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Discussion Starter #1
Here are two sample HLG clips shot by the GH5. Default exposure was used for these clips and no editing was performed.


 

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Watching both clips on my garden variety Rec.709 12.2" 1440p tablet display in YouTube app they look OK to me. The color balance and gamma don't look ideal of course but to be honest look no worse than those contrived grading looks in countless online videos from raw non-HLG log gamma footage I have seen so far.

The colors here seem a bit compressed compared to the colors in regular Rec.709 videos but this is hard to tell precisely because I have no idea how the actual scenes looked. The DR seems compressed as well but nowhere near the distinctly wash-out looks I normally see in ungraded log gamma footage on regular Rec.709 monitors. Though my tablet has no waveform display but judging by the look of it the highlights seem to be contained within the 100 IRE threshold while the darkest shadows look safely above 0 IRE with some details still visible.

Will play with them some more on my computer when I get back home. Would be interesting to see how this baked-in HLG clips look on my calibrated monitor in both Rec.709 and Rec.2020 color space. I have a feeling they wouldn't look too bad (or too wrong).
 

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Discussion Starter #4
The colors open up dramatically when actually played on an HLG capable display, but viewing on my computer monitor, I can definitely see why you'd call the colors a bit 'compressed'. No compression that I can see when shown on my HLG displays. However to my eyes the darker areas seem a bit too dark, but that's the same thing I tend to see when watching typical HDR. When the darker areas are compensated for, the brighter areas tend to blow out on the professional HDR10 productions I've seen. I really haven't played with this much, but I will in the future.

As I've said, I think there's a real art to shooting and grading HDR that actually adds to the viewing experience and doesn't make you say, "Oh, they're trying to hit me over the head that this was shot in HDR". IMO this should border on being transparent to the viewer. If it calls attention to itself, it may not have been done properly.

But as I've said, it's really fun that the GH5 makes this such an effortless process when displayed on a HLG display. :)
 

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Here is a screenshot off my 28" Dell 4K monitor without HLG and an adjusted screenshot on Flickr. I guess a HLG screenshot would look somewhat like that.

 

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Discussion Starter #6
Joe, thanks for that, but in actuality it looks much better on my HLG enabled OLED than your corrected pix. The colors are much more natural in the HLG version.
 

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Joe, thanks for that, but in actuality it looks much better on my HLG enabled OLED than your corrected pix. The colors are much more natural in the HLG version.
Of course the shot looks better in hlg (it better be true).

How about the same scene shot using hlg and then the settings you usually use? That is the issue - how much worse viewed on a normal screen the hlg video is than if shot normally.
 

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Discussion Starter #8
It is true.

I will try your exercise tomorrow. Obviously the 'normal' shot will look considerably better than the HLG shot on a non-HLG display. So at least to me, this is somewhat of a pointless exercise, but I'll play.

True the HLG looks better on a non-HLG display than ungraded Slog/Vlog, but neither looks great. I wouldn't condemn non-graded Slog/Vlog on a display any more than I would HLG on a non-HLG display. HLG obviously needs a targeted display.
 

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It is true.

I will try your exercise tomorrow. Obviously the 'normal' shot will look considerably better than the HLG shot on a non-HLG display. So at least to me, this is somewhat of a pointless exercise, but I'll play.

True the HLG looks better on a non-HLG display than ungraded Slog/Vlog, but neither looks great. I wouldn't condemn non-graded Slog/Vlog on a display any more than I would HLG on a non-HLG display. HLG obviously needs a targeted display.
No. Vlog and slog can be converted to rec709 to look good on regular screens. Hlg video is very difficult, if not impossible, to convert to look good on rec709 screens. The idea is that, as is, it does not look that bad on rec709 screens, so let's see. This is not a game, it's a major issue of this new standard for HDR.

Let me say it again: hlg is a delivery profile for viewing only and not meant for conversion. Vlog and slog are shooting profiles not meant for display at all but for grading. No one displays RAW slog or vlog on any screen, but the claim is that hlg looks ok on non HDR screens. So lets see.

