A stage looks evenly illuminated, but the photograph contains dark horizontal bands. With an electronic shutter, sequential capture can interact with a light source whose brightness changes over time. Different image areas are then recorded under different illumination. Because we do not always notice that flicker, the fault can initially look like a file problem.
Test before the event
Photograph an even surface and then the subject under the lighting actually being used. Try several shutter speeds because bands may be strong at one setting and barely visible at another. Inspect saved images rather than only live view. Different shutter and readout methods can behave differently there.
An anti-flicker function may help, but it is not available with every shutter mode and cannot cover every lighting frequency. Some cameras include additional fine adjustments for high-frequency flicker. The model’s instructions explain which function applies. A universal recommendation for one shutter speed can fail with differently controlled LED fixtures.
Test a stage in three frames
Before an event, photograph an evenly lit wall or stage using the intended settings. Use the same source that will illuminate faces later. Enlarge the file because faint bands are easy to miss on the camera display. A photograph of the bright street outside says nothing about the behaviour of the stage LEDs.
Then make a second exposure with the mechanical shutter, if available, and a third at another suitable shutter speed. If stripes change or disappear, you have a useful indication of interaction between illumination and readout. Keep brightness and framing as comparable as possible. A much darker frame may merely conceal stripes instead of solving the problem.
Repeat the test if lighting is later dimmed or switched. Settings that work during setup may not continue working during the actual show. An anti-flicker function may help, depending on camera model and light source. Also inspect movement and expression: a stripe-free photograph taken too slowly may still be unusable for the action. The workable compromise must meet both requirements.
Change shutter type deliberately
If noise is acceptable, test the mechanical shutter. It may reduce the problem, but it is not immune to flicker under every condition. An electronic first curtain is also different from a fully electronic shutter. Do not confuse their menu labels.
A longer exposure may average several brightness fluctuations, but it increases the risk of subject movement. That can work for a quiet interior and fail for dance or sport. Seek a usable compromise between movement rendering and even illumination. Where possible, another part of the stage under a different light source may help.
Do not confuse different kinds of banding
Bands in heavily brightened shadows may have causes other than light flicker. Check whether they are visible in the normally exposed original and whether they change with shutter type. Colour gradients with too few tonal steps are another processing issue again. A clean comparison frame in daylight helps separate lighting, capture method and later processing. Keep test files with their capture data so the successful combination can be repeated.
