By Test for LED flicker by shooting a series of images at progressively faster shutter speeds, starting at 1/60th of a second and increasing to 1/500th or beyond. Dark bands appearing across your frame indicate artificial lighting that cycles faster than your camera can capture uniformly. This phenomenon, called banding or the rolling shutter effect, occurs because LED and fluorescent lights pulse at frequencies tied to electrical currents, typically 100 or 120 times per second depending on your region’s power grid.
Switch your camera to shutter priority mode and photograph a white wall or neutral surface under the suspect …
