HDR is crayons

[StingingVelvet]

Originally Posted by Ruined

If you try to watch HDR on a 50nits display, 100 nits display, etc, without tonemapping it will be dark and unwatchable.

That's not his point. His point is that no matter the wrapper, HDR doesn't need to be used at high nits to be effective. Goodfellas comes in a 4,000 nit HDR wrapper I believe, but it's brightest moment is like 250 nits. It's using HDR in a very respectful and accurate way to expand the range on the low end and look like a film print, without flashy revisionism. In my experience the majority of catalog movies shoot for this kind of look, with very few explosions of light.

You and a few others, who want to ditch HDR entirely, are missing how well and respectfully it can be used. You're equating all HDR with X-Men Apocalypse style pizzaz. That stuff can be fun, but honestly the best thing about HDR... and the UHD format, really... is the subtle use of HDR to improve contrast, detail, color and depth in even the lowest nit scene.

[MisterXDTV]

Originally Posted by StingingVelvet

That's not his point. His point is that no matter the wrapper, HDR doesn't need to be used at high nits to be effective. Goodfellas comes in a 4,000 nit HDR wrapper I believe, but it's brightest moment is like 250 nits. It's using HDR in a very respectful and accurate way to expand the range on the low end and look like a film print, without flashy revisionism. In my experience the majority of catalog movies shoot for this kind of look, with very few explosions of light.

You and a few others, who want to ditch HDR entirely, are missing how well and respectfully it can be used. You're equating all HDR with X-Men Apocalypse style pizzaz. That stuff can be fun, but honestly the best thing about HDR... and the UHD format, really... is the subtle use of HDR to improve contrast, detail, color and depth in even the lowest nit scene.

Too bad most studios don't use it that way....

[StingingVelvet]

Originally Posted by MisterXDTV

Too bad most studios don't use it that way....

I think they do, for catalog material. Sony is kind of the exception, and Universal on a couple titles (The Mummy, King Kong). Overall though? I think it's used in a restrained way on older movies.

[nick4Knight]

For mine the burning issue is the word revisionism being spuriously used by some. When it's totally absurd to state that revisionism of classics = automatically bad.

a) There can be GREAT revisionism; in the sense that the filmmakers never intended highlights -present on the film stock- to be presented to audiences as it does on a UHD; but in the case of Bridge on the River Kwai it was impressively handled pretty much by consensus?

b) There can be BAD revisionism; which would be like taking the Lawrence of Arabia scan and making it compete with Ridley Scott's Exodus HDR grade?

It kinda is that simple. Until they start to make alterations (as opposed to allowances) like example 2, stop demonising the studios for using HDR.

[Ruined]

I have no problem with revisionism or revisionist HDR, often the revisionist version looks more pleasing IMO.

But people I think are fooling themselves when claiming HDR was original intent on older movies, its simply not possible with the theatrical target of the time; and given that point, I can see why purists like RAH would prefer to use SDR.

As I said earlier in the thread, the best solution is offering both 4k HDR and 4k SDR grades especially for classic evergreen movies that are going to sell enough to cover the costs. Maybe raise MSRP by $10 on releases like this.

[tama]

I love Crayons

[LoSouL]

I think this post needs to be on this page once again:

Originally Posted by Deciazulado

Well the debate rages on. Less is More vs More and then Some


Submitted for your consideration:

Color:

Color film (negative and print) and digital cameras have a wider gamut of color than SDR 709. Color on film which is out of the 709 bounds has to be clipped or reduced.

Posted some of these before.
This first one, the link to the measured film colors image on Bruce Lindbloom's site from years ago is not working anymore but I found the image on my hard drive where I had added some color space triangles to it, I think they are the 709/P3 or NTSC/2020 triangles transformed to the D50 illuminant that these film color points are measured with:



(Triangle is Adobe1998, whose red and blue are equal to 709, but green is the 1953 NTSC original green which lies between the P3 green and 2020 green). From https://www.photo.net/discuss/thread...f-film.464422/.







