GH5 Paul Leemings New LUT for HLG Footage

joe12south said:
Vesku,
You're not really looking at "stops" at that point, because the stop unit defines a doubling of light, and your display doesn't have enough contrast/brightness to display range. Thus the "compression" that you refer to.
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Thanks for thinking this with me. I have a TV with 1:4000 contrast and OLED has even much more. 1:4000 is exactly the light doubling 12 times. We can SEE much more than 12 stops with OLED. If a 8bit rec709 video has recorded/compressed 12 stops of light and I can see it how can someone say it is not possible or that I am sharing misinformation. GH5 HLG is very welcome update. Finally we can capture and SEE very wide DR without paid vlog and even with a good SDR TV/display.
 
Vesku,
Well, because technically, it's not REC709 if you do that. Instead, what you've done is made your own personal one-off standard that there is no agreed, consistent way to master or view. It's unpredictable, because my display device could have quite different characteristics. Standards usually represent a safe middle ground, not the outer limits of possibility. HLG is the closest thing to what you are looking for - it looks okay with both SDR and HDR displays.
 
joe12south said:
Vesku,
Well, because technically, it's not REC709 if you do that. Instead, what you've done is made your own personal one-off standard that there is no agreed, consistent way to master or view. It's unpredictable, because my display device could have quite different characteristics. Standards usually represent a safe middle ground, not the outer limits of possibility. HLG is the closest thing to what you are looking for - it looks okay with both SDR and HDR displays.
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Yes I know that the rec709 recommends 100nits and very low contrast for display. I still dont think many new OLED owner adjusts settings for contrast 1:100 and dull colors like rec709 says. If they use OLED default settings they are seeing always more than 12 stops of light doubling with any material.
 
Shirozina said:
I very much doubt your TV has 12 stops of display range / 1:4000 CR - that's marketing BS. I really can't help anymore with this and I think a bit of research on some basic concepts would be very beneficial and this is a good place to start http://www.cambridgeincolour.com/tutorials/dynamic-range.htm
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That's actually a good point. Display manufacturers play fast and loose with contrast ratings. The rating most closely associated with what you want - dynamic range within a single scene (frame) would be ANSI contrast, and very, very few manufacturers release this number because it's rarely impressive. For example, my projector has a dynamic iris so that it can adjust total light output up and down over time to effectively simulate a much wider dynamic range than it can produce on a single frame.

Either way, I think you should have a clear understanding of WHY camera profiles are what they are:
- Big manufacturers like standards
- Standards are built for the lowest common denominator
- HGL is a nice bridge standard
- VLOG-L or HGL + a LUT allow you to compress a wide DR into a (pleasing) image with less stops than were captured.
-- Could camera manufacturers provide such a profile out of the box? Yes. (They already try to do so. Cine-D, is an example.) Will they make a really good one? Probably not. See above.
 
One second he’s talking about OLED, the next, he’s talking about an LCD screen: which is it? He repeats “12 stops” over and over, but in the first place, the GH5 is not even capable of twelve stops of usable dynamic range in HLG, and in Natural, it’s much less than that. Rec709 absolutely does not contain 12 stops of dynamic range, so it is impossible to shoot 8-bit rec709, play with the brightness levels on a tv set, and magically double the dynamic range. If 10-bit HLG has, say, 10 usable stops of DR, I think we can safely say that the Natural photo style Vesku shoots has no more than 8 stops. Rec709 is capable of around 6 stops maximum from everything I have seen and read, which is far from being HDR compliant. Finally, even if his Panasonic television is able to reproduce a cinema color gamut, it can never increase what color was never there in the rec 709 file. I should add that Vesku further confuses the issue by referring to HDR in earlier posts, since this thread is not even about HDR - it’s about shooting HLG, converting it to rec709 and using the Leeming LUT in order to get the best tonality and color the GH5 is capable of - when viewed on an SDR display. And SDR displays are able to reproduce at most 6-7 stops of DR.
 
