How to remove LED and fluorescent flicker from video

LED and fluorescent lights are everywhere: offices, gyms, shops, ranges, stadiums, your kitchen. They're also the two kinds of light most likely to leave flicker and banding in your video, especially in slow motion. This guide covers how to recognize each kind of LED and fluorescent flicker, and the practical ways to remove it on an iPhone or on a computer.

What LED and fluorescent flicker looks like

Both kinds of light pulse with the mains power, 100 or 120 times a second depending on where you live (here's why). A camera recording at high frame rates catches those pulses, and they show up in a few recognizable ways.

Pulsing

The whole frame brightens and dims together. This is the simplest case and the easiest to correct, because a single brightness adjustment per frame can cancel it.

Banding

Light and dark stripes cross the frame, either standing still or rolling slowly through it. Banding comes from the sensor's rolling shutter: the lines of the image are captured at slightly different moments, so some catch the light at its peak and others in a dip. LEDs that switch hard on and off, including most dimmed LEDs, produce the sharpest bands. Fluorescent tubes tend to give softer, wider ones.

Regional flicker

Different parts of the frame flicker out of step. Large buildings often split their lighting across the three phases of the power supply, so neighboring fixtures peak at different moments. Mixing light sources, say LED panels plus daylight from a door, does something similar. Regional flicker is the hardest kind to fix, because no single correction suits the whole frame.

Color flicker

Fluorescent tubes, and some LEDs, shift in color as well as brightness during each cycle, because their red, green and blue output doesn't rise and fall in perfect step. You'll see a green or magenta tint coming and going with the flicker.

Removing LED flicker on iPhone

If the clip was shot on your phone, the quickest route is to fix it there. Deflicker is built for this. It reads the clip straight from Photos and gives you two engines.

• On iPhone. Runs entirely on the phone, with nothing uploaded. Its default Smart method measures brightness area by area across the frame, so it handles pulsing, bands and a fair amount of regional flicker without disturbing moving subjects. The Bands method targets rolling stripes directly, and Deep rebuilds each frame's tone balance, which helps with color flicker.
• Fusion. Our strongest fix, for deep LED flicker and regional flicker that the on-device engine can't fully even out. Fusion tracks every pixel across frames and rebuilds the light, running on our GPUs. It uploads only the clip you choose, which is deleted within 24 hours.

The clip at the top of our home page is a good example of hard LED flicker: an indoor range lit by LED fixtures that pulse out of step with each other, filmed on an iPhone. The right half shows the Fusion result.

For a full walkthrough with settings, see how to fix flickering slow-motion video on iPhone.

Removing LED flicker on a computer

Desktop editors have their own tools, and they make sense if your footage is already in an editing project:

• DaVinci Resolve Studio has a Deflicker effect in its ResolveFX Restore group, with a preset meant for fluorescent light. It's part of the paid Studio edition.
• Flicker Free from Digital Anarchy is a dedicated plug-in for After Effects, Premiere Pro, DaVinci Resolve and Final Cut Pro.
• ffmpeg, the free command-line tool, has a deflicker filter that evens out whole-frame brightness. It doesn't target bands or regional flicker.

We go through each option, with commands and settings, in how to deflicker video without After Effects.

Why banding is harder to remove than pulsing

Pulsing is a single number per frame: this frame is 8% too dark, so brighten it by 8%. A simple deflicker filter does exactly that, comparing each frame's average brightness with its neighbors'.

Banding and regional flicker break that model. One part of the frame is too dark while another is too bright, so a whole-frame correction fixes nothing, and can even make the bright parts worse. The fix has to work locally, area by area or pixel by pixel. Then the next problem appears: when a person walks through a dark band, a local method has to tell the difference between "this area got darker because of the light" and "this area got darker because a dark jacket moved into it". Get that wrong and the area around moving subjects starts to pump.

That's why the stronger tools, Fusion included, follow motion across frames instead of treating each area as fixed. It's also why it pays to start with the gentlest setting that works and compare carefully around anything that moves.

Tips for the cleanest result

• Use the original file. Messaging apps and screen recordings re-compress video, and compression smears fine bands into blocky patches that are much harder to correct. Fix the clip from your camera roll.
• Deflicker before you edit. Do it before color grading, adding titles or stabilising. Text and graphics on top of the footage confuse the brightness measurement, and some edits change the frame timing.
• Trim first. If you only need a few seconds of a long clip, trimming saves processing time.
• Check bright areas. If light fixtures are blown out to white in some frames, that detail can't be recovered. Expect them to look flat even after the flicker is gone.

When reshooting is easier

If the moment can be repeated, a few changes at the source often beat any fix afterwards: switch off the worst fixture, turn dimmed LEDs up to full brightness, use daylight, or choose a frame rate that matches your power supply. Our guide to preventing flicker when filming on iPhone covers the specifics for 50 Hz and 60 Hz countries.