Shutter Speed & Frame Rate Calculator
Recommended Shutter Speed:
Understanding the 180-Degree Rule
In cinematography, the 180-degree rule is a standard guideline that explains the relationship between frame rate and shutter speed. This rule dictates that the shutter speed should be double the frame rate (or specifically, the shutter angle should be 180 degrees) to produce motion blur that looks natural to the human eye.
If your shutter speed is too slow (e.g., 1/24 at 24fps), motion will look blurry and smeared. If it is too fast (e.g., 1/500 at 24fps), motion will look "choppy" or "staccato," often seen in action sequences like the opening of Saving Private Ryan.
How to Use This Calculator
To calculate your ideal settings, follow these steps:
- Frame Rate: Enter the number of frames your camera records per second (FPS). Common cinematic standards are 24 or 23.976. For slow motion, you might use 60 or 120.
- Shutter Angle: The industry standard is 180°. A smaller angle (like 45° or 90°) creates less blur and sharper motion. A larger angle (like 270° or 360°) creates more blur.
- Calculate: The tool will provide the denominator for your shutter speed (e.g., 1/50).
Common Frame Rate & Shutter Speed Combinations
| Frame Rate (FPS) | Shutter Angle | Ideal Shutter Speed |
|---|---|---|
| 24 fps | 180° | 1/48 (or 1/50) |
| 30 fps | 180° | 1/60 |
| 60 fps | 180° | 1/120 |
| 120 fps | 180° | 1/240 |
The Math Behind the Calculation
The formula to find the shutter speed based on frame rate and shutter angle is:
Shutter Speed = 1 / (Frame Rate × (360 / Shutter Angle))
When using the standard 180-degree rule, the calculation simplifies to: 1 / (FPS × 2).