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 lose color resolution in super dark color. As a photographer, with HDR you can re-expose the image when you display/print it, where previously that wasn’t possible. Previously when you took a photo, if you over-exposed it or under-exposed it, you were stuck with what you got. Capturing HDR gives the photographer one degree of extra freedom, allowing them to adjust exposure after the fact. Ansel Adams wasn’t using HDR in the same sense we’re talking about, he was just really good at capturing the right exposure for his medium without needing to adjust it later. There is a very valid argument to be made for doing the work up-front to capture what you’re after, but ignoring that for a moment, it is simply not possible to re-expose Adams’ negatives to reveal color detail he didn’t capture. That’s why he’s not using HDR, and why saying he is will only further muddy the water.
miladyincontrol · 3m ago
I do prefer the gain map approach myself. Do a sensible '32 bit' HDR edit, further tweak an SDR version, and export a file that has both.
Creative power is still in your hands versus some tone mapper's guesses at your intent.
Can people go overboard? Sure, but thats something they will do regardless of any hdr or lack thereof.
On an aside its still rough that just about every site that touches gain map (adaptive HDR as this blog calls them) HDR images will lose that metadata if they need to scale, recompress, or transform the images otherwise. Its led me to just make my own site, but also to handle what files a client gets a bit smarter . For instance if a browser doesnt support .jxl or .avif images, im sure it wont want an hdr jpeg either, thats easy to handle on a webserver.
gyomu · 3h ago
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 the HDR photos I had to turn down my display even more to not strain my eyes, then back up again when I scrolled to the text.
For fullscreen content (games, movies) HDR is alright, but for everyday computing it's a pretty jarring experience as a user.
sandofsky · 3h ago
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, because bad HDR likely makes view counts go up.
As for the HDR photos in the post, well, those are a bit strong to show what HDR can do. That's why the Mark III beta includes a much tamer HDR grade.
altairprime · 18m ago
Instagram has to allow HDR for the same reason that Firefox spent the past twenty years displaying web colors like HN orange at maximum display gamut rather than at sRGB calibrated: because a brighter red than anyone else’s draws people in, and makes the competition seem lifeless by comparison, especially in a mixed-profiles environment. Eventually that is regarded as ‘garishly bright’, so to speak, and people push back against it. I assume Firefox is already fixing this to support the latest CSS color spec (which defines #rrggbb as sRGB and requires it to be presented as such unless stated otherwise in CSS), but I doubt Instagram is willing to literally dim their feed; instead, I would expect them to begin AI-HDR’ing SDR uploads in order that all videos are captivatingly, garishly, bright.
tart-lemonade · 53m ago
> YouTube automatically edits the volume of videos that have an average loudness beyond a certain threshold.
For anyone else who was confused by this, it seems to be a client-side audio compressor feature (not a server-side adjustment) labeled as "Stable Volume". On the web, it's toggleable via the player settings menu.
I didn't realize this was a thing until just now, but I'm glad they added it because (now that I think about it) it's been awhile since I felt the need to adjust my system volume when a video was too quiet even at 100% player volume. It's a nice little enhancement.
scraptor · 43m ago
The client side toggle might be new since 2024 but the volume normalisation has been a thing for a long time.
spoonsort · 24m ago
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.
SquareWheel · 1h ago
FYI: You wrote Chrome 14 in the post, but I believe you meant Android 14.
sandofsky · 1h ago
Thanks. Updated.
corndoge · 2h ago
The effect of HDR increasing views is explicitly mentioned in the article
nightpool · 1h ago
You are replying to the article's author.
dheera · 1h ago
> because bad HDR likely makes view counts go up
Another related parallel trend recently is that bad AI images get very high view and like counts, so much so that I've lost a lot of motivation for doing real photography because the platforms cease to show them to anyone, even my own followers.
beachwood23 · 3h ago
Completely agree. To me, HDR feels like the system is ignoring my screen brightness settings.
I set my screen brightness to a certain level for a reason. Please don’t just arbitrarily turn up the brightness!
There is no good way to disable HDR on photos for iPhone, either. Sure, you can turn off the HDR on photos on your iphone. But then, when you cast to a different display, the TV tries to display the photos in HDR, and it won’t look half as good.
repelsteeltje · 2h ago
> To me, HDR feels like the system is ignoring my screen brightness settings.
You might be on to something there. Technically, HDR is mostly about profile signaling and therefore about interop. To support it in mpeg dash or hls media you need to make sure certain codec attributes are mentioned in the xml or m3u8 but the actual media payload stays the same.
Any bit or Bob being misconfigured or misinterpreted in the streaming pipeline will result in problems ranging from slightly suboptimal experience to nothing works.
Besides HDR, "spatial audio" formats like Dolby Atmos are notorious for interop isuues
kllrnohj · 2h ago
> To me, HDR feels like the system is ignoring my screen brightness settings.
On both Android & iOS/MacOS it's not that HDR is ignoring your screen brightness, but rather the brightness slider is controlling the SDR range and then yes HDR can exceed that, that's the singular purpose of HDR to be honest. All the other purported benefits of HDR are at best just about HDR video profiles and at worst just nonsense bullshit. The only thing HDR actually does is allow for brighter colors vs. SDR. When used selectively this really enhances a scene. But restraint is hard, and most forms of HDR content production are shit. The HDR images that newer iPhones and Pixel phones are capturing are generally quite good because they are actually restrained, but then ironically both of them have horrible HDR video that's just obnoxiously bright.
agos · 49m ago
you are right but at least in my experience it's very easy for a modern iPhone to capture a bad HDR photo, usually because there is some small strong highlight (often a form of specular reflection from a metallic object) that causes everything to be HDR while the photo content wouldn't need it
altairprime · 14m ago
In beta testing this morning, the Halide “HDR slider” works as intended to solve that. Some of my photos have only needed +0.3 while a couple taken in near-total no-light-pollution darkness have it cranked all the way to max and that still isn’t enough.
dmos62 · 1h ago
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.
zamadatix · 33m ago
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)
Suppafly · 1h ago
>HDR support is very lacking in PCs atm.