Sony F65


You can see the SDR 709/sRGB space is rather limiting

Levels/Values:

PQ 12-bit: 3760-256 = 0-3504, 3505 values from 0-10,000 nits;  
                      0-1780, 1781 values from 0-100 nits 
PQ 10-bit:   940-64 = 0-876,   877 values from 0-10,000 nits;
                      0-445,   446 values from 0-100 nits
8-bit gamma: 235-16 = 0-219,   220 values from 0-100 nits

Deep shadow detail:

For 8-bit 2.2 gamma:

0 = 0% black = infinite black
1 = -17.1 f/stops darkest gradation discernible from total black

For 8-bit 2.4 gamma:

0 = 0% black = infinite black
1 = -18.7 f/stops darkest gradation discernible from total black
2 = -16.3 f/stops second gradation discernible from black, a + 2.4 stops change
3 = -14.9 f/stops third gradation discernible from black, a + 1.4 step
219 = 100% = -0 f/stops (100 nits)

For PQ 10 bit

0 = 0% black = infinite black
1 = -21 f/stops darkest gradation discernible from total black
2 = -19.2 f/stops second gradation discernible from black, a + 1.8 step
3 = -18.2 f/stops third gradation discernible from black, a + 1.0 step
4 = -17.4 f/stops +0.8 step
5 = -16.9 f/stops +0.5 step
6 = -16.4 f/stops +0.5 step
7 = -16.0 f/stops +0.4 step
8 = -15.6 f/stops +0.4 step
9 = -15.3 f/stops +0.3 step
10 = -15.0 f/stops +0.3 step
11 = -14.8 f/stops +0.2 step
445 = 50.8% = -0 f/stops (100 nits)
876 = 100% = + 6.6 f.stops (10,000 nits)

I've color coded the brightness levels common to both so you can compare and you can see that apart of going deeper, in HDR the gradation of tones has 3-5 times more steps between tones than SDR.
For SDR to have this quality you have to limit shadows to be higher in the range.

For PQ 12 bit:

0 = 0% black = infinite black
1 = -24.3 f/stops darkest gradation discernible from total black
And 4 times finer gradation steps than 10-bit PQ has. (No, I'm not gonna calculate those)


Step discrimination:

Under the thresholds you don't see steps. I couldn't find one chart with 100nit SDR 8-bits on the pdfs so I recalculated from 10b and 12b 1k nit and 10k nits SDR graphs.

(Probably the last few shadows, in the low level f/stops, in SDR could end up looking "grotty" when unveiled on high contrast/deep black displays if they weren't evaluated on such when mastering.)



Range summary:

8-bit 2.2 gamma: From step 1 = -17.1 f/stops to + 0  f/stops above 100 nits
8-bit 2.4 gamma: From step 1 = -18.7 f/stops to + 0  f/stops above 100 nits
10-bit PQ:       From step 1 = -21.0 f/stops to +6.6 f/stops above 100 nits
12-bit PQ:       From step 1 = -24.3 f/stops to +6.6 f/stops above 100 nits

Since SDR has no highlight headroom (unless you use above range video values from 236-255, a + 0.3 f/stop difference at gamma 2.4, less at 2.2) the diffuse white value is usually set lower in SDR than 100 nits, therefore reducing further the f/stops available for the shadows.


Highlights headroom:

As per above SDR has no highlight headroom above 100nits. HDR has +6.6 f/stops


What about film

Checking the spec sheets I see:

15.5 f/stops, + ~ 1.3 f/stops of lens flare shadow "compression" = 16.8 f/stops recorded onto = 2.1 dLog density neg,


printed to 5.3-5.4 dLog density (17.7-18 f/stops) in Premier prints, but only onto 3.8 dLog density (12.7 f/stops) on the other print stock.

Which smacks of print revisionism! j/k

What I mean, you have to have a perfectly preserved unfaded reference original print or have seen it, and watched it in the same illuminant it was projected in, or have the exact print stock tech sheet and detailed notes on how the print was developed and the negative was to be printed (printer lights) for each scene originally, and be able to reproduce a LUT table from them, and the negative is well preserved too, to get exactly how the film "looked". Sometimes as best approximate it as closely as possible with the technology, materials and tools at hand, sometimes using your best subjective interpretation.

You can always abuse a tool but a better tool lets you do a better job.

UHD HDR 2160p x PQ x 10 bit x 2020 has less limitations than SDR.

[Show spoiler]

[Deciazulado]

Originally Posted by MisterXDTV

Try watching HDR on a 100 nits LCD, you will see darkness....

like this

10000nit

[Deciazulado]

Originally Posted by Ruined

If you try to watch HDR on a 50nits display, 100 nits display, etc, without tonemapping it will be dark and unwatchable.