Thanks for your efforts on this; it is not at all a GH5 issue, as Sony is offering the same option as is Atomos.
 

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Discussion Starter #10
To be clear, if you read what I said, I stated, “True the HLG looks better on a non-HLG display than ungraded Slog/Vlog, but neither looks great. I wouldn't condemn non-graded Slog/Vlog on a display any more than I would HLG on a non-HLG display. HLG obviously needs a targeted display.”

Yes, I understand that Vlog/Slog are not intended for viewing without grading. Obviously.

With that said, I can assure you that HLG on a non-HLG display will not look great and I have no idea who is claiming otherwise. It is NOT intended for viewing on a non-HLG display and Panasonic has not said otherwise.

I can only say what I said before, it will look better than RAW Slog/Vlog...and again, yes, RAW is not intended for ungraded viewing. I’m simply trying to put things in perspective since most of us know what ungraded Slog looks like.
 

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To be clear, if you read what I said, I stated, “True the HLG looks better on a non-HLG display than ungraded Slog/Vlog, but neither looks great. I wouldn't condemn non-graded Slog/Vlog on a display any more than I would HLG on a non-HLG display. HLG obviously needs a targeted display.”

Yes, I understand that Vlog/Slog are not intended for viewing without grading. Obviously.

With that said, I can assure you that HLG on a non-HLG display will not look great and I have no idea who is claiming otherwise. It is NOT intended for viewing on a non-HLG display and Panasonic has not said otherwise.

I can only say what I said before, it will look better than RAW Slog/Vlog...and again, yes, RAW is not intended for ungraded viewing. I’m simply trying to put things in perspective since most of us know what ungraded Slog looks like.
RAW video files cannot be displayed on any TV at all. Slog files are not RAW, but I get what you mean.

So, if HLG files do not look very good on non HLG displays (we will see how bad), which is what most people have, and HLG files cannot even be edited to ever look good on a non HLG display, why would anyone want to shoot using HLG and be locked in to that specific standard forever? I can see making an HLG video from Slog or Vlog, but it just seems nuts to ever shoot that way except to have a little fun once in a while. I get it, it was a free upgrade so why not have fun?

Btw, my TV was just upgraded through an update to play HLG. And my Shogun Inferno was updated to record HLG from RAW. So, HLG is now a common HDR standard.
 

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With that said, I can assure you that HLG on a non-HLG display will not look great and I have no idea who is claiming otherwise. It is NOT intended for viewing on a non-HLG display and Panasonic has not said otherwise.
Yes it is intended for viewing on non-HLG displays. It's also wrong to say HLG is not intended for grading. Certainly it's less necessary to grade it than regular log gammas like SLog2/3 or VLog but it absolutely benefits from it.

It's wrong to conclude everything about HLG just from what is seen straight from the camera. Check out this HLG video from LG. It looks fantastic in SDR.

HLG is after all, regular SDR in the lower half of the gamma curve, and log gamma in the upper half, thus hybrid. I would bet if you would tweak the HLG image with in-camera settings where it looked the best it can be in SDR, it would be even better in HLG, instead of trying to do it the other way around.
 

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Just tried watching Ken's clips again now on the Sony Xperia XZ Premium's 5.5" 4K HDR screen set to "Standard". They now looked way better and probably more accurate than they did on my older and non-HDR Samsung tablet screen.

There was much better distinction among the fall foilage colors and also among the different shades of greens in the trees and grass at the bottom. The sky was bluer too. What Tom says makes sense since the overall gamma level appeared to be more or less correct with nicer, more vibrant colors, and highlights, midtones and shadows looking natural without clippings or being flattened.

I don't know if the HLG meta-data were somehow tagged onto the clips to flag a capable display device such as the one on the XZ Premium or the tagging was built into the YouTube app so that the same display that can play both HLG and regular Rec.709 can display both kinds of videos correctly without the viewers having to make any adjustments.