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jonpais said:
And SDR displays are able to reproduce at most 6-7 stops of DR.
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Yes, according to spec SDR displays are able to produce a maximum of 6-7 stops of luminance dynamic range.

...But many new sets that are being sold that fall somewhere between the SDR and HDR specs, and many people are buying HDR sets to watch SDR content. Most of these consumer sets will not be calibrated for SDR playback, so the actual display might be showing 10+ stops of luminance between it's lightest and darkest display pixels. ( and some might be artificially "stretching" the SDR dynamic range to fit the HDR display modes )

From what I've seen with my own eyes wandering around a BestBuy with a large mixture of SDR and HDR 55 - 75 inch TV sets, many of the HDR sets are making SDR content look better. ( "blacker" blacks and "whiter" whites, with smoother color gradation than the SDR sets do with the same SDR content )
 
It is possible to grade an 8-bit image to look better on an HDR display. But to assert that someone can squeeze 12 stops of dynamic range out of the Natural profile on a GH3 that nearly resembles HDR? I think there is some confusion here between what the sensor is capable of and how compression affects the image. Also, this topic is not about HDR, it is about working with HLG in rec709. At the risk of repeating myself, it is impossible to get twelve stops of usable DR shooting any profile with the GH5, let alone with Natural. This analogy is probably flawed, but it's like recording a symphony orchestra with a microphone only capable of reproducing tones from 1,000hz -10,000hz and boosting treble and bass with an equalizer - it can't be the same as a microphone that captures tones from 20-20,000hz. Finally, it is all but impossible to compare displays on a showroom floor: you must first disable all enhancements, then view the image in a darkened room.
 
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GH5 HLG is a HDR profile. It records larger color space and DR than GH5 "normal" profiles. I think GH5 Standard profile contrast 0 is close to standard look of rec709. It is quite contrasty in good TV with clipped HL and dark blacks. When using flatter profiles and image adjustments the image goes away from standard recommended rec709 colors and DR. CineD contrast -5 and idynamic is very flat, almost like a log. It records more DR and color space than Standard contrast 0. Is it 10, 11or 12 stops is a bit subjective. How much noise is in shadows and how much good NR can affect "usable DR".

The GH-series has got more DR with every generation. If someone says GH5 has 8 stops, then GH4 has 7.5 stops, GH3 7 stops, GH2 6 stops. I am sure GH2 has more than 6 stops. GH2 has excellent DR compared to small sensor camcorders.

I wonder if someone has tested what are the recorded color spaces of GH5 profiles compared to standard rec709. In fact what is exactly the rec709 standard? Is there some good rules for grading rec709? Rec709 is a display standard but almost all modern displays exceed the rec709. How crushed the blacks must be in good rec709 grade? Why some cameraA rec709 video clips highlights much more than cameraB?
 
A question for Paul or someone else:

How the GH5 HLG records image. What kind of curve and color adjustments we must do to make HLG look normal rec709? It is hydrid log gamma. So it combines LOG and GAMMA but how? What about colors, must I boost saturation too with curve adjustment?

I would like to play GH5 HLG video with a player (Potplayer, MPC-H) using a LUT or curve so that the video looks good in bright SDR TV. Is it possible? Can I use Pauls Leeming LUT with a player?

I have shooted some HLG clips and watched with Potplayer/good TV. When I adjust TV contrast 100, brightness 100 and saturation 80 with panel native gamut 98% of DCI-P3 the HLG video looks almost normal and with stunning clarity and shiny reflections. A HDR TV also maxes adjustments when playing HDR. The tone curve is still different so my SDR TV cant show accurate colors/curve.