OLED must be magical

:>

turning down OLED Light and player/display Contrast in a dark room so that 1000 is 100 or 50, -2.8 to - 3.3 doesn't cause hair nits

[Ruined]

Originally Posted by Deciazulado

OLED must be magical

:>

turning down OLED Light and player/display Contrast in a dark room so that 1000 is 100 or 50, -2.8 to - 3.3 doesn't cause hair nits

Eh? The TV is going to dynamically tonemap the image to whatever brightness you have the display setup for; at least if the the tonemapping algorithm is any good that's what it would do. That's one big disadvantage projectors have as unlike TV, projector has no idea how bright the screen is, since screen can vary in size, gain, etc, unlike a TV screen which remains same at all times.

[Deciazulado]

This has become a strange debate.

For years we had people complaining that SDR and BD could not reproduce the gamut and tonal and dynamic range of film, then when we get a format that can and then some, people argue and shoot it down. Ditch it! let’s stick with SDR, film is not HDR. Revision reVISION!

Like I said in some tiny post of mine, just checking the tech sheets I can see at least ~17 f/stops of range possible/captured for the original image on film and prints capable of up to 18 f/stops.

I don’t readily have tech sheets for other films but mmm density and silver and all that jazz it’s ancient tech, just check Ansel Adams or Photographic Materials and Processes by Compton, Stroebel et al. But doing a quick search for old print densiity I got this post by Edgar Njari

Originally Posted by Edgar Njari

Hi everyone.

I would just like to inform you about a certain test that Kodak
did on one of their motion picture films (vision 500T 5279).
the test included photgraphing shiny metal spheres that reflect
very bright highlights. The tests confirmed that there were
variations recorded 15.9 stops above 18% gray, which gives film
a dynamic range of about 20 stops.

I can't provide you with any links because the tests are described in
some SMPTE documents, which require SMPTE membership.
But here is a link to a post from John Pytlak from kodak that
explains it all.

http://www.cinematography.com/forum2...showtopic=2649

too bad the link doesn't work anymore & Pytlak is gone (RIP) but he always seemed he knew his stuff and explained it well.

And for prints this Gray-Scale Transformations of Digital Film Data for Display, Conversion, and Film Recording (from 1993) which shows a range of 3.25-4 (2000:1 to 8000:1, 11 to 13 f/stops) for prints and of course after that with Vision it's up to to 5.5 (250,000:1, 18 f/stops)

May I remind you that the normal way of viewing movies at home for the last decade for most people was with average LCDs with maybe 1000:1 contrast if good (a 10 f/stop range) (People and masterers with CRTs and Plasma excluded) and BDs, all in in 8bits, which I’ve said possibly could end a bit grotty if doing extremes of higher f/stops contrast ranges? Videophiles demanded darker, truer “cinema” blacks and we got LCDs with better panels, OLEDs, and Irises. And HDR, all driving to the same point: Have a higher dynamic range so the filmic images weren’t constrained and we can see them fully.

So where is this notion than prints (with 11-13 f/stops range and up to 18 in more contemporary times) aren’t HDR and are actually SDR, just because they are displayed at 50nits, coming from; and therefore the HDR video format is unnecesary at best and an abomination at worst?

I know the argument of “You could radically change the intent!”, but that thing is not part of “NO HDR is GOOD HDR cus film in a theater is …”

[Deciazulado]

Originally Posted by Ruined

Eh? The TV is going to dynamically tonemap the image to whatever brightness you have the display setup for; at least if the the tonemapping algorithm is any good that's what it would do.

I don't let it. I adjust it so I get the curve, just dimmer. Of course I don't watch in 50 nits (-3.3 f/stops darker) but if I do, there's still 15 f/stops or more of shadow range under that, which is more than a 1000 nit LCD with 16,000:1 contrast

[Ruined]

Originally Posted by Deciazulado

This has becoming a strange debate.

For years we had people complaining that SDR and BD could not reproduce the gamut and tonal and dynamic range a of film, then when we get a fortmat that can and then some, people argue and shoot it down. Ditch it! let’s stick with SDR, film is not HDR. Revision reVISION!

...

I know the argument of “You could radically change the intent!”, but that thing is not part of “NO HDR is GOOD HDR cus film in a theater is …”

I'm not saying ditch HDR, but to claim its not revisionism is a bit unbelievable. Filmmakers 20+ years ago didn't shoot their films and grade them for 4K UHD HDR home media on a Samsung QLED display. They shot and graded them for theatrical exhibition, which was nowhere near HDR at that time. Therefore its essentially impossible to claim anything remotely approaching HDR was a filmmakers original intent for an older movie.

