Motion
Motion Blur Calculator
Match shutter angle to frame rate for natural motion blur, and see what breaking the 180° rule looks like.
Runs entirely in your browser. Nothing is uploaded.
How to use
- Set your frame rate.
- Set the shutter angle, or use a preset.
- Read the exposure time per frame and the matching shutter speed.
- Watch the blur trail grow or shrink, with the 180 degree standard marked for reference.
Examples
- At 24 fps and 180 degrees the sensor is exposed for about 20.8 ms a frame, the natural cinematic look most footage aims for.
- Dropping to 45 degrees crisps the motion into a stuttery, staccato feel, the texture of war and action sequences.
- Opening past 180 degrees lengthens the blur trail for a soft, dreamy or flowing motion.
Frequently asked questions
What is the 180 degree rule?
It means setting a shutter angle of 180 degrees, which exposes each frame for half the time between frames. The resulting motion blur matches what audiences read as natural, so it is the default starting point for most cinematic work.
How does frame rate change motion blur?
Shutter angle sets the fraction of each frame that is exposed, so 180 degrees is always half a frame. But a higher frame rate makes each frame shorter, so the actual exposure time and blur per frame shrink even at the same angle.
When should I break the rule?
Narrower angles suit gritty, high-tension action where you want sharp, jittery motion. Wider angles suit dreamy or surreal sequences. Both are creative choices, used deliberately against the natural 180 degree baseline.
