Magic Lantern Forum

Using Magic Lantern => Raw Video => Topic started by: yourstruelee on December 30, 2015, 09:04:30 AM

Title: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: yourstruelee on December 30, 2015, 09:04:30 AM
I've been shooting with 5D RAW (.MLV) for a few months now, and have noticed the glitch below. Basically, sometimes when there is clipping in the highlights, weird green patterns appear. Unnatural, almost chroma-key green, in seemingly random arrangements.

Any insight would be much appreciated, I haven't been able to find a fix. Specs/workflow after the jump. Thanks in advance!

(http://static1.squarespace.com/static/55d5709ee4b0d31220468071/t/56838ac09cadb697dd8f22be/1451461313091/?format=2500w)
(http://static1.squarespace.com/static/55d5709ee4b0d31220468071/t/56838b55c21b868c6d3a7473/1451461461752/?format=1000w)

Full video, artifacts begin at ~:33, in the bokeh:
https://vimeo.com/149247396

I am shooting on a 5D mkiii, with SanDisk Extreme Pro 160 MB/s CF Card, and recording .MLV files.
Post workflow: .MLV to .DNG via MLVMystic (I've played around with the settings in MLVMystic, no matter which options I choose the DNGs exhibit the artifacting) Then .DNG to ProRes (plus neatvideo and 'add noise') in After Effects. Online in Premiere.

Any insight is appreciated. Thank you!
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: mothaibaphoto on December 30, 2015, 09:44:21 AM
ACR debayered with such artifacts?
Can't believe that.
Please, share one DNG file.
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: Kharak on December 30, 2015, 12:33:04 PM
You need to elaborate more on your workflow and where your Green Artifacts start appearing.
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: dmilligan on December 30, 2015, 04:49:10 PM
please upload a short MLV file the exhibits the problem
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: yourstruelee on December 31, 2015, 01:09:58 AM
Thanks for the quick responses!

Here is a download link with both the original .MLV file and some sample .DNG frames converted using MLVMystic.
http://we.tl/4b5vFYlNKf

After further experimentation, it looks as though MLVMystic may be the culprit. Converting the same MLV files to DNG using MlRawViewer didn't yield any artifacts.

.DNG Frame converted with MLVMystic:
(http://static1.squarespace.com/static/55d5709ee4b0d31220468071/t/56847184cbced6a0157728d7/1451520398930/?format=2500w)

.DNG Frame converted with MlRawViewer:
(http://static1.squarespace.com/static/55d5709ee4b0d31220468071/t/5684719fdc5cb4c79e8a4563/1451520420911/?format=2500w)

There is some banding in the highlights, but it sure as hell beats the alternative. Thanks all!
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: goldenchild9to5 on December 31, 2015, 02:36:52 AM
@yourstruelee WOW.. such a drastic difference between the two.  MLVmystic has a lot more noise and a shift in color it could be the exposure.. were they @ the same exposure?  Gonna do some testing myself.  From those findings I may have to switch my converter from MLVmystic to MLRawViewer no wonder I've been getting those weird color shifts in my footage.
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: DeafEyeJedi on December 31, 2015, 07:00:42 AM
and what's wrong with MLVFS, guys?

Or let alone MLP?

Those two rock my socks, BIG time!

p.s. Thanks for the file and I'll test it out on my end to see what shows up. Btw which glass were you using?
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: yourstruelee on January 02, 2016, 04:25:40 AM
Quote from: goldenchild9to5 on December 31, 2015, 02:36:52 AM
MLVmystic has a lot more noise and a shift in color it could be the exposure.. were they @ the same exposure?

The two stills are a little misleading - The MLVMystic DNG frame had been tweaked in ACR/AE, but the MlRawViewer frame was untouched. The differences in exposure/grain is probably due to me playing with those settings -- they are the same exact frame.

Quote from: DeafEyeJedi on December 31, 2015, 07:00:42 AM
Btw which glass were you using?

This was shot on the Canon 16-35mm F2.8. Thanks for the feedback!
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: goldenchild9to5 on January 02, 2016, 08:21:52 PM
@DeafEyeJedi I gotta try those.. @yourstruelee gotcha they had been tweaked thanks for letting me know.   
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: Mehmet Kozal on January 03, 2016, 07:36:59 PM
Quoteand what's wrong with MLVFS, guys?

MLVFS is the best as long as chroma smoothing is not needed. But if you use chroma smoothing, it will do the same but on clipped shadows. Opposite of what Mystic's doing.
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: anDyIII on June 22, 2016, 12:52:18 AM
Similar issue here found today in some footage shot with 5D mark III and 1.1.3 build from 16 May.

Highlight clipping is visible in MLRawViewer but also in CDNGs coming from the latest version of raw2cdng.

(https://s32.postimg.org/7p6jwtait/Clip_highligt.jpg)
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: pc_bel on June 22, 2016, 01:38:24 PM
@anDyIII
Yes, same for me (5DmkIII, 1.1.3). Magenta highlight clipping in MLRawViewer (allways) and now in cDNG's from raw2cdng 1.7.5. Not in raw2cdng 1.6.5
:(
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: allemyr on June 22, 2016, 07:40:16 PM
Try raw2cdng 1.6.1 is my advice! 1.6.5 does also work but I did discover a sync issue between audio and video when they are different length. 1.6.1 work flawelessly!
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: allemyr on June 22, 2016, 07:43:04 PM
To learn from the posts above, it's not the actual footage itself that cause the issue.
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: anDyIII on June 22, 2016, 10:30:04 PM
I'll try with older versions of raw2cdng, even if i like the latest changes and fixes.

Anyway, if someone wants to investigate further here is a frame with the clipping issue converted with raw2cdng 1.7.5.
http://www.mediafire.com/download/cbaavvv636hxkz2/M212033D00193.dng (http://www.mediafire.com/download/cbaavvv636hxkz2/M212033D00193.dng)
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: squig on June 24, 2016, 01:34:17 AM
@anDyIII I opened that dng in photoshop: there's no clipping.
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: anDyIII on June 25, 2016, 04:22:32 PM
Thanks squig, I also checked a bunch of frames quith Photoshop and they look ok, but I think this is because it reads them differently from Resolve and other tools.
Now we should understand if the issue comes from 1.1.3 builds or from the way all converting and grading tools read highlight information in those frames.
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: squig on June 26, 2016, 06:17:53 AM
It sounds like a problem with the debayering tools because the file has already gone through the MLV to dng conversion process, and ACR is debayering it properly. I debayer my 5D MK3 MLV files with MLVFS/Adobe camera raw/After Effects because the debayered IQ is noticeably better than Resolve. The only drawback is it's a slower and less convenient method.

Did you select the "highlight recovery" box in Resolve?
Title: Re: Green Clipping Artifacts in Highlights [5DMKIII]
Post by: allemyr on June 26, 2016, 07:26:24 PM
I'am a big fan of Davinci Resolve! So my comment is from that point of view :) Just use a proper MLV converter like raw2cdng 1.6.1 and the problem should be gone even if you are using resolve after that. When I render out graded footage from resolve I get over 50 fps and the clips look like this movie I just made

https://vimeo.com/172286896

How many fps do you get from after effects when you graded some footage? And please don't tell me that my video looks bad without take a quick look:) Everyone is ofcourse right to use the tool that fits them the most but i can't understand the resistance against davinci resolve on this forum. Never had a problem like that and been using my 5D3 with resolve for a few years now.