I think it's because no one wants it.
altairprime · 8m ago
[delayed]
skhameneh · 2h ago
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 adjustments when displaying HDR content. It can be very uncomfortably bright in a dark room while being excessively dim in a bright room. It requires adjusting settings to a middle ground resulting in a mixed/mediocre experience overall. My wife’s laptop is the worst of all our devices, while reviews seem to praise the display, it has an overreactive adaptive brightness that cannot be disabled (along with decent G2G response but awful B2W/W2B response that causes ghosting).
altairprime · 30m ago
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.
This happens on Snapchat too with HDR videos. Brightness increases while everything else dims... including the buttons.
mxfh · 3h ago
Does anyone else find the hubris in the first paragraph writing as off-putting as I do?
"we finally explain what HDR actually means"
Then spends 2/3rds of the article on a tone mapping expedition, only to not address the elephant in the room, that is the almost complete absence of predictable color management in consumer-grade digital environments.
UIs are hardly ever tested in HDR: I don't want my subtitles to burn out my eyes in actual HDR display.
It is here, where you, the consumer, are as vulnerable to light in a proper dark environment for movie watching, as when raising the window curtains on a bright summer morning.
(That brightness abuse by content is actually discussed here)
Dolby Vision and Apple have the lead here as a closed platforms, on the web it's simply not predictably possible yet.
Best hope is the efforts of the Color on the Web Community Group from my impression.
> Does anyone else find the hubris in the first paragraph writing as off-putting as I do?
> "we finally explain what HDR actually means"
No. Because it's written for the many casual photographers we've spoken with who are confused and asked for an explainer.
> Then spends 2/3rds of the article on a tone mapping expedition, only to not address the elephant in the room, that is the almost complete absence of predictable color management in consumer-grade digital environments.
That's because this post is about HDR and not color management, which is different topic.
klausa · 1h ago
>No. Because it's written for the many casual photographers we've spoken with who are confused and asked for an explainer.
To be fair, it would be pretty weird if you found your own post off-putting :P
mullingitover · 38m ago
Me, routinely, reading things I wrote a while ago: what is this dreck
mxfh · 5m ago
Maybe my response was part of the broader HDR symptom—that the acronym is overloaded with different meanings depending on where you're coming from.
On the HN frontpage, people are likely thinking of one of at least three things:
HDR as display tech (hardware)
HDR as wide gamut data format (content)
HDR as tone mapping (processing)
...
So when the first paragraph says we finally explain what HDR actually means, it set me off on the wrong foot—it comes across pretty strongly for a term that’s notoriously context-dependent. Especially in a blog post that reads like a general explainer rather than a direct Q&A response when not coming through your apps channels.
Then followed up by The first HDR is the "HDR mode" introduced to the iPhone camera in 2010. caused me to write the comment.
For people over 35 with even the faintest interest in photography, the first exposure to the HDR acronym probably didn’t arrive with the iPhone in 2010, but HDR IS equivalent to Photomatix style tone mapping starting in 2005 as even mentioned later. The ambiguity of the term is a given now. I think it's futile to insist one meaning in non-scientific informal communication.
So the age correlation of what HDR means to you users might be some interesting thing to explore.
It get's a lot better after that. That said, I really did enjoy the depth. The dive into the classic dodge and burn and the linked YouTube piece. One explainer at a time makes sense—and tone mapping is a good place to start. Even tone mapping is fine in moderation :)
altairprime · 46m ago
It seems fine to me. Made sense on the first read and matches my experiences with OpenEXR and ProPhoto RGB and pre-Apple monitors.
High dynamic resolution has always been about tone mapping. Post-sRGB color profile support is called “Wide color” these days, has been available for twenty years or more on all DSLR cameras (such as Nikon ProPhoto RGB supported in-camera on my old D70), and has nothing to do with the dynamic range and tone mapping of the photo. It’s convenient that we don’t have to use EXR files anymore, though!
An HDR photo in sRGB will have the same defects beyond peak saturation at any given hue point, as an SDR photo in sRGB would, relative to either in DCI-P3 or ProPhoto. Even a two-bit black-or-white “what’s color? on or off pixels only” HyperCard dithered image file can still be HDR or SDR. In OKLCH, the selected luminosity will also impact the available chroma range; at some point you start spending your new post-sRGB peak chroma on luminosity instead; but the exact characteristic of that tradeoff at any given hue point is defined by the color profile algorithm, not by whether the photo is SDR or HDR, and the highest peak saturation possible for each hue is fixed, whatever luminosity it happens to be at.
Diti · 2h ago
They also make no mention of transfer functions, which is the main mechanism which explains why the images “burn your eyes” – content creators should use HLG (which has relative luminance) and not PQ (which has absolute luminance) when they create HDR content for the web.
willquack · 1h ago
> That brightness abuse by content
I predict HDR content on the web will eventually be disabled or mitigated on popular browsers similarly to how auto-playing audio content is no longer allowed [1]
Spammers and advertisers haven't caught on yet to how abusively attention grabbing eye-searingly bright HDR content can be, but any day now they will and it'll be everywhere.
This seems like a fairly easy problem to solve from a UX standpoint, even moreso than auto-playing audio/video. Present all pages in SDR by default, let the user click a button on the toolbar or url bar to toggle HDR rendering when HDR content is detected.
klausa · 2h ago
It's a blog for a (fancy) iPhone camera app.
