Photography Calculators

Timelapse & video

Shutter Angle Calculator

Motion-picture shutters are angles, not 1/50. Time = angle / (360 × fps). 180° at 24 fps is 1/48 s — the usual ‘film look’ of motion blur. In daylight that time wants ND, not f/16. Take a test shot (or a test clip) before you lock the angle for a whole interview.

Inputs

Units
°

180 is the default look. 90 is crisper / staccato. 270–360 is more blur (and more light).

fps

Project rate, or the rate you are recording if they match.

Results

Shutter
0.020833s
Shutter reciprocal
48.0

48 means 1/48 s. Set the nearest speed the body offers.

Recommended gear

Calculation method

A full circle is 360°. The fraction of the frame time the shutter is open is angle/360. Frame time is 1/fps, so open time is angle divided by (360 times fps). 180/ (360×24) = 1/48 s. Reciprocal is 1/time so you can match a stills-style shutter speed on bodies that do not speak degrees.

Exact formula

t = shutterAngleDeg / (360 × fps). Reciprocal = 1/t. Limits: Rolling shutter, flicker from lights, and the ND needed to hold 180° in sun omitted.

Saving the 180° look in sun

ND first, then ISO, then aperture if you still have light. Stopping down to f/16 to ‘make 1/48 work’ is how you get diffraction and a busy background you did not want.

Stills shooters

1/focal is a shake rule. 180° is a motion-blur rule. They only coincide by accident (50 mm at 24 fps is near 1/48).

Frequently asked questions

My camera only has 1/50, not 1/48.

Set 1/50. The look is the same for all practical purposes. Some bodies offer 1/48 in a ‘shutter angle’ or ‘fine’ shutter menu — use it if you have it.

High frame rate?

180° at 120 fps is 1/240. You need a lot more light (or ISO/aperture). Do not keep 1/48 when you jump to 120 or you will smear every frame.

Flicker from LEDs?

Match shutter to the mains (1/50 or 1/60 and multiples) even if that is not exactly 180°. A clean clip beats a pure angle.

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