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What is HDR, anyway?

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Re: What is HDR, anyway?

#111

Post by babypuncher »

sandofsky wrote: post #64
puzzlingcaptcha wrote: post #57

Earlier quoted context omitted.

But it's not the colloquial meaning, HDR is fairly well defined by e.g. ITU-R BT.2100, which addresses colorimetry, luminance and the corresponding transfer functions.

I don't think that's the colloquial meaning. If you asked 100 people on the street to describe HDR, I doubt a single person would bring up ITU-R BT.2100.

HDR has a number of different common meanings, which adds to the confusion.

For example, in video games, "HDR" has been around since the mid '00s, and refers to games that render a wider dynamic range than displays were capable of, and use post-process effects to simulate artifcats like bloom and pupil dilation.

In photography, HDR has almost the opposite meaning of what it does everywhere else. Long and multiple exposures are combined to create an image that has very little contrast, bringing out detail in a shot that would normally be lost in shadows or to overexposure.

Re: What is HDR, anyway?

#112

Post by zamadatix »

dmos62 wrote: post #82
gyomu wrote: post #5

As a photographer, I get the appeal of (this new incarnation of) HDR content, but the practical reality is that the photos I see posted in my feeds go from making my display looking normal to having photos searing my retinas, while other content that was uniform white a second prior now looks dull gray. It's late night here so I was reading this article in dark mode, at a low display brightness - and when I got to th…

That's not inherent to HDR though. BFV (unless I'm confusing it with something else) has a HDR adjustment routine where you push a slider until the HDR white and the SDR white are identical. Same could be done for desktop environments. In my experience, HDR support is very lacking in PCs atm. You can't even play Dolby Vision on Windows, which is the only widely-used HDR format with dynamic metadata.

If you mean https://i.imgur.com/0LtYuDZ.jpeg that is probably the slider GP wants but it's not about matching HDR white to SDR white, it's just about clamping the peak HDR brightness in its own consideration. The white on the left is the HDR brightness according to a certain value in nits set via the bottom slider. The white on the right is the maximally bright HDR signal. The goal of adjusting the slider is to find how bright of an HDR white your display can actually produce, which is the lowest slider value at which the two whites appear identical to a viewer.

Some games also have a separate slider https://i.imgur.com/wenBfZY.png for adjusting "paper white", which is the HDR white one might normally associate with matching to SDR reference white (100 nits when in a dark room according to the SDR TV color standards, higher in other situations or standards). Extra note: the peak brightness slider in this game (Red Dead Redemption 2) is the same knob as the brightness slider in the above Battlefield V screenshot)

Re: What is HDR, anyway?

#113

Post by 98codes »

colechristensen wrote: post #76
reaperducer wrote: post #70

Earlier quoted context omitted.

This is also true for consumers. I don't own a single 4k or HDR display. I probably won't own an HDR display until my TV dies, and I probably won't own a 4k display until I replace my work screen, at which point I'll also replace one of my home screens so I can remote into it without scaling. People in the HN echo chamber over-estimate hardware adoption rates. For example, there are millions of people who went straig…

>there are millions of people who went straight from CDs to streaming, without hitting the iPod era Who? There was about a decade there where everyone who had the slightest interest in music had an mp3 player of some kind, at least in the 15-30 age bracket.

My father, for one. He was entirely happy with radio in the car and CDs at home.

Re: What is HDR, anyway?

#114

Post by altairprime »

skhameneh wrote: post #29
gyomu wrote: post #5

As a photographer, I get the appeal of (this new incarnation of) HDR content, but the practical reality is that the photos I see posted in my feeds go from making my display looking normal to having photos searing my retinas, while other content that was uniform white a second prior now looks dull gray. It's late night here so I was reading this article in dark mode, at a low display brightness - and when I got to th…

I’m under the impression this is caused by the use of “HDR mode”(s) and poor adaptive brightness implementations on devices. Displays such as the iPad Pro w/ OLED are phenomenal and don’t seem to implement an overactive adaptive brightness. HDR content has more depth without causing brightness distortion. In contrast, my TV will change brightness modes to display HDR content and disables some of the brightness adjust…

Apple’s method involves a good deal of what they call “EDR”, wherein the display gamma is ramped down in concert with ramping the brightness up, so that the brighter areas get brighter while the non-bright areas remain dark due to gamma math; that term is helpful for searching their WWDC developer videos for more details.

Re: What is HDR, anyway?

#115

Post by adgjlsfhk1 »

NelsonMinar wrote: post #94

Is there a consensus definition of what counts as "HDR" in a display? What is the "standard dynamic range" of a typical TV or computer monitor? Is it roughly the same for devices of the same age? My understanding is most SDR TVs and computer screens have displays about 200-300 nits (aka cd/m²). Is that the correct measure of the range of the display? The brightest white is 300 nits brighter than the darkest black?

this isn't a correct definition. human perception of brightness is roughly logarithmic, so it also matters how deep the blacks get. For a good HDR experience, you need a monitor that gets to 600 nits at a bare minimum, but also which can get very close to 0 nits (e.g. via OLED or less optionally local dimming)

Re: What is HDR, anyway?

