GH4 V-LOG L noise reduction and color accuracy

I'd also like to apologize for my behavior. Like a lot of you I started out shooting 16mm and 35mm and then 3CCD cams and finally on to large sensor cams, and with each change we had to look at the camera as a tool, and not lose our minds when this tool that's suppose to make things better or easier, refuses to operate the way we're used to working, but to figure out the limitations and adjust accordingly. V-log will require that we adapt, if we want to use it. It doesn't expose or grade the way were used to, so there will be quite a number of growing pains.

I have a temper. I'll try to reign it in. Yes, I'm an asshole, but the goal here is to get and keep everybody up to speed.
 
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Personally I dont think we should be attacking each other, and trying to find workarounds and fixes for something that appears to be Panasonics fault.
They created it, they apparently tested it, and so did many beta testers, they did not provide documentation, they did not provide a specific GH4 LUT,
they did not map the gamma curve to the GH4's 12 stop DR, instead using the 14 Stop VC Log with much lower IRE rolloff for the GH4, it could not be more obvious.
Now I am not commenting wether Shians LUTS are good or not, all I am saying is the problem is there and a full re set does not seem to make it go away.
I would like to buy the NJ Assassin...and I may, but I sure as hell am not going to splash out $1,000 plus on an external recorder to try and find a workaround
for something that Panny should be fixing first.
As Barry Green said, anyone complained of this in all the the other 8 bit footage CLOG and SLOG2 etc...thats been floating around in older codecs for some years..nope!!
I have never heard of it, its the way they have implemented it in the GH4!! Plain and simple, they need to fix it..or refund the money that customers have spent on it.
If a new camera company did this they would be out of business before you could blink and eye.
Unless someone comes up with a miracle cure.. first reload the firmware, now press this button twice and hold down the Menu button at the same time and do a headstand and voila no more Magenta smearing.
Unless that happens...all anger should be directed at Panasonic!
 
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Shian Storm said:
I'd also like to apologize for my behavior. Like a lot of you I started out shooting 16mm and 35mm and then 3CCD cams and finally on to large sensor cams, and with each change we had to not look at the camera as a tool, and not lose our minds when this tool that's suppose to make things better or easier, refuses to operate the way we're used to working, but to figure out the limitations and adjust accordingly. V-log will require that we adapt, if we want to use it. It doesn't expose or grade the way were used to, so there will be quite a number of growing pains.

I have a temper. I'll try to reign it in. Yes, I'm an asshole, but the goal here is to get and keep everybody up to speed.
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For sure.

I also think that lots of people around the webs are trying log out for the first time. Vlog is rather tricky. One must expose very judiciously. especially in 8bit. But even in 10 bit you really have to nail down your exposure. The 10bit stuff I've tested is still very temperamental. Very scene dependent too. I just have a feeling that for the Gh4 what we have now is it. There will be no further enhancement as it seems to be pushing the cameras capability to the max.

But it does give a good insight as to where panny might go with the Gh5. But I will say that this whole Gh4 Vlog has been quite the debacle. So a message to Panasonic. Up your game.
 
Shian Storm said:
I'd also like to apologize for my behavior. Like a lot of you I started out shooting 16mm and 35mm and then 3CCD cams and finally on to large sensor cams, and with each change we had to look at the camera as a tool, and not lose our minds when this tool that's suppose to make things better or easier, refuses to operate the way we're used to working, but to figure out the limitations and adjust accordingly. V-log will require that we adapt, if we want to use it. It doesn't expose or grade the way were used to, so there will be quite a number of growing pains.

I have a temper. I'll try to reign it in. Yes, I'm an asshole, but the goal here is to get and keep everybody up to speed.
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This is the most unfaithful apology ever. You're just as talented as anyone else on here. Get off your high horse, with your worthless IMDB credits.
 
A lot of talk about the ninja assassin, but the blackmagic video assist is capable of downconverting 4k into 10 bit 422 prores for only $495..

Since many still publish in 1080, this is your best/cheapest solution to get most out of V log
 
I've just uploaded a new ZIP file which contains the following:

P1010069.MP4 - Internal VLog Profile 4096x2160x24.00p, ISO 400, f5.6 1/160th shutter, Sharpness -3 NR -5, ETTR exposure

P1010070.MP4 - Internal Portrait Profile 4096x2160x24.00p, ISO 400, f5.6 1/160th shutter, Contrast -5 Sharpness -3 NR -5 Saturation -2 Hue 0, exposure kept identical to Vlog (sky is overexposed)

P1010071.RW2 - Internal RAW still 4608x3072, ISO 400, f5.6 1/500th shutter, ETTR exposure (you can crop the center portion out for 4096x2160 to match video files for comparison)

Grab it here (110MB): http://downloads.visceralpsyche.com/...Test-Files.zip

I put the 18% grey card in the left corner of each frame so you can easily white balance each file, plus I white balanced to the same card for the video files before rolling, to maximise each channel's dynamic range.

In short, this package should give you all the files you need to make A-B-C comparisons and see what the camera should be capable of, and what it is giving us in each mode.

The only thing not here is a 10 bit file, as I don't have an external recorder to test with sorry. But for 8 bit comparisons, this should be complete.

Look forward to seeing your analyses.... my conclusion is that VLog is presenting unacceptable YUV chroma smearing, whereas Portrait looks fine. Both images pale in comparison to the dynamic range of the RAW still, so I feel there's a lot more dynamic range Panasonic engineers could draw out on the video side even if it's 8 or 10 bit.

