Sometimes I get some footage with Rolling Bands caused by flickering lights. I would love to see a "Rolling Band" option in the Deflicker Effect to deal with this problem.

In some scenarios, the effect works excellently but in others, I just don't have more options to resolve the issue.

Cesar Tejada wrote:Sometimes I get some footage with Rolling Bands caused by flickering lights. I would love to see a "Rolling Band" option in the Deflicker Effect to deal with this problem.

I'm not sure it's fixable, because in different situations, the width of the flickering band is going to be different. How would the DeFlicker analyzer figure that out? It's not magic -- they have to actually go out and measure the brightness of adjacent pixels and then compare them to the frames before and after. To me, it's bloody amazing that it can work as well as it does.

There are deflicker tools offered by Re:Vision, Digital Anarchy DEFlicker, BorisFX Image Restoration, Granite Bay GBDeflicker, and several others. As far as I know, none of them can fix rolling bars, and I think some of that could be due to rolling shutter issues as well as frequency "beats" in the virtual shutter vs. the lighting itself. To my knowledge, there's still no way to fix rolling shutter problems, and that's something that everybody deals with.

What I have noticed is that OFX DeFlicker can at least reduce the problem, so there is that. BTW, the American Cinematographer Manual has a chapter on how to avoid lighting flicker in situations where you might have (for example) 60Hz lighting with a 50fps camera, or 50Hz lighting with a 24fps camera, or when you're shooting slow-motion. The best advice generally is: shoot tests first, and then look at it and see if there's any problem there. If there is, then change locations or go to a backup plan.

Marc, the Deflicker Effect can reduce rolling bands much better if you switch off motion analysis. The trade off then is that you will introduce motion smear in fast moving objects.
But I was able to salvage a multi-camera recording of a show where we got surprised by their new RGB-LED spots that started to flicker asynchronously during dimming in certain colors only.

Robert Niessner wrote:Marc, the Deflicker Effect can reduce rolling bands much better if you switch off motion analysis. The trade off then is that you will introduce motion smear in fast moving objects.

Yes, I've run into that as well: we solved the flicker, but the price we had to pay was motion smear. In some cases, I've been able to get around that by drawing a mask around the worst part of the frame and confining the DeFlicker just to that area, for example, the ceiling lights. It's not always perfect: if the camera pans, we're screwed, but it can help to a point.

Marc Wielage wrote:
There are deflicker tools offered by Re:Vision, Digital Anarchy DEFlicker, BorisFX Image Restoration, Granite Bay GBDeflicker, and several others. As far as I know, none of them can fix rolling bars, and I think some of that could be due to rolling shutter issues as well as frequency "beats" in the virtual shutter vs. the lighting itself. To my knowledge, there's still no way to fix rolling shutter problems, and that's something that everybody deals with.

I'd a search online and Digital Anarchy DEFlicker has a Rolling Bands Preset to remove this flicker issue. So that demonstrates is possible to have a tool that at least reduces the problem. Of course, I can just buy that plugin, but for me right now it's a little bit pricy, and flicker it's something that I rarely encounter in my editing sessions.

In this case, I was able to reduce the rolling bands manually in Fusion. I created some rectangular masks and animated them with a linear movement. I used that masks to drive a color corrector node, increase the brightness and at least reduce the issue.

Cesar Tejada wrote:I'd a search online and Digital Anarchy DEFlicker has a Rolling Bands Preset to remove this flicker issue. So that demonstrates is possible to have a tool that at least reduces the problem. Of course, I can just buy that plugin, but for me right now it's a little bit pricy, and flicker it's something that I rarely encounter in my editing sessions.

I just checked out the demo and it looks terrific. I'll put Digital Anarchy Flicker Free 2.0 on my purchase list.