Color management and handling HDR in UIs is probably a bit out of scope.
srameshc · 1h ago
I on the other hand never thought or cared about HDR much before but I remember seeing it everywhere. But I feel the article explains well and clearly with examples, for someone like me who isn't much camera literate.
lordleft · 2h ago
Isn't that the point of the article? That the colloquial meaning of HDR is quite overloaded, and when people complain about HDR, they mean bad tone-mapping? I say this as someone as close to totally ignorant about photography as you can get; I personally thought the article was pretty spectacular.
mort96 · 2h ago
When I complain about HDR it's because I've intentionally set the brightness of pure white to a comfortable level, and then suddenly parts of my screen are brighter than that. You fundamentally can't solve that problem with just better tone mapping, can you?
Retr0id · 2h ago
You can for some definition of "solve", by tone-mapping all HDR content back down into an SDR range for display.
mort96 · 2h ago
Well yeah. I considered adding that caveat but elected not to because it's obvious and doesn't add anything to the conversation, since that's obviously not what's meant when the industry talks about "HDR". Should've remembered this is HN.
puzzlingcaptcha · 2h ago
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.
sandofsky · 2h ago
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.
babypuncher · 35m ago
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.
altairprime · 26m ago
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.
roywiggins · 1h ago
I think you may be operating with an idiosyncratic definition of "colloquial"
redczar · 58m ago
Colloquial meaning and the well defined meaning are two different things in most cases, right?
PaulHoule · 2h ago
The bit about "confused" turns me off right away. The kind of high-pressure stereo salesman who hopes I am the kind of 'audiophile' who prevents me from calling myself an 'audiophile' (wants mercury-filled cables for a more 'fluid' sound) always presupposes the reader/listener is "confused".
echo_time · 3h ago
Note for Firefox users - view the page in Chrome to see more of what they are talking about. I was very confused by some of the images, and it was a world of difference when I tried again in Chrome. Things began to make a lot more sense - is there a flag I am missing in Firefox on the Mac?
Can confirm on Windows 11 with HDR enabled on my display— I see the photos in the article correctly on Chrome and they're a grey mess on Firefox.
lloeki · 45m ago
On macOS even without HDR enabled on my display there's a striking difference due to better tone mapping between Safari and Firefox.
If I enable HDR the Firefox ones become a gray mess vs the lights feeling like actual lights in Safari.
gwbas1c · 1h ago
I wasn't using Firefox, but I had the page open on an old monitor. I dragged the page to an HDR display and the images pop.
cubefox · 2h ago
HDR support in Chrome (Android) looks still broken for me. For one, some of the images on the blog have a posterization effect, which is clearly wrong.
Second, the HDR effect seems to be implemented in a very crude way, which causes the whole Android UI (including the Android status bar at the top) to become brighter when HDR content is on screen. That's clearly not right. Though, of course, this might also be some issue of Android rather than Chrome, or perhaps of the Qualcomm graphics driver for my Adreno GPU, etc.
throwaway314155 · 2h ago
For what it's worth, your comment has me convinced I just "can't see" HDR properly because I have the same page side-by-side on Firefox and Chrome on my M4 MBP and honestly? Can't see the difference.
edit: Ah, nevermind. It seems Firefox is doing some sort of post-processing (maybe bad tonemapping?) on-the-fly as the pictures start out similar but degrade to washed out after some time. In particular, the "OVERTHROW BOXING CLUB" photo makes this quite apparent.
That's a damn shame Firefox. C'mon, HDR support feels like table stakes at this point.
edit2: Apparently it's not table stakes.
> Browser support is halfway there. Google beat Apple to the punch with their own version of Adaptive HDR they call Ultra HDR, which Chrome 14 now supports. Safari has added HDR support into its developer preview, then it disabled it, due to bugs within iOS.
at which point I would just say to `lux.camera` authors - why not put a big fat warning at the top for users with a Firefox or Safari (stable) browser? With all the emphasis on supposedly simplifying a difficult standard, the article has fallen for one of its most famous pitfalls.
"It's not you. HDR confuses tons of people."
Yep, and you've made it even worse for a huge chunk of people. :shrug: Great article n' all just saying.
gwbas1c · 1h ago
> AI cannot read your mind, so it cannot honor your intent.
This. I can always tell when someone "gets" software development when they either understand (or don't) that computers can't read minds or infer intent like a person can.
asafira · 1h ago
I did my PhD in Atomic, Molecular, and Optical (AMO) physics, and despite "optical" being part of that I realized midway that I didn't know enough about how regular cameras worked!
It didn't take very long to learn, and it turned out to be extremely important in the work I did during the early days at Waymo and later at Motional.
I wanted to pass along this fun video from several years ago that discusses HDR: https://www.youtube.com/watch?v=bkQJdaGGVM8 . It's short and fun, I recommend it to all HN readers.
Separately, if you want a more serious introduction to digital photography, I recommend the lectures by Marc Levoy from his Stanford course: https://www.youtube.com/watch?v=y7HrM-fk_Rc&list=PL8ungNrvUY... . I believe he runs his own group at Adobe now after leading a successful effort at Google making their pixel cameras the best in the industry for a couple of years. (And then everyone more-or-less caught up, just like with most tech improvements in the history of smartphones).
aidenn0 · 2h ago
> A big problem is that it costs the TV, Film, and Photography industries billions of dollars (and a bajillion hours of work) to upgrade their infrastructure. For context, it took well over a decade for HDTV to reach critical mass.
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.
gwbas1c · 1h ago
> I don't own a single 4k or HDR display
Don't feel like you have to. I bought a giant fancy TV with it, and even though it's impressive, it's kinda like ultra-hifi-audio. I don't miss it when I watch the same show on one of my older TVs.
If you ever do get it, I suggest doing for a TV that you watch with your full attention, and watching TV / movies in the dark. It's not very useful on a TV that you might turn on while doing housework; but very useful when you are actively watching TV with your full attention.
anon7000 · 15m ago
I totally love HDR on my OLED TV, and definitely miss it on others.
Like a lot of things, it’s weird how some people are more sensitive to visual changes. For example:
- At this point, I need 120hz displays. I can easily notice when my wife’s phone is in power saver mode at 60hz.