I will buy a HDR OLED TV in future. Has anyone tried GH5 HLG clips with HDR OLED straight from SD card or with 10bit computer system?
 
https://en.wikipedia.org/wiki/Hybrid_Log-Gamma

You don't need to do anything to watch HLG footage on a SDR display, that's kind of the beauty of it. If you want to make a curve that compresses that log portion of the curve into the SDR range, then there's no one "right" way to do so...just use Resolve or some other app that allows you to play with the curve and output a LUT.
 
jonpais said:
it is impossible to get twelve stops of usable DR shooting any profile with the GH5
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According to Panasonic the GH5 using the V-Log L profile captures video with 12 F-stops of dynamic range.

According to the DXO folks, the GH5 camera captures 13 F-stops of dynamic range when shooting still photos.
 
TheDingo said:
According to Panasonic the GH5 using the V-Log L profile captures video with 12 F-stops of dynamic range.

According to the DXO folks, the GH5 camera captures 13 F-stops of dynamic range when shooting still photos.
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The bottom 2-3 stops are unusable due to noise though - usable DR is what we need to be talking about.
 
Shirozina said:
The bottom 2-3 stops are unusable due to noise though - usable DR is what we need to be talking about.
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What I would like to see is some independent real-world (no charts) side-by-side comparisons of the same scenes shot under the same conditions, so that we can actually put an image to these discussions of dynamic-range and noise, because it seems like everybody has a slightly different experience with these things.

I know for myself the GH5 was a huge step up from the GH4 in terms of color and a small step up from the GH4 in terms of dynamic range. The color has been so much better that I only want to use 10-bit recording for everything I shoot in the future, so I'm hoping that we see some affordable ENG cameras with 4K 10-bit internal recording. ( a DVX200 upgrade would be nice )
 
Shirozina said:
The bottom 2-3 stops are unusable due to noise though - usable DR is what we need to be talking about.
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That is absolutely not true. Care to post some examples of this? Plenty of other professionals out there getting a clear 12 stops out of the GH5.
 
Vesku, the footage from the camera in HLG needs to be converted to work properly on Rec709 displays, hence the topic of the thread and my LUT, which does exactly that. The LUT alters the curve and colorimetry to correctly display the footage while using all the recorded dynamic range, without clipping anything.

You ask how to convert HLG to Rec709.... the answer is my LUT :) Apply it to your HLG footage as per this guide and you're done. No other changes needed.

HTH

Paul :)
 
‘plenty of other professionals say’. ‘according to Panasonic’. ‘according to DXO’. Firstly, RAW stills is no indication of video performance. Secondly, manufacturers regularly exaggerate: even ISO 1600 is not ISO 1600 on the GH5. Lastly, ‘real world tests’ aren’t repeatable, which is why labs rely on Imatest. And while Imatest shows that the GH5 sensor does indeed capture over 10 stops of dynamic range, just how much of that dynamic range is usable will depend on such things as proper exposure, and how much noise the photographer is willing to accept. Those who wish to see comparisons showing how much detail can be pulled out of the shadows and highlights can probably find them on Max Yuryev’s YT channel. But I really don’t know why photographers get all hung up on numbers. I don’t do power windows, I never shoot scenes with over ten stops of dynamic range, and in my entire life, I’ve never lifted the shadows. But again, we’re way off topic here. If anyone wants to debate dynamic range or discuss shooting HDR and OLED televisions, they should start a new topic.
 
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visceralpsyche said:
Vesku, the footage from the camera in HLG needs to be converted to work properly on Rec709 displays, hence the topic of the thread and my LUT, which does exactly that. The LUT alters the curve and colorimetry to correctly display the footage while using all the recorded dynamic range, without clipping anything.

You ask how to convert HLG to Rec709.... the answer is my LUT :) Apply it to your HLG footage as per this guide and you're done. No other changes needed.

HTH

Paul :)
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HLG looks recording dark tones as a normal rec709 standard profile but lifting quite much mid and light tones. I want to play HLG with my "almost HDR but still SDR" TV. Is there a way to use your LUT with a player? Can an editor play GH5 10bit HLG files with your LUT from time line smoothly. My PC Potplayer plays 10bit HLG HEVC smoothly but 10bit HLG h.264 stutters and drops frames.
 
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