Shooting grids for chromatic abberation removal

Hi all,

a DOP is expecting to see a lot of chroma issues on an upcoming shot, and has asked if I have a magic fix. I have been through a few of the suggestions off the Facebook, and struggled to get them to do more good than damage.

As he hasn’t shot a single frame yet, I wondered if I could formulate a lens grid to shoot that would allow me to create a custom fix for the issue per lens?

Has anyone done this before? I’m aware that the brightness of the image will have an effect, but I wonder if I can turn that to my advantage and get an idea at what luminance the issues begin to arise?


Gareth Parry

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If the DP expects problems then she can expect a camera test day and 3 days testing, right?

Non such thing as a magi fix for motion picture cameras and CA.

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Yeah, if they know the lenses they r using are prone to more CA then I would suggest different lenses if you can


You could always shoot grids, then separate the shots into r, g, and b and extended bicubic warp them back together. Or not, because doing that ahead of time is f’ing idiotic and the DP should just shoot with lenses that don’t abberate as much. You can always add it in post much more easily than taking it out.

I can’t say how good it would be for extreme cases, but the Sylens Matchbox is my go-to for removal and re-introduction. I usually don’t even use a grid, just adjust the chroma settings until it’s gone, then invert it with a second node at the end of the comp.

Filtering will kill you, but perhaps sprinkling a little sharpen might help. Honestly, if the DP is choosing vintage lenses for look (seems to be all the rage for the promo crowd) then they should fully embrace the full vintage glass look—CA and all…

Another option I used once upon a time was running the images through acr in AfterEffects, which at the time seemed to get me a sharper result but at the expense of time.

“I’ll take Things That Nobody in 2020 Should Give a Shit About for $1,000, Alex.”


Hi all, thanks for the replies and wisdom.

I’m not so sure this issue is solely based around artistic lens choice though. I’ve seen a lot of quite pronounced issues on all of our HDR shows in high contrast areas, When those areas are brought down in the grade to stop them dominating the frame, the chroma artefacts become really obvious.

I spoke to the DP, and our new issue is how to get enough contrast ratio into a grid or checkboard to spark the issue. My idea was a half board, with black squares and gaps that you could hold up to the sky with the camera on full aperture

There is a chance that the issue isn’t chromatic abberation (which should be uniform across brightness), but halation, which looks similar, but is basically a ‘micro-glow’ around bright areas.

I am only aware of this phenomenon because of the definitive work on camera resolution: Steve Yedlin’s Resolution Demo