- 4k vs 1080p. This is certainly more subtle, but I definitely miss detail in lower res content.
- High bitrate. This is way more important than 4k vs 1080p or even HDR. But it’s so easy to tell when YouTube lowers the quality setting on me, or when a TV show is streaming at a crappy bitrate.
- HDR is tricky, because it relies completely on the content creator to do a good job producing HDR video. When done well, the image basically sparkles, water looks actually wet, parts of the image basically glow… it looks so good.
I 100% miss this HDR watching equivalent content on other displays. The problem is that a lot of content isn’t produced to take advantage of this very well. The HDR 4k Blu-ray of several Harry Potter movies, for example, has extremely muted colors and dark scenes… so how is the image going to pop? I’m glad we’re seeing more movies rely on bright colors and rich, contrasty color grading. There are so many old film restorations that look excellent in HDR because the original color grade had rich, detailed, contrasty colors.
On top of that, budget HDR implementations, ESPECIALLY in PC monitors, just don’t get very bright. Which means their HDR is basically useless. It’s impossible to replicate the “shiny, wet look” of really good HDR water if the screen can’t get bright enough to make it look shiny. Plus, it needs to be selective about what gets bright, and cheap TVs don’t have a lot of backlighting zones to make that happen very well.
So whereas I can plug in a 4k 120hz monitor and immediately see the benefit in everything I do for normal PC stuff, you can’t get that with HDR unless you have good source material and a decent display.
alerighi · 1h ago
I don't either see a point of having 4K TV vs 1080p TV. To me is just marketing, I have at my house both a 4K and a 1080p and from a normal viewing distance (that is 3/4 meters) you don't see differences.
Also in my country (Italy) TV transmissions are 1080i at best, a lot are still 570i (PAL resolution). Streaming media can be 4K (if you have enough bandwidth to stream it at that resolution, which I don't have at my house). Sure, if you download pirated movies you find it at 4K, and if you have the bandwidth to afford it... sure.
But even there, sometimes is better a well done 1080p movie than an hyper compressed 4K one, since you see compression artifacts.
To me 1080p, and maybe even 720p, is enough for TV vision. Well, sometimes I miss the CRT TVs, they where low resolution but for example had a much better picture quality than most modern 4K LCD TV where black scenes are gray (I know there is OLED, but is too expensive and has other issues).
dmitshur · 2h ago
To demonstrate some contrast (heh) with another data point from someone closer to the other extreme, I’ve owned a very HDR-capable monitor (the Apple Pro Display XDR) since 2020, so that’s 5 years now. Content that takes full advantage of it is still rare, but it’s getting better slowly over time.
colechristensen · 1h ago
I have a screen which is "HDR" but what that means is when you turn the feature on it just makes everything more muted, it doesn't actually have any more dynamic range. When you turn HDR on for a game it basically just makes most things more muddy grey.
I also have a screen which has a huge gamut and blows out colors in a really nice way (a bit like the aftereffects of hallucinogens, it has colors other screens just don't) and you don't have to touch any settings.
My OLED TV has HDR and it actually seems like HDR content makes a difference while regular content is still "correct".
babypuncher · 24m ago
Pretty much any display you can buy today will be HDR capable, though that doesn't mean much.
I think the industry is strangling itself putting "DisplayHDR 400" certification on edgelit/backlit LCD displays. In order for HDR to look "good" you either need high resolution full array local dimming backlighting (which still isn't perfect), or a panel type that doesn't use any kind of backlighting like OLED.
Viewing HDR content on these cheap LCDs often looks worse than SDR content. You still get the wider color gamut, but the contrast just isn't there. Local dimming often loses all detail in shadows whenever there is something bright on the screen.
reaperducer · 1h ago
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 straight from CDs to streaming, without hitting the iPod era.
A few years ago on HN, there was someone who couldn't wrap their brain around the notion that even though VCRs were invented in the early 1960's that in 1980, not everyone owned one, or if they did, they only had one for the whole family.
Normal people aren't magpies who trash their kit every time something shiny comes along.
babypuncher · 18m ago
> A few years ago on HN, there was someone who couldn't wrap their brain around the notion that even though VCRs were invented in the early 1960's that in 1980, not everyone owned one, or if they did, they only had one for the whole family.
Point of clarification: While the technology behind the VCR was invented in the '50s and matured in the '60s, consumer-grade video tape systems weren't really a thing until Betamax and VHS arrived in 1975 and 1976 respectively.
Early VCRs were also incredibly expensive, with prices ranging from $3,500 to almost $10,000 after adjusting for inflation. Just buying into the VHS ecosystem at the entry level was a similar investment to buying an Apple Vision Pro today.
colechristensen · 1h ago
>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.
Sohcahtoa82 · 21m ago
I imagine this depends a LOT on your specific age and what you were doing in the 00's when MP3 player usage peaked.
I finished high school in 2001 and didn't immediately go to college, so I just didn't have a need for a personal music player anymore. I was nearly always at home or at work, and I drove a car that actually had an MP3 CD player. I felt no need to get an iPod.
In 2009, I started going to college, but then also got my first smartphone, the Motorola Droid, which acted as my portable MP3 player for when I was studying in the library or taking mass transit.
If you were going to school or taking mass transit in the middle of the '00s, then you were probably more likely to have a dedicated MP3 player.
98codes · 31m ago
My father, for one. He was entirely happy with radio in the car and CDs at home.
aidenn0 · 1h ago
I don't know if I count, but I never owned a dedicated MP3 player[1], I listened to MP3s on my computer, but used CDs and cassettes while on the move, until I got an android phone that had enough storage to put my music collection on.
1: Well my car would play MP3s burned to CDs in its CD player; not sure if that counts.
caseyy · 26m ago
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 “♪”.
CarVac · 3h ago
HDR on displays is actually largely uncomfortable for me. They should reserve the brightest HDR whites for things like the sun itself and caustics, not white walls in indoor photos.
