Lighting
Strobe / PWM on Camera
01 — Definition
Two sources of flicker on camera. The strobe is a deliberate rapid flash, a stroboscopic effect that beats against the camera shutter and creates banding or partial flashes. PWM is the invisible on/off dimming of LEDs. Both clash with the camera's rolling shutter: as soon as the flash or PWM period does not divide evenly into the frame exposure, the camera catches part of the illumination as rolling bands.
02 — In the field
An LED wall or fixture banding on camera? Start by matching the camera shutter to a multiple of the mains or PWM frequency — 1/50 in a 50 Hz country, for instance. If that is not enough, raise the fixture PWM rate above 3 kHz or drop the strobe.