It looks to me if you have an HLG or HDR capable viewing device and you watch the materials via the YouTube app, things are all rosy and effortless. If you don't, the results can be varied though not to the extent of ungraded log gamma videos. But what I really want to find out is how much we can do in post to get HLG videos like Ken's to look as close to normal as they can on standard non-HLG or non-HDR viewing devices. Or if it can't be done?
 

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Discussion Starter #14
RAW video files cannot be displayed on any TV at all. Slog files are not RAW, but I get what you mean.

So, if HLG files do not look very good on non HLG displays (we will see how bad), which is what most people have, and HLG files cannot even be edited to ever look good on a non HLG display, why would anyone want to shoot using HLG and be locked in to that specific standard forever? I can see making an HLG video from Slog or Vlog, but it just seems nuts to ever shoot that way except to have a little fun once in a while. I get it, it was a free upgrade so why not have fun?

Btw, my TV was just upgraded through an update to play HLG. And my Shogun Inferno was updated to record HLG from RAW. So, HLG is now a common HDR standard.
You miss the point that if you’re shooting for your own use and your own viewing, then it can make perfect sense to shoot in HLG. Mark, most of what I shoot and I suspect much of what many others shoot, is not necessarily uploaded for the world to see. Quite the contrary.

At this point I have no idea how much I’d shoot in HLG and to be honest, I have no idea how it looks on a non-HLG TV. I’ve only seen it in its SDR form on my IMac, but never on a SDR TV (I don’t have any, but I’ve yet to see if I can manually turn off the HLG function of my OLED). According to Tom, it can be made to look quite good. If so, your compatibility argument goes out the window.
 

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Discussion Starter #15 (Edited)
Yes it is intended for viewing on non-HLG displays. It's also wrong to say HLG is not intended for grading. Certainly it's less necessary to grade it than regular log gammas like SLog2/3 or VLog but it absolutely benefits from it.

It's wrong to conclude everything about HLG just from what is seen straight from the camera. Check out this HLG video from LG. It looks fantastic in SDR.

HLG is after all, regular SDR in the lower half of the gamma curve, and log gamma in the upper half, thus hybrid. I would bet if you would tweak the HLG image with in-camera settings where it looked the best it can be in SDR, it would be even better in HLG, instead of trying to do it the other way around.
Tom, not according to Panasonic. In fact when you switch to the HLG mode on the GH5, you get a clear prompt that cautions you that this is intended for playback on a HLG-enabled TV. Yes, it doesn’t say it ‘won’t’ play on a SDR TV, but it clearly states that the target display should be a HLG capable display.

As to the lack of grading capabilities of HLG, that wasn’t my claim, but rather Mark’s. Personally I have no idea, but I’ll take your word for it.

However this brings up an interesting question. If you grade HLG for optimum SDR playback, aren’t you then compromising optimum HLG playback? How do you simultaneously grade for both? I can only assume you need to make two separate edits.

Edit: Tom, looking at that LG video on my IPad, you’re right, it looks great in SDR. Later I’ll take a look at this on my OLED, but I’m not sure the YouTube app is HLG enabled.
 

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Discussion Starter #16
Just tried watching Ken's clips again now on the Sony Xperia XZ Premium's 5.5" 4K HDR screen set to "Standard". They now looked way better and probably more accurate than they did on my older and non-HDR Samsung tablet screen.

There was much better distinction among the fall foilage colors and also among the different shades of greens in the trees and grass at the bottom. The sky was bluer too. What Tom says makes sense since the overall gamma level appeared to be more or less correct with nicer, more vibrant colors, and highlights, midtones and shadows looking natural without clippings or being flattened.

I don't know if the HLG meta-data were somehow tagged onto the clips to flag a capable display device such as the one on the XZ Premium or the tagging was built into the YouTube app so that the same display that can play both HLG and regular Rec.709 can display both kinds of videos correctly without the viewers having to make any adjustments.

