Tech Tools / Calculator
LED Refresh & Camera Flicker Check
Compare LED refresh, camera frame rate and exposure timing, and find candidate whole-cycle shutter settings.
Planning aid only. Timing heuristic only—not a certification. Advertised refresh alone cannot predict all rolling-shutter, PWM and scan artifacts. Verify equipment specifications and on-site conditions before the show.
Setup
Results
How to use this tool
An exposure containing an integer number of identical brightness-modulation cycles can average that modulation. The tool checks cycles per exposure, the nearest whole-cycle exposure, and the refresh/frame phase relationship.
Exposure time t = 1/shutter denominator, or t = shutter angle/(360 × fps). Cycles = refresh × t. Whole-cycle candidates are t = N/refresh, with integer N and t ≤ 1/fps. The nearest integer-cycle setting is only a candidate for testing.
Advertised refresh may not equal PWM or scan modulation. Rolling shutters, scan multiplexing, dimming, phase drift and non-genlocked clocks can still produce bands, even with exact-looking numbers.
FAQ
Can this certify a flicker-free setting?
No. It flags a timing mismatch, not a guaranteed result. Test the actual wall at show brightness, all relevant content and each camera shutter mode.
Why does frame rate matter?
Exposure must fit inside the frame period. Refresh/frame ratios also affect frame-to-frame phase and apparent beat behavior. A noninteger ratio is not proof of visible flicker.
What if I only know advertised refresh?
Use this as a screening estimate. Ask for the actual PWM/scan timing and test with a camera. Safe-looking arithmetic can still band.
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