#116

Post by simoncion »

SomeoneOnTheWeb wrote: post #13
the__alchemist wrote: post #4

So, HN, are HDR monitors worth it? I remember ~10 years ago delaying my monitor purchase for the HDR one that was right around the corner, but never (in my purchasing scope) became available. Time for another look? The utility of HDR (as described in the article) is without question. It's amazing looking at an outdoors (or indoors with windows) scene with your Mk-1 eyeballs, then taking a photo and looking at it on a…

IF you have a display that can it roughly a 1000 nits, then for movies and games yes definitely the difference with SDR is pretty huge. If you have say a 400 nits display the HDR may actually look worse than SDR. So it really depends on your screen.

Honestly, I find the extended brightness FAR less important than the extended color gamut. I have a ~300 nit VA monitor that I'm generally quite happy with and that looks fantastic with well-built HDR renderers.

Given that monitors report information about their HDR minimum and maximum panel brightness capabilities to the machine they are connected to, any competently-built HDR renderer (whether that be for games or movies or whatever) will be able to take that information and adjust the picture appropriately.

Re: What is HDR, anyway?

#117

Post by 98codes »

kllrnohj wrote: post #12
the__alchemist wrote: post #4

So, HN, are HDR monitors worth it? I remember ~10 years ago delaying my monitor purchase for the HDR one that was right around the corner, but never (in my purchasing scope) became available. Time for another look? The utility of HDR (as described in the article) is without question. It's amazing looking at an outdoors (or indoors with windows) scene with your Mk-1 eyeballs, then taking a photo and looking at it on a…

HDR gaming: Yes. HDR full screen content: Yes. HDR general desktop usage: No. In fact you'll probably actively dislike it to the point of just turning it off entirely. The ecosystem just isn't ready for this yet, although with things like the "constrained-high" concepts ( https://www.w3.org/TR/css-color-hdr-1/#the-dynamic-range-lim... ) this might, and hopefully does, change & improve to a more pleasing result Also t…

Every few years I turn on that HDR toggle for my desktop PC, and it never lasts longer than a day or two.

Top tip: If you have HDR turned on for your display in Windows (at least, MacOS not tested) and then share your screen in Teams, your display will look weirdly dimmed for everyone not using HDR on their display—which is everyone.

Re: What is HDR, anyway?

#118

Post by caseyy »

HDR is when you’re watching a dark film at night, looking at the subtle nuances between shades of dark and black in the shadows on the screen, making out the faint contours the film director carefully curated, and the subtitles gently deposit 40W of light into your optical nerves with “♪”.

Re: What is HDR, anyway?

#119

Post by altairprime »

babypuncher wrote: post #111
sandofsky wrote: post #64

Earlier quoted context omitted.

I don't think that's the colloquial meaning. If you asked 100 people on the street to describe HDR, I doubt a single person would bring up ITU-R BT.2100.

HDR has a number of different common meanings, which adds to the confusion. For example, in video games, "HDR" has been around since the mid '00s, and refers to games that render a wider dynamic range than displays were capable of, and use post-process effects to simulate artifcats like bloom and pupil dilation. In photography, HDR has almost the opposite meaning of what it does everywhere else. Long and multiple exp…

Photography’s meaning is also about a hundred years older than video games; high(er) dynamic range was a concern in film processing as far back as Ansel, if not prior. That technology adopted it as a sales keyword is interesting and it’s worth keeping in mind when writing for an audience — but this post is about a photography app, not television content or video games, so one can reasonably expect photography’s definition to be used, even if the audience isn’t necessarily familiar.

Re: What is HDR, anyway?

#120

Post by spoonsort »

sandofsky wrote: post #21
gyomu wrote: post #5

As a photographer, I get the appeal of (this new incarnation of) HDR content, but the practical reality is that the photos I see posted in my feeds go from making my display looking normal to having photos searing my retinas, while other content that was uniform white a second prior now looks dull gray. It's late night here so I was reading this article in dark mode, at a low display brightness - and when I got to th…

While it isn't touched on in the post, I think the issue with feeds is that platforms like Instagram have no interest in moderating HDR. For context: YouTube automatically edits the volume of videos that have an average loudness beyond a certain threshold. I think the solution for HDR is similar penalization based on log luminance or some other reasonable metric. I don't see this happening on Instagram any time soon,…

Why is nobody talking about the standards development? They (OS, image formats) could just say all stuff by default assumes SDR and if a media file explicitly calls for HDR even then it cannot have sharp transitions except in special cases, and the software just blocks or truncates any non conforming images. The OS should have had something like this for sound, about 25-30 years ago. For example a brightness aware OS/monitor combo could just outright disallow anything about x nits. And disallow certain contrast levels, in the majority of content.
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