GH4 V-LOG L noise reduction and color accuracy

joe12south said:
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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Portrait both lifts the skin tone mids and seems to give them a smoother/broader tonal range. Given that I shoot mostly narrative stuff with people in frame, it gives me the most bits where I need them.

You can see this easily by switching colour profiles from natural to portrait, while framing a person in the shot. The histogram moves right the most of all the profiles, but it seems to retain good highlight detail at the same time. I prefer it over the Cinelike profiles because the skin looks much nicer.

I'm going to do a bunch of profile tests tomorrow with a face in shot, to have a basis for building some nice LUTs to maximise dynamic range using Portrait, Natural and Cinelike-D and V.

Internally I'm not going to use VLog for anything as I feel I can get to the same dynamic range with my own mix of profile and LUTs, along with much easier shooting with zebras that work and a histogram I can trust.

Once I have some LUTs I'm happy with I'll post them up for all to test for themselves. No timeline for this - they'll be ready when they're done :D

Cheers,

Paul :)
 
visceralpsyche said:
Portrait both lifts the skin tone mids and seems to give them a smoother/broader tonal range. Given that I shoot mostly narrative stuff with people in frame, it gives me the most bits where I need them.
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Makes sense. I don't like how Portrait tries to "smooth" skin tones, but then again I don't particularly like the skin tone rendition of Natural, either.

When I charted all of the profiles (besides V-LOG L) Natural had the lowest across the board delta from known values. It was measurably the most "accurate" across the whole spectrum.

Yesterday I was able to perform the same test with V-LOG L. With no post work beyond the VLOG > REC709 LUT, the delta was significantly lower than Natural. Noticeably better. Immediately obvious when charts put side by side. With skin tones, the advantage is obvious even with nothing to compare.

Studying the two, I'm kind of hopeful that if I can correct enough discrete color errors, I can nudge Natural's color in line, and make skin tones look "right."
 
joe12south said:
Makes sense. I don't like how Portrait tries to "smooth" skin tones, but then again I don't particularly like the skin tone rendition of Natural, either.

When I charted all of the profiles (besides V-LOG L) Natural had the lowest across the board delta from known values. It was measurably the most "accurate" across the whole spectrum.

Yesterday I was able to perform the same test with V-LOG L. With no post work beyond the VLOG > REC709 LUT, the delta was significantly lower than Natural. Noticeably better. Immediately obvious when charts put side by side. With skin tones, the advantage is obvious even with nothing to compare.

Studying the two, I'm kind of hopeful that if I can correct enough discrete color errors, I can nudge Natural's color in line, and make skin tones look "right."
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If Panasonic were to release a Rec709 linear colour profile of the colour V-Log gives that would be a big step forward, especially for internal recording.

I'm going to play with profiles tomorrow to re-test the limits of each, and see if I can create some LUTs for each that bring the colour into line with V-Log to 709.
 
joe12south said:
...With no post work beyond the VLOG > REC709 LUT, the delta was significantly lower than Natural. Noticeably better...
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That's what is killing me... I'm just an amateur, do video for fun. Don't have the skills nor the equipment to measure.
But one thing I can say: I also use Natural but as soon as I compare both (Natural vs. V-Log, side by side) it was immediately obvious that V-Log (with LUT from Panasonic) is extraordinary as far as color is concerned.
The overall noise and banding/block issues may keep me away from V-Log - the method I found to work the best is using Neat Video attacking only chroma noise. But using this in every shot is a pain...

It's very hard to let V-Log go but I also post (in another forum), there's a need to have a LUT that could mimic V-Log colors in Natural footage (or CineD, Portrait for that matter), given a particular recording setting.
That's until Panasonic solves this problem (if ever).

BTW, today I was watching TV broadcast (news) and saw magenta/green casts/blotches everywhere. Really! Lots of problems with the same nature with professional equipment/crews. (irony) Thanks you guys ...!!!!!! :Drogar-BigGrin(DBG)
 
jopereira said:
BTW, today I was watching TV broadcast (news) and saw magenta/green casts/blotches everywhere. Really! Lots of problems with the same nature with professional equipment/crews. (irony) Thanks you guys ...!!!!!! :Drogar-BigGrin(DBG)
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I see it in other cameras too and also in non camera places. In real life too. Im in the matrix now.
 
CustomerGH4 said:
I see it in other cameras too and also in non camera places. In real life too. Im in the matrix now.
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LOL. You know if I stare at a textured popcorn ceiling with nothing else filling my vision, this weird visual noise happens that looks like my brain's visual compression algorithm breaking down, like it can't process all the detail and things get weirdly grainy.
 
Batutta said:
LOL. You know if I stare at a textured popcorn ceiling with nothing else filling my vision, this weird visual noise happens that looks like my brain's visual compression algorithm breaking down, like it can't process all the detail and things get weirdly grainy.
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I've always noticed that. Our brains are good at filtering it out, along with blending multiple exposures (we have HDR in our heads always working overtime!), but if you pay attention, especially in high contrast situations, you can see "noise" in areas that are being "lifted" by your brain.
 
After the debacle that is internal V-Log recording, I decided to go back to first principles, knowing I should be able to do a better job!

So I've been playing with the different linear profiles, settings etc in camera to figure out how to squeeze the ultimate dynamic range from the camera while keeping completely accurate colour, avoiding banding etc.

I'm not completely ready to reveal the secret sauce yet, but results so far are exceeding my expectations for what is possible internally.