Its fine to have a revisionist HDR presentation, but I think like RAH is advocating for having a less revisionist SDR presentation would be additionally nice as well. Making an ultra conservative HDR presentation seems like a waste, too, as you could avoid tone mapping altogether (and hence increase accuracy across all displays) with an SDR grade.

[HeavyHitter]

Originally Posted by Ruined

I'm not saying ditch HDR, but to claim its not revisionism is a bit unbelievable. Filmmakers 20+ years ago didn't shoot their films and grade them for 4K UHD HDR home media on a Samsung QLED display. They shot and graded them for theatrical exhibition, which was nowhere near HDR at that time. Therefore its essentially impossible to claim anything remotely approaching HDR was a filmmakers original intent for an older movie.

Its fine to have a revisionist HDR presentation, but I think like RAH is advocating for having a less revisionist SDR presentation would be additionally nice as well. Making an ultra conservative HDR presentation seems like a waste, too, as you could avoid tone mapping altogether (and hence increase accuracy across all displays) with an SDR grade.

I'm not sure what RAH is asking. But he should know studios are never, ever going to release and SDR and HDR presentation on UHD BD. Why would they? 95% of the population want HDR and if you really need SDR, you have BD for better or worse. The time, resources, and money to make UHD BD discs with both SDR and HDR makes ZERO economical sense and would only drastically slow down UHD BD releases in general. Who needs that to happen?

[LoSouL]

What you intend to do and what you actually do are two different things.

All you're doing is making a case that theater projection was never capable of fully delivering what's captured on film.

[Geoff D]

Originally Posted by tama

I love Crayons

me too, couldn't eat a whole packet tho

[Ruined]

Originally Posted by HeavyHitter

I'm not sure what RAH is asking. But he should know studios are never, ever going to release and SDR and HDR presentation on UHD BD. Why would they? 95% of the population want HDR and if you really need SDR, you have BD for better or worse. The time, resources, and money to make UHD BD discs with both SDR and HDR makes ZERO economical sense and would only drastically slow down UHD BD releases in general. Who needs that to happen?

Not suggesting this for every release, but something like Spartacus that a lot of money is going to be put into for 4k resto and that will sell tons, why not have both SDR and HDR grades? RAH wants SDR only but I think a big evergreen movie like that it can be afforded to do both, and maybe sell a bit higher MSRP if needed. Then you could satisfy everyone, except those who want a budget priced release.

Heck maybe/likely the existing 4k resto is SDR since RAH did it? 1/2 done already then

[HeavyHitter]

Originally Posted by Ruined

Not suggesting this for every release, but something like Spartacus that a lot of money is going to be put into for 4k resto and that will sell tons, why not have both SDR and HDR grades? RAH wants SDR only but I think a big evergreen movie like that it can be afforded to do both, and maybe sell a bit higher MSRP if needed. Then you could satisfy everyone, except those who want a budget priced release.

Heck maybe/likely the existing 4k resto is SDR since RAH did it? 1/2 done already then

If HDR is applied, it will surely be very subtle. Most catalogs don't have it applied crazily at all.

But the Sparatus BD is like UHD-lite. Stunning BD with SDR for anyone that wants it.

[Ruined]

Originally Posted by HeavyHitter

If HDR is applied, it will surely be very subtle. Most catalogs don't have it applied crazily at all.

If its going to be very subtlety used, maybe even to near-SDR levels, in those cases why not just do an SDR grade and avoid the complexity of HDR mastering and display? Result will likely be more accurate and consistent across displays. I don't see a solid argument for HDR in these super-subtle theoretical usages other than for marketing purposes.

But the Sparatus BD is like UHD-lite. Stunning BD with SDR for anyone that wants it.

It is. I'm just saying, that BD you are complimenting was sourced from a 4K resto RAH himself did - it is very possible RAH did that resto in 4K SDR per his purist viewpoint. RAH may be trying to tell us that Spartacus 4K UHD is ready to go if the buying public would purchase a SDR 4K disc - which he also happens to feel is more accurate to the original intent.

[HeavyHitter]

Originally Posted by Ruined

It is. I'm just saying, that BD you are complimenting was sourced from a 4K resto RAH himself did - it is very possible RAH did that resto in 4K SDR per his purist viewpoint. RAH may be trying to tell us that Spartacus 4K UHD is ready to go if the buying public would purchase a SDR 4K disc - which he also happens to feel is more accurate to the original intent.

Perhaps. Or, it will be Marketing's call.