Shutter Angle Exposure Calculator
What exposure time and motion-blur fraction correspond to a shutter angle at your shooting frame rate?
Method, formula and assumptions
Exposure seconds = shutter angle/360 / shooting FPS. The reciprocal describes an equivalent shutter denominator. Modeled smear = image-plane pixels/second x exposure seconds.
Input definitions and supported units
- Shooting frames per second: Measured or assumed numerical value, from 0.1 to 10000; must be positive.
- Shutter angle (degrees): Measured or assumed numerical value, from 0.01 to 360; must be positive.
- Image-plane motion (pixels/s): Measured or assumed numerical value, from 0 to 1000000; zero is supported where the stated method permits it.
Worked example with answer
24 fps at 180 degrees exposes for 20.8333 ms, equivalent to 1/48 second, within a 41.6667 ms frame interval. Motion at 120 pixels/s smears 2.5 pixels.
How to use the results
The smear input uses measured motion on the recorded image, not subject speed in meters. Shutter angle controls exposure as a fraction of each frame interval.
Results retain full precision internally and display up to four decimal places. Very small nonzero results use scientific notation rather than appearing as zero. Check the labels before comparing values across units.
Limitations and references
Does not model rolling shutter, strobing, acceleration or subjective motion appearance. Available shutter settings and actual exposure timing vary by camera.
RED 101: shutter angle. Undated manufacturer tutorial checked October 11, 2026; no camera-specific preset is assumed.
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- Casey RowanUnits, conversions & measurement
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