Blackmagic Forum

I've attached 2 screen grabs from 2 clips I'm processing in Davinci Resolve 16. But I have many other examples with the same issue. A purple fringe, like chromatic aberration appears round the highlight parts of the image. All the white is blow out (255,255,255) and the purple seems to be where there is just a touch of faint texture. The clips are captured with a new Blackmagic Pocket Cinema 4K, BRAW (Q5). The clips did not show the fringing when first loaded to the timeline. But the first process I applied was to correct the colours using Color Match on the Color Page with the XRITE ColorChecker (Classic 24 patch) that I had placed in the clip. That is when the purple fringe appeared. I've tried this with about a dozen clips and the same result. Is this a problem with using the Color Match and is there a way to avoid/correct it?

Forget such automatic processes and learn manual grading.
If your original clips are fine, you'll get good results with some experience.

Thank you for your opinion Uli but it would be nice if this is an error in DaVinci, that it be fixed. Its good to have a standard to guide workflow and the eye is not a very calibrated instrument unfortunately, it is cleverly adaptive. I like to color correct to a recognized baseline.

Impossible to tell from here, but there could be other reasons for it, including an incorrect workflow. If you can, link to a sample frame (including one with the color matching chart in in it).

For example: Did you tell the ColorMatch function the correct Source Gamma?
What were the settings for the clip in the RAW tab?
Screenshots of those two areas would be helpful.

Apart from that, in my experience Color Match will only give you acceptable results if you first get the picture into the ballpark manually.

Humble apologies. I deleted all my adjustments today and started again and now cannot reproduce the problem (although I had reproduced it several times yesterday). I think you both are correct. By getting the highlights, shadows then mid tones in the right ball park then applying the Colorchecker the purple fringe does not appear. I think my RAW settings are good and I did set GAMMA to Blackmagic 4K Film. I checked White level. I haven't got used to Nodes yet, I think I'm making adjustments arbitrarily in different Nodes. I need to establish a good workflow, I need to re-watch the BM Training videos. I'm new to BMPCC4K and DaVinci and am just experimenting with high contrast situations. Thanks for your feedback.

Very nice!