As for tone mapping, I think the examples they show tend way too much towards flat low-local-contrast for my tastes.
NBJack · 2h ago
HDR is really hard to get right apparently. It seems to get worse in video games too.
I'm a huge fan of Helldivers 2, but playing the game in HDR gives me a headache: the muzzle flash of weapons at high RPMs on a screen that goes to 240hz is basically a continuous flashbang for my eyes.
For a while, No Mans' Sky in HDR mode was basically the color saturation of every planet dialed up to 11.
The only game I've enjoyed at HDR was a port from a console, Returnal. The use of HDR brights was minimalistic and tasteful, often reserved for certain particle effects.
simoncion · 37m ago
For a year or two after it launched, The Division 2 was a really, really good example of HDR done right. The game had (has?) a day/night cycle, and it had a really good control of the brightness throughout the day. More importantly, it made very good use of the wide color gamut available to it.
I stopped playing that game for several years, and when I went back to it, the color and brightness had been wrecked to all hell. I have heard that it's received wisdom that gamers complain that HDR modes are "too dark", so perhaps that's part of why they ruined their game's renderer.
Some games that I think currently have good HDR:
* Lies of P
* Hunt: Showdown 1896
* Monster Hunter: World (if you increase the game's color saturation a bit from its default settings)
Some games that had decent-to-good HDR the last time I played them, a few years ago:
* Battlefield 1
* Battlefield V
* Battlefield 2042 (If you're looking for a fun game, I do NOT recommend this one. Also, the previous two are probably chock-full of cheaters these days.)
I found Helldivers 2's HDR mode to have blacks that were WAY too bright. In SDR mode, nighttime in forest areas was dark. In HDR mode? It was as if you were standing in the middle of a field during a full moon.
the_af · 1h ago
There's a pretty good video on YouTube (more than one, actually) that explains how careless use of HDR in modern cinema is destroying the look and feel of cinema we used to like.
Everything is flattened, contrast is eliminated, lights that should be "burned white" for a cinematic feel are brought back to "reasonable" brightness with HDR, really deep blacks are turned into flat greys, etc. The end result is the flat and washed out look of movies like Wicked. It's often correlated to CGI-heavy movies, but in reality it's starting to affect every movie.
sergioisidoro · 3h ago
Just one other thing. In Analog you also have compensating developers, which will exhaust faster in darker areas (or lighter if you think in negative), and allow for lighter areas more time to develop and show, and hence some more control of the range. Same but to less degree with stand development which uses very low dilutions of the developer, and no agitation. So dodging and burning is not the only way to achieve higher dynamic range in analog photos.
About HDR on phones, I think they are the blight of photography. No more shadows and highlights. I find they are good at capturing family moments, but not as a creative tool.
CarVac · 2h ago
I wrote a raw processing app Filmulator that simulates stand development/compensating developers to give such an effect to digital photography.
I still use it myself but I need to redo the build system and release it with an updated LibRaw... not looking forward to that.
the__alchemist · 3h ago
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 phone or PC screen. The pic fails to capture what your eyes see for lighting range.
kllrnohj · 3h ago
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 this is assuming an HDR monitor that's also a good match for your ambient environment. The big thing nobody really talks about wiith HDR is that it's really dominated by how dark you're able to get your surrounding environment such that you can push your display "brightness" (read: SDR whitepoint) lower and lower. OLED HDR monitors, for example, look fantastic in SDR and fantastic in HDR in a dark room, but if you have typical office lighting and so you want an SDR whitepoint of around 200-300 nits? Yeah, they basically don't do HDR at all anymore at that point.
Sohcahtoa82 · 11m ago
> HDR gaming: Yes.
The difference is absolutely stunning in some games.
In MS Flight Simulator 2024, going from SDR to HDR goes from looking like the computer game it is to looking life-like. Deeper shadows with brighter highlights makes the scene pop in ways that SDR just can't do.
EDIT: You'll almost certainly need an OLED monitor to really appreciate it, though. Local dimming isn't good enough.
98codes · 27m ago
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.
wirybeige · 1h ago
I use HDR for general usage, Windows ruins non-HDR content when HDR is enabled due to their choice of sRGB tf. Luckily every Linux DE has chosen to use the gamma 2.2 tf, and looks fine for general usage.
I use a mini-led monitor, and its quite decent, except for starfields, & makes it very usable even in bright conditions, and HDR video still is better in bright conditions than the equivalent SDR video.
HDR on desktop in windows looks straight up broken on some HDR monitors I’ve tried
Like totally washed out
eschatology · 3h ago
Yes but with asterisks; Best way I can describe it:
You know the 0-10 brightness slider you have to pick at the start of a game? Imagine setting it to 0 and still being able to spot the faint dark spot. The dynamic range of things you can see is so much expanded.
Early HDR screens were very limited (limited dimming zones, buggy implementation) but if you get one post 2024 (esp the oled ones) they are quite decent.
However it needs to be supported at many layers: not just the monitor, but also the operating system, and the content. There are not many games with proper HDR implementation; and even if there is, it may be bad and look worse — the OS can hijack the rendering pipeline and provide HDR map for you (Nvidia RTX HDR) which is a gamble: it may look bleh, but sometimes also better than the native HDR implementation the game has).
But when everything works properly, wow it looks amazing.
kllrnohj · 2h ago
> You know the 0-10 brightness slider you have to pick at the start of a game? Imagine setting it to 0 and still being able to spot the faint dark spot. The dynamic range of things you can see is so much expanded.
Note that HDR only actually changes how bright things can get. There's zero difference in the dark regions. This is made confusing because HDR video marketing often claims it does, but it doesn't actually. HDR monitors do not, in general, have any advantage over SDR monitors in terms of the darks. Local dimming zones improve dark contrast. OLED improves dark contrast. Dynamic contrast improves dark contrast. But HDR doesn't.
eschatology · 2h ago
My understanding is that on the darker scenes (say, 0 to 5 in the brightness slider example), there is difference in luminance value with HDR but not SDR, so there is increased contrast and detail.
