The Mentor Reflex was an old style single lens reflex camera for film plates or sheets, made by Goltz & Breutmann. It was available for several film formats: 10x15, 13x18, 13x18, 18x24, 6.5x9, 6x9, 9x12, 9x9. A two-shutter variant was available. It had the typical foldable high leather hood over the reflex viewfinder matte screen. Its bellows wasn't just movable forward and backward for focusing. A variety of lens board movements was possible.

A typical shutter equipment of such a camera was a focal plane shutter with speeds 1/8-1/1300 sec.

Typical lens equipment was a Zeiss Tessar 4.5/135mm (for 9x12cm format), a Meyer Helioplan Double Anastigmat f/4.5 4¼ inch or a Zeiss Tessar 4.5/12cm (for 6x9cm format).