Inside the booth
Check flash synchronisation before building a booth sequence
A flash can illuminate only part of a frame when exposure timing is incompatible.
If a booth uses an external flash, confirm that the camera’s shutter and flash can work together before a session. A flash that fires at the wrong time may create a dark band or inconsistent frame illumination.
Start with the camera manual
Flash synchronisation limits depend on the camera, shutter mode and flash system. Manufacturer manuals document supported sync modes and shutter limits. Avoid copying a numeric setting from a different camera body; electronic shutter modes may have different behaviour from a mechanical focal-plane shutter.
Test across the strip
Take several frames of a neutral target at the actual camera position and inspect top, middle and bottom brightness. Repeat after any change to shutter mode or flash trigger. A single good frame does not prove that every exposure in an automated sequence is synchronised.
Record the working configuration
Write down camera body, lens, shutter type, flash, trigger and confirmed mode. If the band persists, make a test under continuous light to distinguish flash timing from an LED flicker issue. Do not open or modify a flash unit to diagnose an image artifact.
Sources & further reading
Sources for the specific facts and product descriptions above. Our worked examples, interpretations and practical suggestions are original editorial guidance.
- Canon, EOS R10 Product Manual: Shooting with SpeedlitesCamera manufacturer current product manual