How to Film a Screen Without Flicker

The quick fix

1. Set the screen to 60 Hz and its brightness to 100%.
2. Set your camera's shutter speed to 1/60 (or a 180° shutter at 30 fps). In countries with 50 Hz power, try 1/50 if the lights in the room flicker.
3. If a band still rolls slowly, fine-tune the shutter with your camera's clear scan or synchro scan setting until it stops.
4. Ripples or rainbow patterns? Move the camera a little, change the zoom, or focus slightly in front of the screen.
5. Control brightness with the camera's aperture or an ND filter, not by dimming the screen.

Rolling bands and flicker

A screen redraws itself many times a second, usually 60. Your camera captures each frame over a short time set by the shutter speed. When the two do not line up, each frame catches the screen part way through a refresh, and you see dark bands or a pulsing image. Matching the shutter to the refresh rate, 1/60 for 60 Hz, lines them up.

Phones and many mirrorless cameras read the sensor from top to bottom, so a mismatch shows as a band that rolls up or down. Most cinema and mirrorless cameras let you set the shutter in fine steps (Sony calls it clear scan, Panasonic synchro scan). Adjust slowly while watching the monitor until the band stops moving or disappears.

On a phone, the built-in camera app usually picks its own shutter. Use a pro mode or an app that lets you set it manually, and set it to 1/60 at 30 fps.

Flicker from screen dimming

Many displays dim by switching the backlight on and off very fast, called PWM. Your eye does not notice, but a camera does, as flicker or stripes. Most screens only do this below full brightness, so set the display to 100% and control exposure with the camera instead. If the screen is too bright for the scene, close the aperture, add an ND filter or lower your ISO.

Moiré: rainbow ripples

Moiré appears when the grid of pixels on the screen lines up with the grid of pixels on the camera sensor. The result is wavy, often rainbow-colored lines that move as the camera moves. Any of these breaks it up: move the camera closer or further away, change the zoom a little, turn the camera so you are not square to the screen, or focus slightly in front of the screen so the pixels soften. A shallow depth of field with focus on the actor usually solves it on its own.

Reflections and color

Screens are glossy. Look at the screen from the camera position and flag or move any light you see reflected in it, including windows. A polarizing filter can reduce reflections on some screens, but on many LCDs it darkens or tints the picture as you turn it, so check before you roll.

Most screens are a cool white of about 6500K. Under warm tungsten lights they look blue on camera. Either set the screen warmer, for example with the warmth slider on the white screen, or let it stay cool for a deliberate contrast.

High refresh and OLED screens

Gaming monitors and new phones may run at 120 Hz or more and change rate on their own. Lock them to 60 Hz in the display settings before you film. OLED screens refresh in a rolling pattern of their own and can show a dark band at fast shutter speeds; the same shutter matching fixes it.

Questions