The Sixtar 2 is a selenium light meter used to measure light for correct exposure in film photography. It does not use batteries — the selenium cell generates electricity from light. Very popular in the 1960s–1970s. Specifications Type: Analog exposure meter Power: No battery (selenium cell) For: 35mm, medium format, large format film cameras Measures: Ambient light (reflected light) ISO range: approx. 6 – 1600 Shutter scale: full mechanical calculator dial Made in Germany How It Works Point it toward your subject. Needle moves according to light level. Turn the outer dial to align the needle value. Read matching combinations of: Shutter speed Aperture (f-stop) Classic mechanical exposure calculator system.