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So I found myself in a bit of a pickle, long story short, I have banding across some ceremony wedding images due to light flicker.

Here is an example of the issue I'm facing. What could be the best method to reduce the banding?

enter image description here

I have tried brushing over with soft brushes and playing with the opacity, making gradients and playing with the blending modes, can't seem to find anything that lessens the effect.

ADD: The inserted image is a screenshot of my Lightroom filmstrip, mainly as when they are at a smaller resolution the banding is more easily visible. I also don't feel 100% posting client images online. These were shot on A7III using silent shutter mode as I was told not to take photos during the ceremony, and having come from Canon DSLR's I've never been too aware of banding issues due to the science behind silent shutter. I was hoping I could somehow invert the base colour of the banding and have it nullify the effect.

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Some theory:

Silent shutter makes the camera to scan the image area line by line during a hundred milliseconds or so. Lights which flicker with the mains AC voltage pulses make bands because the light intensity varies several times bright and dark during one scan. You get some light from non-flickering sources, too. Thus the bands are as much exposure variations as white balance variations. You should have as little processed versions of the images as possible when you try masked exposure and color balance adjustments at the same time. It's possible that you find a single curves adjustment layer for both. That's because one adjustment layer can have different curves for R,G and B.

Do not expect the same fix to be valid for all images, because the placements of the bands can vary (=no sync; see NOTE1) and the proportion between fickering and of non-flickering lights varies between room areas and also from image to image because there's some movements

NOTE1: In the past high end video cameras had an option to be synced with flickering lights. That's because fluorescent lights flickered heavily and someone maybe also wanted to have a television in his video. Unfortunately I do not know if Sony has this option for Silent Shutter.

A fixing attempt

This is an attempt to insert a fix as a single Curves adjustment layer. The idea is to compensate both exposure and white balance variations with a single layer:

enter image description here

Proper curves for R, G and B were searched by having a black layer mask, there was only a stripe of white in the middle of one band, that one which seemed to be the strongest. Then more white was sprayed to the mask with a low opacity and low hardness brush. Spraying black was the way to take some superfluous white back

Unfortunately your image is a heavily processed thumbnail of the actual image, so nothing quarantees this makes enough correction to the full size image.

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Looks like there's both some chromatic aberration and some exposure difference in those bands, so I'd look at several stacked adjustment layers, each masked with stripes using a soft edged brush (constrain to horizontal lines by holding down shift whilst stroking the brush), working in RAW to keep vibrance and luminance available.

One adjustment layer for chromatic aberration with a pattern of correctly-spaced soft edge stripes as mask, another adjustment layer for value / brightness with a pattern of correctly-spaced soft edge stripes as mask, and in all probability a final overall adjustment layer for tone mapping with no mask.

You could consider switching to a LAB colouspace for processing, thus de-coupling value and colour, which might make adjusting the literal value without losing detail and colour easier... but not sure if it'll help - you'd still end up up having to address the slight hue shift between the bands separately.

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    Since it's the same hue shift in all bands (it looks like) wouldn't it be possible to just make one mask that covers all bands and treat them at once? – Luciano Jun 27 at 15:10
  • Yes. exactly! That was what I meant: One adjustment layer for chromatic aberration with a pattern of correctly-spaced soft edge stripes as mask, another adjustment layer for value / brightness with a pattern of correctly-spaced soft edge stripes as mask, and in all probability a final overall adjustment layer for tone mapping with no mask. I'll add that to my answer - thanks for the comment! – GerardFalla Jun 27 at 16:00

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