Shutter Speed - Cinematographic Shutter Formula

Cinematographic Shutter Formula

Motion picture cameras used in traditional film cinematography employ a mechanical rotating shutter. The shutter rotation is synchronized with film being pulled through the gate, hence shutter speed is a function of the frame rate and shutter angle.

Where E = shutter speed (reciprocal of exposure time in seconds), F = frames per second, and S = shutter angle:

, for E in reciprocal seconds

With a traditional shutter angle of 180°, film is exposed for 1/48 second at 24 frame/s. To avoid effect of light interference when shooting under artificial lights or when shooting television screens and computer monitors, 1/50 s (172.8°) or 1/60 s (144°) shutter is often used.

Electronic video cameras do not have mechanical shutters and allow setting shutter speed directly in time units. Professional video cameras often allow selecting shutter speed in terms of shutter angle instead of time units, especially those that are capable of overcranking or undercranking.