Shutter Converter
Convert between shutter speed and shutter angle for any frame rate. Essential for cinematographers applying the 180° rule.
Input
Results
Related Tools
How the Shutter Converter Works
The 180° Rule
The shutter angle describes how long the shutter stays open relative to a full frame cycle (360°). At 180° the shutter is open for exactly half the frame time — the sweet spot for natural motion blur in cinema. This is where the 180° rule comes from: keep your shutter angle at 180°, and your motion blur will look filmic.
The FormulaAngle → Speed: shutter_time = angle / (360 × fps)
Speed → Angle: angle = 360 × shutter_time × fps = 360 × fps / denominator
Example: at 24 fps with a 1/48 shutter, angle = 360 × (1/48) × 24 = 180°. At 25 fps with 1/50: same result — 180°.
Common Shutter Angles90° — Crisp, staccato motion. Sports, action, documentary combat footage.
180° — Standard filmic look. The default for narrative cinema.
270° — Dreamy, heavily blurred. Stylised or psychedelic sequences.
360° — Shutter fully open the whole frame. Maximum blur, rarely used.
A shutter angle greater than 360° is physically impossible — the shutter can't be open longer than one full frame cycle. That's why the minimum denominator increases with FPS: at 120 fps you need at least 1/120 to stay within 360°.