This matches my experience; 0 to 5 look identically black if I turn off HDR
kllrnohj · 1h ago
You may have a monitor that only enables local dimming zones when fed an HDR signal but not when fed an SDR one, but that would be unusual and certainly not required. And likely something you could change in your monitors controls. On things like an OLED, though, there's no difference in the darks. You'd see a difference between 8bit and 10bit potentially depending on what "0 to 5" means, but 10-bit SDR is absolutely a thing (it predates HDR even)
But like if you can't see a difference between 0 to 5 in a test pattern like this https://images.app.goo.gl/WY3FhCB1okaRANc28 in SDR but you can in HDR then that just means your SDR factory calibration is bad, or you've fiddled with settings that broke it.
nfriedly · 2h ago
A lot of monitors that advertise HDR support really shouldn't. Many of them can decode the signal but don't have the hardware to accurately reproduce it, so you just end up with a washed out muddy looking mess where you're better off disabling HDR entirely.
As others here have said, OLED monitors are generally excellent at reproducing a HDR signal, especially in a darker space. But they're terrible for productivity work because they'll get burned in for images that don't change a lot. They're fantastic for movies and gaming, though.
There are a few good non-OLED HDR monitors, but not many. I have an AOC Q27G3XMN; its a 27" 1440p 180hz monitor that is good for entry-level HDR, especially in brighter rooms. It has over 1000 nits of brightness, and no major flaws. It only has 336 backlight zones, though, so you might notice some blooming around subtitles or other fine details where there's dark and light content close together. (VA panels are better than IPS at suppressing that, though.) It's also around half the price of a comparable OLED.
Most of the other non-OLED monitors with good HDR support have some other deal-breaking flaws or at least major annoyances, like latency, screwing up SDR content, buggy controls, etc. The Monitors Unboxed channel on YouTube and rtngs.com are both good places to check.
Sohcahtoa82 · 5m ago
I think an OLED is basically an absolute necessity for HDR content.
My current monitor is an OLED and HDR in games looks absolutely amazing. My previous was an IPS that supported HDR, but turning it on caused the backlight to crank to the max, destroying black levels and basically defeating the entire purpose of HDR. Local dimming only goes so far.
Jhsto · 3h ago
I've been thinking of moving out of the Apple ecosystem but after seeing Severance on my iPhone Pro screen I feel like I want the keep the option to have the same HDR experience for movies specifically. With HDR support landing in Linux just a month ago I'm inclined to spend on a good monitor. However, I have IPS HDR 600 monitor but I never felt that the screen was as glorious as the iPhone screen.
I'd also be interested in hearing whether it makes sense to look into OLED HDR 400 screens (Samsung, LG) or is it really necessary to get an Asus ProArt which can push the same 1000 nits average as the Apple XDR display (which, mind you, is IPS).
SomeoneOnTheWeb · 3h ago
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.
simoncion · 29m ago
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.
esperent · 3h ago
I think it depends on the screen and also what you use it for. My OLED is unusable for normal work in HDR because it's designed around only a small portion of the screen being at max brightness - reasonable for a game or movie, but the result is that a small window with white background will look really bright, but if I maximize it, it'll look washed out, grey not white.
Also the maximum brightness isn't even that bright at 800 nits, so no HDR content really looks that different. I think newer OLEDs are brighter though. I'm still happy with the screen in general, even in SDR the OLED really shines. But it made me aware not all HDR screens are equal.
Also, in my very short experiment using HDR for daily work I ran into several problems, the most serious of which was the discovery that you can no longer just screenshot something and expect it to look the same on someone else's computer.
simoncion · 19m ago
> ...the most serious of which was the discovery that you can no longer just screenshot something and expect it to look the same on someone else's computer.
To be pedantic, this has always been the case... Who the hell knows what bonkers "color enhancement" your recipient has going on on their end?
But (more seriously) it's very, very stupid that most systems out there will ignore color profile data embedded in pictures (and many video players ignore the same in videos [0]). It's quite possible to tone-map HDR stuff so it looks reasonable on SDR displays, but color management is like accessibility in that nearly noone who's in charge of paying for software development appears to give any shits about it.
[0] A notable exception to this is MPV. I can't recommend this video player highly enough.
SebastianKra · 2h ago
Apple's Displays yes. But I got a Phillips 4k OLED recently, and I'm already regretting that decision. I need to turn it off every 4 hours to refresh the pixels. Sometimes an entire line of pixels is brighter than the rest. I wiped it with a cloth while pixel refresh was running, and then saw burned in streaks in the direction of the wipe.
And thats now that all the LEDs are still fresh. I can't imagine how bad it will be in a few years.
Also, a lot of Software doesn't expect the subpixel arrangement, so text will often look terrible.
baq · 1h ago
I've had an OLED TV since 2017 and the answer is a resounding yes... if you get an OLED and use it for movies or full screen gaming. Anything else is basically pointless.
For desktop work, don't bother unless your work involves HDR content.
aethrum · 3h ago
For gaming, definitely. An HDR Oled monitor is so immersive.
whywhywhywhy · 2h ago
Dunno if it's just my screen or setup but on windows I have a Dell U4025QW and HDR on the desktop just looks strange, overly dull. Looks good in games but I have to manually turn it on and off each time on the screen.
On my Macbook Pro only activates when it needs to but honestly I've only seen one video [1] that impressed me with it, the rest was completely meh. Not sure if its because it's mostly iPhone photography you see in HDR which is overall pretty meh looking anyway.
[1] https://www.youtube.com/watch?v=UwCFY6pmaYY I understand this isn't a true HDR process but someone messing with it in post, but it's the only video I've seen that noticeably shows you colors you can't see on a screen otherwise.
