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What is HDR, anyway?

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Re: What is HDR, anyway?

#271

Post by smogcutter »

sandofsky wrote: post #252
dahart wrote: post #123

It seems like a mistake to lump HDR capture, HDR formats and HDR display together, these are very different things. The claim that Ansel Adams used HDR is super likely to cause confusion, and isn’t particularly accurate. We’ve had HDR formats and HDR capture and edit workflows since long before HDR displays. The big benefit of HDR capture & formats is that your “negative” doesn’t clip super bright colors and doesn’t…

> It seems like a mistake to lump HDR capture, HDR formats and HDR display together, these are very different things. These are all related things. When you talk about color, you can be talking about color cameras, color image formats, and color screens, but the concept of color transcends the implementation. > The claim that Ansel Adams used HDR is super likely to cause confusion, and isn’t particularly accurate. Th…

> Film negatives have 12-stops of useful dynamic range

No, that’s not inherently true. AA used 12 zones, that doesn’t mean every negative stock has 12 stops of latitude. Stocks are different, you need to look at the curves.

But yes most modern negatives are very forgiving. FP4 for example has barely any shoulder at all iirc.

Re: What is HDR, anyway?

#272

Post by lotrjohn »

theshackleford wrote: post #263
lotrjohn wrote: post #254

Earlier quoted context omitted.

Hello fellow CRT owner. What is your use case? Retro video games? PC games? Movies?

Hello indeed! > What is your use case? Retro video games? PC games? Movies? All of the above! The majority of my interest largely stems from the fact that for whatever reason, I am INCREDIBLY sensitive to sample and hold motion blur. Whilst I tolerate it for modern gaming because I largely have no choice, CRT's mean I do not for my retro gaming, which I very much enjoy. (I was very poor growing up, so most of it for…

> Outside of that, we have a "retro" corner in our home with a 32" trinitron.

A 32” Trinny. Nice. I have the 32” JVC D-series which I consider my crown jewel. It’s for retro gaming and I have a laserdisc player but a very limited selection of movies. Analog baby.

> Sadly though, as I get ready to take on a mortgage, it's likely most of my CRT's will be sold

Mortgage = space. You won’t believe the nooks and crannies you can fit CRTs into. Attic. Shed. Crawl space. Space under basement stairs. Heck, even the neighbors house. I have no less than 14 CRTs ferreted away in the house. Wife thinks I have only 5. Get creative. Don’t worry about the elements, these puppies were built to survive nuclear blasts. Do I have a sickness? Probably. But analog!!!

Re: What is HDR, anyway?

#273

Post by Sharlin »

brokenmachine wrote: post #260
Terr_ wrote: post #243

> Our eyes can see both just fine. This gets to a gaming rant of mine: Our natural vision can handle these things because our eyes scan sections of the scene with constant adjustment (light-level, focus) while our brain is compositing it together into what feels like a single moment. However certain effects in games (i.e. "HDR" and Depth of Field) instead reduce the fidelity of the experience. These features limp alo…

I'm with you on depth of field, but I don't understand why you think HDR reduces the fidelity of a game. If you have a good display (eg an OLED) then the brights are brighter and simultaneously there is more detail in the blacks. Why do you think that is worse than SDR?

The “HDR” here is in the sense of “tone mapping to SDR”. Should also be said that even “H” DR displays only have a stop or two of more range, still much less than in a real-world high-contrast scenes

Re: What is HDR, anyway?

#274

Post by Sharlin »

dahart wrote: post #123

It seems like a mistake to lump HDR capture, HDR formats and HDR display together, these are very different things. The claim that Ansel Adams used HDR is super likely to cause confusion, and isn’t particularly accurate. We’ve had HDR formats and HDR capture and edit workflows since long before HDR displays. The big benefit of HDR capture & formats is that your “negative” doesn’t clip super bright colors and doesn’t…

No, Adams, like everyone who develops their own film (or RAW digital photos) definitely worked in HDR. Film has much more DR than photographic paper, as noted by TFA author (and large digital sensors more than either SDR or HDR displays) especially if you’re such a master of exposure as Adams; trying to preserve the tonalities when developing and printing your photos is the real big issue.

Re: What is HDR, anyway?

#275

Post by 7bit »

Terr_ wrote: post #243

> Our eyes can see both just fine. This gets to a gaming rant of mine: Our natural vision can handle these things because our eyes scan sections of the scene with constant adjustment (light-level, focus) while our brain is compositing it together into what feels like a single moment. However certain effects in games (i.e. "HDR" and Depth of Field) instead reduce the fidelity of the experience. These features limp alo…

Ok. I like depth of field and prefer it.

