based DSLR because the physical sensor is much larger. The larger sensor the higher the quality.
