Moiré, refresh and shutter on LED walls

By James Jones, founder of Granary Digital · Updated 5 November 2026

Three faults, three causes

Film an LED wall and you may see a moving pattern on the screen, a flicker in the brightness, or a bar that rolls down the frame. They look alike on a monitor but come from different causes. Moiré is a spatial pattern from the screen grid. Flicker and rolling bars are timing faults between the wall's refresh and the camera's shutter.

Moiré

Moiré is an interference pattern that appears when two regular grids overlap at slightly different spacing or angle. The screen's pixel grid and the sensor's resolution are two such grids, and when the pixels sit close to what the sensor can resolve, the pattern appears.

Three things make it worse. A coarse pixel pitch brings the grid closer to the resolving limit. Focus that lands on the screen makes the grid sharp enough to show a pattern. A small change of camera angle moves the pattern in and out. A vendor's guide puts it plainly: halve the pitch and cameras can work about twice as close before the pattern appears.

Moiré does not come from the refresh rate. A higher refresh rate reduces the timing faults, but it will not remove a spatial pattern.

Flicker and rolling bars

Flicker and rolling bars come from timing. If the camera's exposure window does not line up with the refresh cycle of the wall, a band crosses the frame or the brightness pulses. Camera-grade processing typically runs at 3,840 Hz and above, and one trade article gives typical refresh rates of 3,840 or 7,680 Hz for LED walls.

Shutter angle plays a part here. At 25 frames per second a 180-degree shutter gives an exposure of 1/50 second, and at 50 frames per second it gives 1/100 second. A 180-degree shutter is the normal reference, so start there and test. Check the wall's spec sheet for the refresh rate, and ask the supplier whether the processing is rated for camera work.

A worked example

A 4-metre wide wall with a 1.9 mm pixel pitch has about 2,100 pixels across. A 4K sensor has 3,840 photosites across, so if the wall fills the frame width its grid covers roughly half of what the sensor resolves. The vendor describes that as approaching the band where moiré is worst. Focus, angle and distance decide whether the pattern shows, so test the shot at the actual distance and angle before the day.

Checks before the shoot

1. Get the wall's refresh rate and pixel pitch from the supplier, and ask whether it is camera-rated.
2. Set the shutter angle and frame rate, then film a test pan and tilt on the wall.
3. Check the picture on the monitor for bars, pulses and patterns, at the lens you will use.
4. Keep the focus on the talent or the set, not the screen, and move the camera a few degrees to check the pattern.
5. Keep the test footage and the settings with the shot so the same set is used on the day.

Granary hires in an LED wall for each job that needs one rather than owning one, so ask for the wall's specification when you plan the shoot. The green screen: how to get a clean key page covers the screen side of the same set-up. For planning pitch against viewing distance, the LED wall pixel pitch calculator is the next step, and the tracking markers and plate shooting checklist covers the camera side.

Sources

• Broadcast Bridge, Virtual Production For Broadcast: Video Wall Configuration, read 5 November 2026
• Dynamo LED Displays, LED screen moire on camera fixes, read 5 November 2026
• Wikipedia, Moiré pattern, read 5 November 2026
• Wikipedia, Shutter angle, read 5 November 2026

Related guides

• LED wall shoots: pixel pitch and viewing distance
• Tracking markers and plate shooting checklist
• All guides and tools