Aside from the film gauge selection – 8 mm (amateur), 16 mm (semi-professional), 35 mm (professional) and 65 mm (epic photography, rarely used except in special event venues) – the cinematographer has a selection of stocks in reversal (which, when developed, create a positive image) and negative formats along with a wide range of film speeds (varying sensitivity to light) from ISO 50 (slow, least sensitive to light) to 800 (very fast, extremely sensitive to light) and differing response to color (low saturation, high saturation) and contrast (varying levels between pure black (no exposure) and pure white (complete overexposure).