Re: What is HDR, anyway?

#277

Post by brokenmachine »

Sharlin wrote: post #273
brokenmachine wrote: post #260

Earlier quoted context omitted.

I'm with you on depth of field, but I don't understand why you think HDR reduces the fidelity of a game. If you have a good display (eg an OLED) then the brights are brighter and simultaneously there is more detail in the blacks. Why do you think that is worse than SDR?

The “HDR” here is in the sense of “tone mapping to SDR”. Should also be said that even “H” DR displays only have a stop or two of more range, still much less than in a real-world high-contrast scenes

It's still better though.

HDR displays are >1000nits while SDR caps out at less than 500nits even on the best displays.

Eg for the Samsung s90c, HDR is 1022nits, SDR is 487nits: https://www.rtings.com/tv/reviews/samsung/s90c-oled#test_608 https://www.rtings.com/tv/reviews/samsung/s90c-oled#test_4

Double the range is undeniably still better.

And also 10bit instead of 8bit, so less posterization as well.

Just because the implementations have been subpar until now doesn't mean it's worthless tech to pursue.

Re: What is HDR, anyway?

#278

Post by samplatt »

munificent wrote: post #213
dahart wrote: post #185

Earlier quoted context omitted.

HDR is not referring to the scene’s range, and it doesn’t apply to film. It’s referring superficially but specifically to a digital process that improves on 8 bits/channel RGB images. And one of the original intents behind HDR was to capture pixels in absolute physical measurements like radiance, to enable a variety of post-processing workflows that are not available to film.

"High dynamic range" is a phrase that is much older than tone mapping. I see uses of "dynamic range" going back to the 1920s and "high dynamic range" to the 1940s: https://books.google.com/ngrams/graph?content=dynamic+range%... You might argue that "HDR" the abbreviation refers to using tone mapping to approximate rendering high dynamic range imagery on lower dynamic range displays. But even then, the sentence in que…

To further complicate the issue, "high dynamic range" is a phrase that will come up across a few different disciplines, not just related to the capture & reproduction of visual data.

Re: What is HDR, anyway?

#279

Post by brokenmachine »

pfranz wrote: post #264
brokenmachine wrote: post #260

Earlier quoted context omitted.

I'm with you on depth of field, but I don't understand why you think HDR reduces the fidelity of a game. If you have a good display (eg an OLED) then the brights are brighter and simultaneously there is more detail in the blacks. Why do you think that is worse than SDR?

Check out this old post: https://www.realtimerendering.com/blog/thought-for-the-day/ HDR in games would frequently mean clipping highlights and adding bloom. Prior the "HDR" exposure looked rather flat.

OK, so it doesn't mean real HDR but simulated HDR.

Maybe when proper HDR support becomes mainstream in 3D engines, that problem will go away.

Re: What is HDR, anyway?

#280

Post by pornel »

esperent wrote: post #261
pornel wrote: post #256

Earlier quoted context omitted.

Most "HDR" monitors are junk that can't display HDR. The HDR formats/signals are designed for brightness levels and viewing conditions that nobody uses. The end result is a complete chaos. Every piece of the pipeline doing something wrong, and then the software tries to compensate for it by emitting doubly wrong data, without even having reliable information about what it needs to compensate for. https://docs.google.…

What we really need is some standards that everybody follows. The reason normal displays work so well is that everyone settled on sRGB, and as long as a display gets close to that, say 95% sRGB, everyone except maybe a few graphics designers will have a n equivalent experience. But HDR, it's a minefield of different display qualities, color spaces, standards. It's no wonder that nobody gets it right and everyone feel…

DisplayHDR standard is supposed to be it, but they've ruined its reputation by allowing HDR400 to exist when HDR1000 should have been the minimum.

Besides, HDR quality is more complex than just max nits, because it depends on viewing conditions and black levels (and everyone cheats with their contrast metrics).

OLEDs can peak at 600 nits and look awesome — in a pitch black room. LCD monitors could boost to 2000 nits and display white on grey.

We have sRGB kinda working for color primaries and gamma, but it's not the real sRGB at 80 nits. It ended up being relative instead of absolute.

A lot of the mess is caused by the need to adapt content mastered for pitch black cinema at 2000 nits to 800-1000 nits in daylight, which needs very careful processing to preserve highlights and saturation, but software can't rely on the display doing it properly, and doing it in software sends false signal and risks display correcting it twice.

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