NelsonMinar · 1h ago
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)
tomatotomato37 · 2h ago
If anyone was hoping for a more technical explanation, I find these pages do a good job explaining the inner workings behind the format
I'm not entirely convinced that greedy influencers are to blame for people hating on overly bright content. Instead, I think something is different with how displays produce brightness compared to just the nature outside. Light outside is supposed to reach up to tens of thousands of nits, yet even 1000 nits is searing on a display. Is it that displays output polarized light? Is it the spectral distribution of especially the better displays being three really tight peaks? I cannot tell you, but I'm suspecting something isn't quite right.
All this aside, HDR and high brightness are different things - HDR is just a representational thing. You can go full send on your SDR monitor as well, you'll just see more banding. The majority of the article is just content marketing about how they perform automatic tonemapping anyways.
ziml77 · 2h ago
It's all down to the ambient light. That's why bias lighting is now a thing. Try putting a light behind your screen to massively brighten the wall behind it, the 1000 nit peaks will be far less harsh. And if you bring the device out into sunlight I suspect you will wish for everything about its output to be quite a bit brighter.
layer8 · 1h ago
> Light outside is supposed to reach up to tens of thousands of nits, yet even 1000 nits is searing on a display.
That’s a consequence of https://en.wikipedia.org/wiki/Adaptation_(eye). If you look at 1000 nits on a display in bright sunlight, with your eyes adapted to the bright surroundings, the display would look rather dim.
A lot of these design flaws are fixed by Firefox's picture in picture option but for some reason, with the way you coded it, the prompt to pop it out as PIP doesn't show up
hatsunearu · 1h ago
Is there any workflow that can output HDR photos (like the real HDR kind, with metadata to tell the display to go into HDR mode) for photos shot with a mirrorless and not an iPhone?
bookofjoe · 2h ago
As a non-techie I represent the 99.9% of the population who haven't a clue what tone mapping etc. is: NO WAY would we ever touch the various settings possible as opposed to watching the TV/computer screen/etc. as it came out of the box.
dsego · 2h ago
Isn't the result of their tone mapping algo similar to adjusting shadow and highlight sliders in other software?
sandofsky · 2h ago
No. When you simply adjust shadow and highlights, you lose local contrast. In an early draft of the post, there was an example, but it was cut for pacing.
alistairSH · 2h ago
"The Ed Hardy T-Shirt of Photography"
Literal snort.
randall · 2h ago
This was super awesome. Thanks for this! Especially the HDR photo reveal felt really awesome.
fogleman · 2h ago
So, if cameras have poor dynamic range, how are they getting away with a single exposure? They didn't explain that at all...
sandofsky · 2h ago
Human vision has around 20 stops of static dynamic range. Modern digital cameras can't match human vision— a $90,000 Arri Alexa boasts 17 stops— but they're way better than SDR screens.
cainxinth · 2h ago
I chuckled at "The Ed Hardy t-shirt of photography" for the early, overdone "HDR-mode" images.
c-fe · 2h ago
i am still skeptical about HDR as pretty much all HDR content I see online is awful. But this post makes me believe that Lux/Halide can pull of HDR in a way that I will like. I am looking forward to Halide Mk3.
esperent · 3h ago
This page crashed Brave on Android three times before I gave up.
mcjiggerlog · 1h ago
For me this crashed in android webview, android chrome, and android firefox. Impressive.
therealmarv · 2h ago
... something Linux Desktops don't understand and Macs only do well with their own displays with videos. Guess who the winner is on the desktop: Windows oO
dismalaf · 17m ago
Linux does HDR. It's *technically" worked for years but none of the big DEs had it working. Now Ubuntu 25.04 and Fedora 42 (Gnome) have it working out of the box.
4ad · 3h ago
HDR is just a scene-referred image using absolute luminance.
kllrnohj · 3h ago
No, it isn't. Absolute luminance is a "feature" of PQ specifically used by HDR10(+) and most DolbyVision content (notably the DolbyVision as produced by an iPhone is not PQ, it's not "real" DolbyVision). But this is not the only form of HDR and it's not even the common form for phone cameras. HLG is a lot more popular for cameras and it is not in absolute luminance. The gainmap-based approach that Google, Apple, and Adobe are all using is also very much not absolute luminance, either. In fact that flips it entirely and it's SDR relative instead, which is a much better approach to HDR than what video initially went with.
pavlov · 3h ago
Ideally in the abstract it could be just that, but in practice it's an umbrella name for many different techniques that provide some aspect of that goal.
the__alchemist · 3h ago
Not in the more general sense! It can refer to what its acronym spells out directly: Bigger range between dimmest and brightest capabilities of a display, imaging technique etc.
4ad · 3h ago
No. HDR can encode high dynamic range because (typically) it uses floating point encoding.
From a technical point of view, HDR is just a set of standards and formats for encoding absolute-luminance scene-referred images and video, along with a set of standards for reproduction.
dahart · 6m ago
I think most HDR formats do not typically use 32 bit floating point. The first HDR file format I can remember is Greg Ward’s RGBE format, which is also now more commonly known as .HDR and I think is pretty widely used.
It uses a type of floating point, in a way, but it’s a shared 8 bit exponent across all 3 channels, and the channels are still 8 bits each, so the whole thing fits in 32 bits. Even the .txt file description says it’s not “floating point” per-se since that implies IEEE single precision floats.
Cameras and displays don’t typically use floats, and even CG people working in HDR and using, e.g., OpenEXR, might use half floats more often that float.
Some standards do exist, and it’s improving over time, but the ideas and execution of HDR in various ways preceded any standards, so I think it’s not helpful to define HDR as a set of standards. From my perspective working in CG, HDR began as a way to break away from 8 bits per channel RGB, and it included improving both color range and color resolution, and started the discussion of using physical metrics as opposed to relative [0..1] ranges.
cornstalks · 3h ago
No. HDR video (and images) don't use floating point encoding. They generally use a higher bit depth (10 bits or more vs 8 bits) to reduce banding and different transfer characteristics (i.e. PQ or HLG vs sRGB or BT.709), in addition to different YCbCr matrices and mastering metadata.
