Author Topic: RAW Purple/Green defringe (which current best method? Switch?)  (Read 776 times)

adrjork

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Hi everyone,

I've found many webpages about the same issue, some older some newer, but I can't find a clear and updated method to fix the purple/green fringe in Raw highlights (and perhaps a little general color cast in MLV files from 5D3).
Up to now I tried 4 methods:
1. Iliah Borg's method for BMPCC footage is based on RawDigger histogram analysis of the DNG file for finding the closest value to the extreme highlights noise and setting that value as white level of the DNG via Exiftool. But I must say that this 1st method doesn't work with me;
2. RawTherapee has a Defringe tool that sounds promising, but again I must say that this 2st method doesn't work with me;
3. Nick Driftwood's Resolve node-based method is artful and it works, but (quoting an article by Dave Kendricken) «Some users, however, felt this workaround was too much of a compromise to be considered a viable alternative to an Adobe Camera RAW workflow. (Even though appending nodes in Resolve makes applying 'de-fringing' corrections to many clips very fast, it isn't really ideal).» The article continues with the good news that Resolve 10 auto-magically fixes the fringe, but it's actually not true for me. Said that, I roughly agree with the fact that this 3rd method is rather old (Davinci 9) and it seems not “ideal”, not pretty clean;
4. ACR method appears to be that "clean" solution: it's simply based on Remove Chromatic Aberration option (Lens Corrections tab) and it works BUT only in ACR: importing the fixed ACR-DNGs in Resolve, the fringe is still there! as if the ACR corrections are NOT visible in Resolve (even exporting the original DNGs to new ACR-DNGs).

(Right here a little secondary question: ACR-saved-DNGs' size is about half the size of the original Switch-DNGs, why?)

Now, considering that I need to use Switch (for MLV to DNG conversion) which is the cleanest method that fixes the purple/green fringe AND lets me grade in Resolve?
Perhaps setting the white level in Switch? (but Exiftool method didn't give any result...)
Should I use IR filters? (Like BMPCC users...)

Thanks in advance for your kind help.

P.S. Just another couple of secondary questions:
1. In Switch mlv_dump, if you DON'T select the option (07) disable vertical stripes in highlights, means that Switch DOES fix the vertical stripes, right?
2. Time ago I had installed an old Switch. Today I installed Exiftool. Then I downloaded the updated Switch for overwriting the old one. Only at this point I read that Switch uses Exiftool, so my question is: could this 2 installations (Switch and Exiftool) be in conflict? Should I uninstall Exiftool?

Again, thanks a lot.

reddeercity

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #1 on: April 12, 2018, 05:33:43 AM »
 MLVProducer Is what you are looking for it's the open source version of A.E. ACR and can ran on a MAC read here . Why are you not using MLVFS  ? has all the options plus it makes Cdng's on the fly ,
I use it with blackmagic resolve . Just mount the .mlv and then import in to resolve or a.e. , premiere etc. .... you don't have take up drive space by extracting cdng's to a separate folder

adrjork

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #2 on: April 12, 2018, 07:04:40 AM »
Hi reddeercity, thanks a lot for your fast reply!

I've just tried MLVProducer few seconds (I didn't know it) and I must say it's a bit tricky for me:
-I didn't find the Defringe option, but it seems that the app does an automatic de-fringe because the fringe is almost gone... almost, because I must say that (to me) ACR does better the job (fringe completely gone);
-Once converted in DNGs with MLVProducer, the footage in Davinci appears completely wrong in temperature and tint and luminance... why?

I must admit that I was pretty happy with Switch (BUT the fringe issue) and it would have been perfect if ACR corrections would remain visible in Davinci... Nobody knows a way to export ACR corrections in a way they are visible in Davinci?

I can't use MLVFS because I use an Hackintosh (it means less compatibility with some piece of software, for example RAWMagic) and when I tried to install MLVFS (time ago) it crashed.

Danne

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #3 on: April 12, 2018, 07:22:15 AM »
There's a setting for chromatic abberrations in Mlv App, heard a lot of good things about it. That is you are exporting to prores otherwise acr through ae should work best. Note that Switch can export ae project files(cdng to prores) with a template working through aerender.

adrjork

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #4 on: April 12, 2018, 07:38:47 AM »
Hi Danne, thanks a lot for your reply.
Actually I'm not interested into Prores (at least until we'll see new raw version in action) nor in After Effects.
My current work is strictly linked to Davinci AND dng-files.
But seems that Switch hasn't a defringe option, while ACR has it. So it would be perfect (for me) if it would exist a solution to do the following workflow:
-MLV to DNG with Switch;
-DNG to defringed-DNG with ACR;
-ACR-defringed-DNG in Resolve (with visible ACR corrections).

Nobody knows a way to do it?

Danne

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #5 on: April 12, 2018, 08:21:11 AM »
That will not work without an intermediate file such as tiff, prores etc.