Cheers,

Paul :)
 
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Been doing a lot of testing today. A few quick notes:

COLOR ACCURACY
1. V-LOG L with the VLOG-709 LUT is basically dead on color. Perfect grey scale. Makes skins tones look so much better than any other profile.
2. V-LOG L with Art Adam's LUT is off noticeably, color-wise. (Understandable, not for this camera.)
3. Natural with settings to match V-LOG as much as possible is not as color accurate as #1. Noticeably off. (I'll post examples soon.)

SAMPLING ERROR
1. Noticeable on neutral-ish image areas, in both shadow and middtones.
2. Present in all profiles, but really isn't noticeable until you have to push V-LOG L. You can push Natural harder without it becoming egregious.

NOISE
1. There's isn't any more noise than any other profile...the shadows are just opened-up to reveal the noise. Correct in post to match a natural exposure and deal with noise like you would with any other GH4 file.

DYNAMIC RANGE
1. I'm having a hard time clearly noting extra dynamic range from V-LOG L compared to Portrait with settings to match. If there's an improvement here, it's very small.
 
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joe12south said:
Natural (-5,0,0,-2,1 SHADOW +2, HIGHLIGHT -2)
View attachment 105362
http://blog.josephmoore.name/wp-content/uploads/2015/09/emma_portrait_1080.png

V-LOG L > VLOG709 LUT
View attachment 105363
http://blog.josephmoore.name/wp-content/uploads/2015/09/emma_vlog709_1080.png

V-LOG L > Art Adams 709 LUT
View attachment 105364
http://blog.josephmoore.name/wp-content/uploads/2015/09/emma_aa709_1080.png

(Uncompressed links below each thumbnail)

Notice the sampling error on the beige wall.
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Yeah the magenta issue is behind the vase, but it is just not that prominent in Natural and honestly I will say Natural is the best profile for this camera.
 
CustomerGH4 said:
Yeah the magenta issue is behind the vase, but it is just not that prominent in Natural and honestly I will say Natural is the best profile for this camera.
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In many regards, but the color accuracy of V-LOG L is not to be denied. Except for the nasty encoding error, the color is dead on. I think the ultimate for the GH4 would be for someone really skilled in LUT creation to create a low contrast Natural LUT that corrected it's color errors. That may be as good as this camera can get unless Panasonic radically improved the video pipeline, which is not bloody likely.
 
joe12south said:
In many regards, but the color accuracy of V-LOG L is not to be denied. Except for the nasty encoding error, the color is dead on. I think the ultimate for the GH4 would be for someone really skilled in LUT creation to create a low contrast Natural LUT that corrected it's color errors. That may be as good as this camera can get unless Panasonic radically improved the video pipeline, which is not bloody likely.
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That is what I meant, there is no point in the correct colors if they are ruined with the magenta issue. Better to try and grade the colors in other profiles than to hassle with the vlog issue.
 
I leave you kids alone for 5 minutes and you're already fighting over your toys and picking on the new kid. If there's gonna be another pissing contest put me down for a hundred on Shian. I use his LUTs and they're dope, much more sensical way of grading. Just imagine Shian's an Australian living in a USian body and you should get along fine.
 
squig said:
I leave you kids alone for 5 minutes and you're already fighting over your toys and picking on the new kid. If there's gonna be another pissing contest put me down for a hundred on Shian. I use his LUTs and they're dope, much more sensical way of grading. Just imagine Shian's an Australian living in a USian body and you should get along fine.
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haha, s'all good. Although maybe as a CG user you can try applying the new LUTs to V-log footage and post results, cuz I'm pretty sure everyone thinks I'm fudging the results to try to sell them on the value of CG.
 
Shian Storm said:
haha, s'all good. Although maybe as a CG user you can try applying the new LUTs to V-log footage and post results, cuz I'm pretty sure everyone thinks I'm fudging the results to try to sell them on the value of CG.
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Not having a GH4 could make that problematic.
Caring what this mob thinks: also problematic.
They do sometimes care what I think. Shian doesn't bullshit, and he produces some of the best looking graded toy camera stuff I've seen.
Carry on.
 
Shian Storm said:
haha, s'all good. Although maybe as a CG user you can try applying the new LUTs to V-log footage and post results, cuz I'm pretty sure everyone thinks I'm fudging the results to try to sell them on the value of CG.
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Did you do a new test and film outside with lot of stuff going on?
 
squig said:
I leave you kids alone for 5 minutes and you're already fighting over your toys and picking on the new kid. If there's gonna be another pissing contest put me down for a hundred on Shian. I use his LUTs and they're dope, much more sensical way of grading. Just imagine Shian's an Australian living in a USian body and you should get along fine.
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I'll do a hundred too.....:happy:

Thanks for the breath of fresh air. Got a bit heated in there.
 
visceralpsyche said:
Good stuff Joe.

You've motivated me to try to dial in exact colour for my own favourite profile, Portrait, and create a LUT to apply. I'm having good luck with dynamic range so far and the chroma smearing is essentially negligible (all internal 8 bit recording as I don't have an external recorder):
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I'm curious, why is PORTRAIT your favorite profile?

I've bit the bullet and am going to learn 3DLUTCreator. The kind of discrete manipulations required to dial in this exact of color correction isn't possible with normal grading tools, not even Resolve. I wish somebody more skilled would step-up because I'll have to learn as I go, but I'm fairly hopeful I can create a LUT that gets the Natural profile to match the color rendition of V-LOG > 709. From that point, I should be able to do the math and create reverse LUT's that turn the Natural footage into other LOG profiles, which would open it up to a lot of popular grading options.
 
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