It looks to me if you have an HLG or HDR capable viewing device and you watch the materials via the YouTube app, things are all rosy and effortless. If you don't, the results can be varied though not to the extent of ungraded log gamma videos. But what I really want to find out is how much we can do in post to get HLG videos like Ken's to look as close to normal as they can on standard non-HLG or non-HDR viewing devices. Or if it can't be done?
That was precisely my point in an earlier post.

In the end, the effortless nature of HLG will be a significant attraction for many. HLG is not going away and will be much more common in the future.
 

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Discussion Starter #17 (Edited)
So an update on the YouTube HLG video that Tom linked to from LG.

I watched it on my HLG-enabled OLED, and the clip played in SDR. It did look excellent, but the 'HLG' logo in the upper right of my OLED, never lit up. So this could be due to a couple of things. First, the video may not have been flagged for HLG and thus my display never kicked into the HLG mode as it does with my HLG GH5 clips.

Second, the YouTube app itself on my OLED may not have HLG capability, even though it does have HDR capability as evidenced by the many YouTube HDR clips I can play on that app. I tried this on my Nvidia Shield Pro, but it is not enabled for any form of HDR at the current time. Nvidia promises an upgrade in the future, but I have no idea what form of HDR it will eventually be compatible with.

After playing a number of HDR clips on YouTube, from a variety of sources, and then going back to my HLG clips from the GH5, I'm actually more impressed than I was before with the GH5's HLG. It's truly amazing that I can get these results with virtually no effort. I haven't even tried to optimize things, so I'm reasonably confident I can further improve results with the in-camera settings. :)

Edit: Scratch possibility #2 above. I just checked my posted HLG clip from YouTube, and the HLG logo lights up in the upper right of my OLED. So the LG OLED's YouTube app is indeed HLG capable. That leads me to believe the LG clip that Tom linked to is simply not carrying an HLG tag or its tagged improperly.
 

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Let's cut the babble and just get two video versions of the same scene

1. Let's see an outdoor scene whose colors and DR we can relate to, rather than an artificially lit club scene like in the above video - clearly the colors in that are quite odd, and not intended to be anything but. Its a neat video. But looking good and being accurate are not the same. We want to know the disparity between what the scene looks like and what HLG viewed in REC709 provides.

Ken: show us the two shots, and we can all decide. We can trust your regular shot will be as accurate as can be.

2. HLG is not just a different gamma curve, it is also a difference color gamut. Translating that color gamut to REC709 is another challenge for trying to make HLG video look good on REC709 viewers by grading.

3. No one has claimed you cannot grade HLG video - you can grade any video. The issue is whether it can be graded to attain the same optimized REC709 look as one would have gotten shooting REC709. And, especially compared with going from Slog/Vlog to REC709.

4. When you are shooting HLG, what you see in the viewfinder is the REC709 version, since the camera display is not HLG. That will make adjusting exposure and any color controls while shooting to difficult to judge. The same is true of Vlog or Slog, except now many cameras have a viewing LUT to transform the Slog/Vlog to REC709. In principle that could be done for HLG, but I don't see that available.

5. By design, HLG provides less dynamic range than Slog/Vlog. Its hybrid gamma is a compromise, and some indeed have made the claim that HLG can look good on REC709 screens. No one claims it will look just as good as a REC709 shot - so, again, lets see the difference.

6. And, to repeat, if you shoot in Vlog/Slog you can make HLG or HD10 HDR videos and SDR videos without compromise (yes, two renders).

7. Having an in-camera HLG option is better than not having, but everyone should be aware of its limitations.
 

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Discussion Starter #19
Mark, lots of good posts here and some quite informative, no babble that I've read. As for the clip Tom linked to, who said anything about 'accurate color'. This was simply supposed to be an HLG clip from LG. Nothing more nothing less.

At any rate no HLG today with the rain. This will be done on a sunny day. So until then, enjoy the 'babble'.

Oh, and no, I'm going to try to 'doctor' the SDR clip to try to make the HLG clip look as good as it can, just as I carefully showed only the zooming AF clips from the RX10iii that didn't screw up the focus. :rolleyes: :rolleyes:
 
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