50mm1200s

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #6 on: April 12, 2018, 08:27:23 AM »
If you're using ACR, you can load LCP profile, IIRC. This would be the most accurate solution, since it's based on calculations of your lens. Here is a tutorial for creating custom profiles. But: the magenta cast in midtones is also affecting my images (on 50D MLV) and I can't solve it. Andy600 gave me some hints, but I couldn't fix it. I don't know if I'm too dumb on color grading or something is wrong with the MLV itself.

edit: you can import CDNG on Resolve and used the lens correction feature, it seems.

reddeercity

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #7 on: April 12, 2018, 11:24:15 PM »
Hi reddeercity, thanks a lot for your fast reply!
I can't use MLVFS because I use an Hackintosh (it means less compatibility with some piece of software, for example RAWMagic) and when I tried to install MLVFS (time ago) it crashed.
No that's not right , I been running Hackintosh for over 6 years now and never had a software issue with any video app's FCPX , A.E. , etc. ..... in fact MLVFS is all I use on my desktop (i7 Gigabyte Z77x-ud5h board) Hackintosh even with my fake MBP (i7 Toshiba p850-0c4) that's all I run . I have both on Yosemite , I even loaded my Real 5.1MP backup (clone) Yosemite OS on the Toshiba with the multibeast Linux bootloader and it was plug & play . If you would have looked in to the mlvfs Log files I'm sure you would have found the problem . I seen corrupted .mlv file crash mlvfs , but just a restart of the app fixes it -- It's nice to just click on the file and have it open up  :)   

adrjork

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #8 on: April 13, 2018, 12:06:51 AM »
No that's not right , I been running Hackintosh for over 6 years now and never had a software issue with any video app's FCPX , A.E. , etc. ..... in fact MLVFS is all I use on my desktop (i7 Gigabyte Z77x-ud5h board) Hackintosh even with my fake MBP (i7 Toshiba p850-0c4) that's all I run . I have both on Yosemite , I even loaded my Real 5.1MP backup (clone) Yosemite OS on the Toshiba with the multibeast Linux bootloader and it was plug & play . If you would have looked in to the mlvfs Log files I'm sure you would have found the problem . I seen corrupted .mlv file crash mlvfs , but just a restart of the app fixes it -- It's nice to just click on the file and have it open up  :)   
Hi reddeercity, thanks really much for your reply.
Unfortunally, for some reason my Hackintosh has compatible issues with various software: for example FCPX can't work at all, Rawmagic crashes, Isadora crashes, and all virtualization software as well (VirtualBox, Parallels, etc.) The reason... I don't know: perhaps the specific hardware, or the OS installation... I really don't know.
Anyway it's not a great problem: I don't use FCPX, and all the software in my workflow work fine.

Anyway, tell me, in your experience MLVFS does some defringe or CA correction? It operates automatically?

reddeercity

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #9 on: April 13, 2018, 01:21:39 AM »
Ok , not sure about defringe , here the first page .
https://www.magiclantern.fm/forum/index.php?topic=13152.msg127218#msg127218
it has basically , Bad pixel fix, Vertical banding correction ,Chroma smoothing & Full quality dual ISO working (cr2hdr-20bit)
I never had any issue with defringing , I feel the issue is poor Lens Glass or the coating -- I use canon EF "L" pro lens and never had the problem
I own 1 Sigma 50mm prime , even with that cheaper lens I can't see it . I always unselect all the option before export (5D2) maybe your issue is a 5D3 one
or the nightly built you use , have to try just the plain Vanilla build ?
How do you normally process you Cdng's ? you work flow , resolve ? A.E. ? do you use a intermediate ? Prores ?

 

mothaibaphoto

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #10 on: April 13, 2018, 02:39:30 AM »
Sorry, what is this all about?
5 years ago gone bug in DR, or lens artifacts, or what?
Can you please share one DNG?

adrjork

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #11 on: April 16, 2018, 07:42:42 AM »
I think (I hope...) I solved it.
First of all, the fringe in my case is lateral chromatic aberration caused probably by various things: anti-aliasing filter in 5D3, lens (Tamron 24-70), filter (Hoya UV), etc. and it's visible in highlights/contrast edges.
ACR manual Defringe is fanstastic and does perfectly the job, so one workflow could be MLV-to-DNG (Switch), then DNG-to-TIFF (ACR with Defringe), then grading TIFFs in Davinci (but losing RAW tab).
At this point the great question is: what is better, losing RAW tab for working with perfect TIFFs, or trying to solve the fringe directly in Davinci and enjoy the flexibility of Raw tab?
As I wrote, Nick Driftwood method works but in my opinion is not clean actually.
So I tried to find another node-only-based solution that's the following:
1. Splitter/Combiner: Green with just little luma denoise (3 in my case), Red and Blue a bit more (5 and 6);
2. A node after the combiner has saturation 0 and a very little sharpness (0.48), then it ends to a Layer Mixer;
3. Restarting from the source, a node isolates the fringe color (Qualifier) and desaturates it (in comb with Hue);
4. After this, another node with Gain 0.01 and a good point of blur (0.6) that ends to the Layer Mixer (2nd input);
5. After the Layer Mixer one last node with denoise (in my case Luma 2 and Chroma 10).
Basically this method mainly adds Qualifier (and noise reduction) to the old Nick D. method.
The result seems to be very near to the ACR quality.
I hope this could help.

50mm1200s

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #12 on: April 16, 2018, 08:26:02 AM »
Why TIFF? You can just use mlv_dump and open a dng sequence in after effects. Then, export in ProRes 444 or Lagarith lossless...

adrjork

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #13 on: April 16, 2018, 08:44:36 AM »
Why TIFF? You can just use mlv_dump and open a dng sequence in after effects. Then, export in ProRes 444 or Lagarith lossless...
Yes, you are right :)
(But if I read correctly somewhere, in AE even prores is YUV based, that implies a conversion in Resolve, and in theory TIFF should be ideal for quality.)

50mm1200s

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #14 on: April 16, 2018, 01:39:40 PM »
Yes, you are right :)
(But if I read correctly somewhere, in AE even prores is YUV based, that implies a conversion in Resolve, and in theory TIFF should be ideal for quality.)

I think you can manage this on project settings (first pic) and output settings (second pic):






Also, have you tried the lens correction, as I've suggested above? I think it would work better than manually adjusting chromatic aberrations...


adrjork

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Re: RAW Purple/Green defringe (which current best method? Switch?)
« Reply #15 on: April 17, 2018, 12:20:21 AM »
Thank you so much 50mm1200s!!!