Boneyard Tools

Shutter Angle Calculator

Convert between a shutter angle and a shutter speed for a given frame rate. Set the angle to find the matching 1/X second exposure, or enter a shutter speed to read its equivalent angle.

How to use the shutter angle calculator

  1. Enter your frame rate in fps.
  2. Set the shutter angle in degrees, or enter a shutter speed denominator.
  3. Read the matching shutter speed in seconds and its equivalent angle.

Examples

The 180 degree rule at 24 fps

24 fps, 180 degrees
1/48 second

Shutter speed to angle

24 fps, 1/48 second
180 degrees

Frequently asked questions

How does shutter angle relate to shutter speed?

Shutter speed in seconds equals the shutter angle divided by 360 times the frame rate. At 24 fps a 180 degree angle gives 180 over 8640, which is 1/48 of a second.

What is the 180 degree shutter rule?

Setting the shutter angle to 180 degrees gives an exposure of about half the frame duration, which produces motion blur most viewers find natural and cinematic.

Why use shutter angle instead of shutter speed?

Angle stays constant across frame rates, so a 180 degree look is consistent whether you shoot 24 or 60 fps. The matching shutter speed changes, but the motion blur feel does not.

What does a smaller angle do?

A smaller angle, such as 90 degrees, means a faster shutter and less motion blur, giving a sharper, more staccato look often used for action.

Does this assume an exact reciprocal shutter?

Yes. It computes the ideal 1/X second value. On a camera you would pick the nearest available shutter speed, which is usually very close.

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