GH6 Blotchy Skin?

EndCredits

EndCredits

Well-known member
Hey Team,

I am interested in picking up a GH6 but I have notice a fair amount of blotch skin in the footage I have seen online. It appears as a blotch of darker "orangish" skin, usually on the forehead or under eyes. You really have to be looking for it but I have had a similar issue with some footage I shot on GH5 for a documentary that caused issues in post for us.

Example:
https://youtu.be/_LuKJoCzy1A?t=78
You can see it under the eyes or the bridge of the nose in the close ups. It moves around and you have to look for it.

Example 2:
https://youtu.be/aG3jwVcKTWE?t=48
Forehead & top left hairline area

Anyone had an issue with this?
 
I have GH6 as well as GH5S. Traded my GH5 for the GH6. I always shoot Vlog so comments are for that. The GH5 and GH5S have some sharpening in the standard setup and a little more contrast. The GH6 is flat in comparison, not sure if this the difference between Vlog-L and full Vlog. . The comparison is with Color Managed to rec709 in Resolve. Personally I like the colours of the GH6 as there is more room to move in editing. I do not see the problems you seem concerned about compared to the GH5S now. GH5 has gone so cannot compare now but the GH5S has a better image than the GH5 anyway for comparison.
 
A general comment.

IR pollution is a known thing. We dont want IR frequencies not visible with the naked eye to be translated to data in the digital file.

This may result in purple brown dark areas, known well on the sony ex1.

Various makers do or dont havel levels of IR filtration in front of the sensor.

Now let us assume that that IR filtration is not perfect, well then it may (if too strong) cut some 'real' dark reds from the scene.

Now skin (especially male, aging - sorry DP review guys - certainy has darker red blodges) an overly strong IR filter in the camera system will show them up strongly as they filter dark red to black.


It is therefore entirely possible that different makers of cameras will render skin in that dark red zone in different manners.. so you could be correct in identifiying the GH cameras do this in a manner different to other brands.
This is of course before we apply IR cut filters in front of the lens

This balance of IRcut and sensor performance is so complex that I feel that ND installed in factory tuned to a specific chip should deliver results in a different class to buying some 'IR cut' filter off of amazon (or tiffen)

Led light sources to tend to have a weak delivery in the deep red spectrum, and any subject not illuminated reads as black.

So have a aging caucasean, a cheap LED light and the wrong camera and blotches are us.

Compare this with Marlene Deitrich lit with tungstens in the 1930s that have strong illuminance in the deep red spectrum (lightening blotches and skin imperfactions) and you have starkly better skin tones.

Of course a camera setup with strong IR filtration will not render your dark black wooly coat as brown purple.
 
I must be missing something. I've watched the clips you've listed on four different monitors in the edit suite. One of which is a true 10-bit, not that really matters here, Rec 709 grading monitor. The other three are BENQ PC monitors. Also watched the YT clips on two TVs. One being a run-of-the-mill Phillips LED TV and the other being a 55" LG C1 OLED and could not see the issues you are talking about. To hunt a bit deeper, I downloaded the highest bit-rate 1080 23.976 files I could from YT. Repeating the viewing process across all monitors and TVs, but this time using the downloaded files. This gives me a better image overall, but I still don't see this "blotchy" skin issue. Even following your pointers of under the eyes, bridge of the nose in close-ups. So I guess my observations won't be too helpful. Chucking the files in Resolve didn't really reveal anything out of the ordinary.

Off-topic observation.The videos appear to be graded to 709 levels, but the added graphics are using 100 IRE whites, which are in stark contrast to the video white peaks at around 95 IRE. For YT okay, but for broadcast we always grade graphic whites to 95 IRE.

Chris Young
 
Thanks for the replies. Chris, I think you have nailed it. I can't see the issue on my monitors at work but can at home. I have 2 Asus monitors at home and the issue is only visible on one of them. Weirdly I can only recreate the issue with GH6 footage so far, can't seem to find a clip from another source that does the same thing. Though that is more likely because I am interested in the GH6 right now. Totally not sure what the go is.

I am going to chalk this up to a poor quality monitor.

Thanks for the help :)
Sorry for the non issue :)
 
You must log in or register to reply here.
Back
Top