Frame rate, exposure time and rolling shutter

The 180-degree starting point

Frame rate is the number of recorded frames per second; exposure time is the duration each frame collects light. A 180-degree shutter corresponds approximately to 1/(2 × fps): 1/48 second at 24 fps, 1/50 at 25 fps and 1/60 at 30 fps. These are calculated starting points, not a guarantee of cinematic quality. Shorter exposure produces crisper motion; longer exposure produces more blur. Images intended for analysis may need different motion rendering from a film sequence. Choose the delivery cadence and intended effect first, then test the settings your camera actually provides. A 24 fps delivery does not require every source to be captured at 24 fps, but define the reason and playback treatment first. Synchronized dialogue and silent slow-motion material need different handling.

Readout time is not exposure time

A rolling shutter records different parts of the frame at different times. Fast panning can lean vertical structures; vibration can produce a wavy image. Shortening exposure may sharpen each row without removing the time difference between rows. Investigate aircraft vibration, angular speed and recording-mode readout behavior separately, even when a gimbal is fitted. Begin with controlled motion and a sound airframe, then compare recording modes on the same subject. A global shutter addresses rolling-readout distortion but does not eliminate ordinary motion blur, exposure errors or every form of lighting flicker. Record both stationary and moving views when diagnosing distortion. Waviness while stationary suggests more than pan speed; a problem limited to a particular turn provides a different clue.

Test flicker and slow playback

LED signs and stadium lights use different modulation schemes, so mains frequency alone does not reliably predict flicker. Record the actual lighting at the planned frame rate and exposure, and inspect enlarged playback. Note dimmer settings where known. For slow motion, distinguish capture rate from timeline rate: playing 60 captured frames per second on a 30 fps timeline at one captured frame per timeline frame doubles duration. Normal-speed playback is a different decision. Optical-flow interpolation estimates missing motion and can fail around branches, water and occlusions; inspect those areas instead of assuming the result is faithful. Test long enough to reveal periodic brightness changes. Repeat when the lighting changes, and save the light source, frame rate and exposure duration with the successful setup.

Sources and editorial scope

Explanations and exercises are original editorial material. Verify product-specific conditions against the linked documentation version.

1. Sony — Essential movie-recording settings ↗
2. RED — Global & Rolling Shutters ↗
3. RED — Flicker-Free Video Tutorial ↗

Research date: 21 October 2026. Check the linked version, supported hardware and applicable conditions. Evidence includes directly reviewed text and official search-index records.