Artifacts in Highlights

Started by psuarez, March 26, 2014, 04:53:05 PM

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I've discovered some artifacts when processing highlights.  I've been using RAWMagic to convert RAW files to DNGs and then using Davinci Resolve to color correct and export Quicktime movies.  As most of you know Resolve sees the DNG sequence as a movie and I can color correct directly.  On the master settings for the clip I've been applying the BMD Film color space and gamma and adjusting the exposure to 1 and checking highlight recovery.  This as a general rule of thumb gives me a good starting point from where to color correct.  At close inspection, I'm getting some magenta artifacts on the highlights at the edge of white with no detail.  The interesting thing is that if I use ACR to correct my DNG sequence I get no artifacts.  Any ideas?. Here is two 500% blowup of a window that shows what I mean.

I hope this is a good way to share photos.


My thought is they are lateral chromatic aberrations (LCAs) which occur because different wavelengths of light aren't all focused the same by lenses. ACR has the ability to defringe LCAs whereas Resolve doesn't.


I think it's caused by clipping in the red and blue raw channels. ACR has some clever highlight reconstruction going on that rebuilds lost information in R & B, taking it (I think) from the green channel. If it wasn't for this issue I would always opt for debayering in Resolve. Highlight recovery in Resolve adds a shoulder to the curve but if the raw data is already clipped it can't help. I don't think it's LCA related.
Colorist working with Davinci Resolve, Baselight, Nuke, After Effects & Premier Pro. Occasional Sunday afternoon DOP. Developer of Cinelog-C Colorspace Management and LUTs -


Thanks for the quick response.  For now I will debayer difficult shots in ACR and continue using Resolve for the bulk of my rushes.  Thanks again.


I thought the latest Resolve had fixed this issue?


i have seen them to and i feel like it was in the latest version of resolve using bmd film +highlight recover and sometimes if you move the WB around they go away. I also remember NOT seeing them when using the bmd lut + vision log which makes a extremely flat video but i dont remember seeing those artifacts any more. never saw them with arc. BMD debayer is definitely not as good as ACR but BMD so much faster. I wish we could combind adobe debayer with BMD speed and wow what awesomeness that would be!!!