Resolve: green/blue tint in high contrast areas

In Davinci Resolve Lite 9, I am getting aberration-like fringing around areas of high contrast. Here is an overview of my workflow:

1. I shoot RAW format on a Canon 5D III.
2. I convert the RAW file to Cinema DNGs using RAWMagic.
3. I import to Resolve Lite 9.
4. I get green/blue pixels along areas of high contrast. (see examples below)

The weird thing is that when I take the footage into other programs (Adobe Camera Raw, Lightroom) the problem is gone. SMH.

Here is an example.





Any help is greatly appreciated!

Looks like chromatic aberration to me. Probably pixel skipping on the sensor. Other apps may be doing CA removal in the debayer processing.

[Dwaine Maggart]

Are you using a Mac with an AMD/ATI GPU and not using Mountain Lion?

Here's my setup...

Macbook Pro
OS X 10.8.2
AMD Radeon HD 6770M

Could this be the problem?

Here's my setup...

Macbook Pro
OS X 10.8.2
AMD Radeon HD 6770M

Could this be the problem?

Nope. It's not the ATI bug. It's just that you're using a hack on your camera, and some very (not even beta) alpha software to convert the footage that is the result of the hack. Welcome to the cutting edge.

Here's my setup...
Nope. It's not the ATI bug. It's just that you're using a hack on your camera, and some very (not even beta) alpha software to convert the footage that is the result of the hack. Welcome to the cutting edge.

Thanks. I'm enjoying this whole cutting edge thing.

If it weren't for the fact that I can get brilliant results from the same RAW files with Adobe, I might just give up and wait. Everyone says Resolve is the best grading tool. I guess I picked a bad time to start working with Resolve. But I'm gonna keep at it until it works.

I was able to use the following workflow and avoid the aberration/fringing.

1. Import into Premiere using Ginger HDR plugin.
2. Export ProRes 4444 .mov file.
3. Import into Davinci Resolve

I'm seeing a lot more detail and dynamic range. It's definitely noisier, and the noise is colorful. But overall I think I can work with this until I find a reliable Cinema DNG workflow.



Huge improvement over my previous conversion.

That's great that it helped. But it also means you're not working RAW. I'm in familiar with the GingerHDR plugin, does it let you generate a log image?

[CaptainHook]

Resolves RAW convertor doesn't seem to do anything to fix chromatic aberration or any other common RAW 'issues' that ACR/Capture One/etc automatically fix.
The same problem shows up with BMCC Raw files (magenta/green fringing) and you have to remove the CA yourself in Resolve.

That's great that it helped. But it also means you're not working RAW. I'm in familiar with the GingerHDR plugin, does it let you generate a log image?

True. That said, the result I get with Ginger HDR is much better than what I've been able to get with RAW (so far). I would prefer RAW, but being new to Resolve, I'm struggling a bit with the conversion, import, and cleanup process. Ginger HDR is allowing me to start get started with basic grading. Hopefully I will solve my RAW issues soon and then Ginger HDR won't be necessary.

Resolves RAW convertor doesn't seem to do anything to fix chromatic aberration or any other common RAW 'issues' that ACR/Capture One/etc automatically fix.
The same problem shows up with BMCC Raw files (magenta/green fringing) and you have to remove the CA yourself in Resolve.

Thanks. It's been interesting to see all the different variations of the same file coming into Resolve from different converters. Do you have any advice for how I might fix the CA/fringing in Resolve?

[Peter Chamberlain]

We plan to have Resolve v10 release later in Q3 and that will give you a few more controls to consider.
Peter

[CaptainHook]

As Peter says, R10 will have node based PTZR and RGB splitters etc that will help to recreate solutions like some do in Nuke etc, but unless they add some automatic correction available with a few sliders or buttons, it will still be a manual process i imagine. I also hope we can do channel shuffling in R10, as i would quite often like to shuffle various RGB adjustments into the alpha for creating masks etc.

For now if i have to fix in Resolve, i do some keying that works pretty well when magenta is the main problem (seems to be with my lenses/bmcc) since it's generally not a colour that otherwise appears in the shot and i don't have to worry about other isolating qualifiers. But it's a quick band-aid since ideally to 'fix' lateral CA you would use scaling etc. But at least it can very effectively remove the purple colour fringes.

ACR (lightroom)/Capture One/etc are most likely using focal length/aperture/focus distance/etc info contained in CR2 raw files to do advanced CA correction. I can't see Resolve ever maintaining a database like this, but could be wrong.