The attached images are NOT V-Log, and they are recorded internally to a normal SD card.

ETTR was used to hold maximum highlights in each shot with NO over-exposure of any element.

Zurich.Footage.00_15_10_04.Still001s.jpg


Colour.Profiling.00_04_19_14.Still004s.jpg


Here are direct links to the uncompressed 4K PNG files (around 12MB each):

http://www.visceralpsyche.com/misc/web_images/Zurich.Footage.00_15_10_04.Still001.png

http://www.visceralpsyche.com/misc/web_images/Colour Profiling.00_04_19_14.Still004.png

Pay particular attention to the dynamic range. These are done at ISO 400. No noise reduction of any kind has been applied. Only my custom LUT I've been building has been applied to the out-of-camera image, along with some levels and saturation adjustments.

Those of you disappointed by V-log like me are going to have another (much, much cheaper) option soon that will make you see the GH4 and its 8 bit 4:2:0 recording in a whole new light!

Let's just say that V-Log internally is dead. I'm that confident.... ;)

Stay tuned.... :D
 
visceralpsyche said:
After the debacle that is internal V-Log recording, I decided to go back to first principles, knowing I should be able to do a better job!
Let's just say that V-Log internally is dead. I'm that confident.... ;)
Stay tuned.... :D
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Ha ha ha Debacle...AGREED!!!
Internally Dead, buried and hopefully cremated, I doubt wether we will see any ressurection here LOL!!
Panny had a year or near enough to get this right, basically they totally screwed almost every single aspect of it up...its amazing!!.
And every VLog topic is essentially either a discussion about using some band aid measure from keen users to try and get the thing working how it should have been in the first place, or a discussion about wether 10 bit will fix it...or a gripe fest.
It doesn't give you a lot of confidence in Panasonics engineers abilities, seems like they were totally out to lunch on this one.
But anyway...I really like your images, yes the range of everything you have got in the images seems really good, the whole thing of the GH4 is it can record 4K in 8 bit and look good.
and this looks really good to me eyes.
I would rather have something where the colors are slightly off, but you are not having to deal with magenta splotches all over the mid tones, or critical over exposure to get no noise in the shadows, protect the highlights etc...
I know we have to do the latter anyway, but with V-Log its a royal pain the arse!!!
I got the free version, and its made me decide I wont be buying it, I will erase it and return to the Natural and Portrait Profiles even tho I did really like certain aspects of V-Log, the negatives vastly outweighed the positives.
So anyway nice job on the images, keen to hear your views.
Cheers
 
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visceralpsyche said:
After the debacle that is internal V-Log recording, I decided to go back to first principles, knowing I should be able to do a better job!

So I've been playing with the different linear profiles, settings etc in camera to figure out how to squeeze the ultimate dynamic range from the camera while keeping completely accurate colour, avoiding banding etc.

I'm not completely ready to reveal the secret sauce yet, but results so far are exceeding my expectations for what is possible internally.

The attached images are NOT V-Log, and they are recorded internally to a normal SD card.

ETTR was used to hold maximum highlights in each shot with NO over-exposure of any element.

Let's just say that V-Log internally is dead. I'm that confident.... ;)

Stay tuned.... :D
Click to expand...

I've been doing the same thing and been having very good results with a tweaked Supertone setting. Portrait 0, -2, -5, -5, -1 along with a very important Highlight -5 that adds a nice roll-off. Skin tones are great and i could easily get the same DR as V-LOG in the grading process.
 
VLOG seemed to have worked out really nicely tonight when I brought it along with me to the LA Fair. Just wanted to see how it would handle lots of low and mixed light. Shot between 800-1600 ISO with the 12-35 Lumix. Put a speed boosted 18-35 on this camera and you have one nice looking low light image.

I'm not seeing much magenta issues with some of the LUTS I'm using and getting to know VLOG the past few days. I think VLOG is quite good. And if you need to shoot some serious stuff, record externally. For which I still think VLOG was designed for. But I'm confident now with the 8bit internal stuff and I've seen some other real nice stuff on the web.

For exposure, I'm just using the histogram ETTR without the right side getting too packed.

https://www.youtube.com/watch?v=2-ahGaB_keA
 
Yep, it's a LUT collection done by me with a REC709 to LOG LUT (with many color science improvements) and many stylized luts based on that.

Best thing is: Almost no artifacts unlike v-log. ;-)
 
OK folks. Here's what I've got so far for my LUT work:

Colour Profiling.00_08_12_04.Still009.jpg


Colour Profiling.00_08_21_07.Still010.jpg


Yep, you read that right. ISO 6400 on the second shot
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Almost no chroma issues at ISO 6400, only sensor luma noise. Zero at ISO 400. Perfect colour and tonality. Dynamic range from holding the sky and the sun's reflection off the white building in the background, to being able to see into the shadows under the green car and more.

Grab the full 4K PNG files here:

http://www.visceralpsyche.com/misc/web_images/Colour_Profiling.00_08_12_04.Still009.png

http://www.visceralpsyche.com/misc/web_images/Colour_Profiling.00_08_21_07.Still010.png

All from Cinelike D....

Thoughts? Questions? Just need to conduct some night testing to make sure the LUT holds up before releasing it for sale (it'll be cheap!), but given the science behind it I can't see that it'll be a problem
biggrin.png


Cheers from Berlin,

Paul
smiley.gif
 
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