Shutter Angle Calculator

Cinema cameras traditionally describe exposure time as a shutter angle (borrowed from rotating-disc film shutters) rather than a fraction of a second. The relationship is: shutter angle = shutter speed (seconds) × frame rate × 360°. A 180° shutter angle — the most common cinematic look — means the shutter is open for exactly half of each frame's duration.

The 180-degree rule is a starting point: at 24fps, a 180° angle means a shutter speed of 1/48s; at 25fps, it's 1/50s. Narrower angles (like 90°) create crisper, more stroboscopic motion (common in action sequences); wider angles (like 270°) add more motion blur for a dreamier look.

Example: at 24fps with a 180° shutter angle, shutter speed = 180 / (24 × 360) ≈ 0.0208s, or about 1/48s. Switching to a 90° angle at the same frame rate halves that to about 1/96s.

180° shutter angle (at 24 fps) ≈ 1/48 s — the cinema motion-blur standard.

High shutter angles (360°) blur more; narrow angles (45°) look stroboscopic — used intentionally in action scenes.

Shutter angle ties frame rate to exposure time on rotary-shutter cine cameras and many video modes.

News and documentary crews sometimes shoot 90° shutter at 24 fps for sharper motion during handheld follow shots — converts to ~1/96 s, stiffer than cinematic 180° / 1/48 s default at the same frame rate. Documentary crews use 90° at 24 fps (~1/96 s) for sharper handheld motion — stiffer than cinematic 180° / 1/48 s at the same fps.

LED flicker from cheap arena lights interacts badly with narrow shutter angles — if banding appears at 1/96 s, widen angle toward 180° or sync to AC line frequency where possible. LED banding at 1/96 s under cheap arena lights — widen toward 180° or sync to AC line frequency when stripes appear in video.

At 24 fps default, 180° → 0.0208 s (1/48 s). Doubling frame rate to 48 fps while keeping 180° halves shutter time to ~1/96 s — motion blur halves unless you widen angle to 360° for a dreamy look. 48 fps with 180° halves shutter time versus 24 fps at same angle — motion blur halves unless you widen angle toward 360° for dreamy motion.