And no, it's not necessarily absolute luminance. PQ is absolute, HLG is not.
skhameneh · 2h ago
Isn’t HLG using floating point(s)?
Also DCI-P3 should fit in here somewhere, as it seems to be the most standardized color space for HDR. I would share more insight, if I had it. I thought I understood color profiles well, but I have encountered some challenges when trying to display in one, edit in another, and print “correctly”. And every device seems to treat color profiles a little bit differently.
kllrnohj · 2h ago
> Isn’t HLG using floating point(s)?
All transfer functions can generally work on either integer range or floating point. They basically just describe a curve shape, and you can have that curve be over the range of 0.0-1.0 just as easily as you can over 0-255 or 0-1023.
Extended sRGB is about the only thing that basically requires floating point, as it specifically describes 0.0-1.0 as being equivalent to sRGB and then has a valid range larger than that (you end up with something like -.8 to 2.4 or greater). And representing that in integer domain is conceptually possible but practically not really.
> Also DCI-P3 should fit in here somewhere, as it seems to be the most standardized color space for HDR.
BT2020 is the most standardized color space for HDR. DCI-P3 is the most common color gamut of HDR displays that you can actually afford, however, but that's a smaller gamut than what most HDR profiles expect (HDR10, HDR10+, and "professional" DolbyVision are all BT2020 - a wider gamut than P3). Which also means most HDR content specifies a color gamut it doesn't actually benefit from having as all that HDR content is still authored to only use somewhere between the sRGB and DCI-P3 gamut since that's all anyone who views it will actually have.
The math uses real numbers but table 2-4 ("Digital representation") discusses how the signal is quantized to/from analog and digital. The signal is quantized to integers.
This same quantization process is done for sRGB, BT.709, BT.2020, etc. so it's not unique to HLG. It's just how digital images/video are stored.
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 lose color resolution in super dark color. As a photographer, with HDR you can re-expose the image when you display/print it, where previously that wasn’t possible. Previously when you took a photo, if you over-exposed it or under-exposed it, you were stuck with what you got. Capturing HDR gives the photographer one degree of extra freedom, allowing them to adjust exposure after the fact. Ansel Adams wasn’t using HDR in the same sense we’re talking about, he was just really good at capturing the right exposure for his medium without needing to adjust it later. There is a very valid argument to be made for doing the work up-front to capture what you’re after, but ignoring that for a moment, it is simply not possible to re-expose Adams’ negatives to reveal color detail he didn’t capture. That’s why he’s not using HDR, and why saying he is will only further muddy the water.
Creative power is still in your hands versus some tone mapper's guesses at your intent.
Can people go overboard? Sure, but thats something they will do regardless of any hdr or lack thereof.
On an aside its still rough that just about every site that touches gain map (adaptive HDR as this blog calls them) HDR images will lose that metadata if they need to scale, recompress, or transform the images otherwise. Its led me to just make my own site, but also to handle what files a client gets a bit smarter . For instance if a browser doesnt support .jxl or .avif images, im sure it wont want an hdr jpeg either, thats easy to handle on a webserver.
It's late night here so I was reading this article in dark mode, at a low display brightness - and when I got to the HDR photos I had to turn down my display even more to not strain my eyes, then back up again when I scrolled to the text.
For fullscreen content (games, movies) HDR is alright, but for everyday computing it's a pretty jarring experience as a user.
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, because bad HDR likely makes view counts go up.
As for the HDR photos in the post, well, those are a bit strong to show what HDR can do. That's why the Mark III beta includes a much tamer HDR grade.
For anyone else who was confused by this, it seems to be a client-side audio compressor feature (not a server-side adjustment) labeled as "Stable Volume". On the web, it's toggleable via the player settings menu.
https://support.google.com/youtube/answer/14106294
I can't find exactly when it appeared but the earliest capture of the help article was from May 2024, so it is a relatively recent feature: https://web.archive.org/web/20240523021242/https://support.g...
I didn't realize this was a thing until just now, but I'm glad they added it because (now that I think about it) it's been awhile since I felt the need to adjust my system volume when a video was too quiet even at 100% player volume. It's a nice little enhancement.
Another related parallel trend recently is that bad AI images get very high view and like counts, so much so that I've lost a lot of motivation for doing real photography because the platforms cease to show them to anyone, even my own followers.
I set my screen brightness to a certain level for a reason. Please don’t just arbitrarily turn up the brightness!
There is no good way to disable HDR on photos for iPhone, either. Sure, you can turn off the HDR on photos on your iphone. But then, when you cast to a different display, the TV tries to display the photos in HDR, and it won’t look half as good.
You might be on to something there. Technically, HDR is mostly about profile signaling and therefore about interop. To support it in mpeg dash or hls media you need to make sure certain codec attributes are mentioned in the xml or m3u8 but the actual media payload stays the same.
Any bit or Bob being misconfigured or misinterpreted in the streaming pipeline will result in problems ranging from slightly suboptimal experience to nothing works.
Besides HDR, "spatial audio" formats like Dolby Atmos are notorious for interop isuues
On both Android & iOS/MacOS it's not that HDR is ignoring your screen brightness, but rather the brightness slider is controlling the SDR range and then yes HDR can exceed that, that's the singular purpose of HDR to be honest. All the other purported benefits of HDR are at best just about HDR video profiles and at worst just nonsense bullshit. The only thing HDR actually does is allow for brighter colors vs. SDR. When used selectively this really enhances a scene. But restraint is hard, and most forms of HDR content production are shit. The HDR images that newer iPhones and Pixel phones are capturing are generally quite good because they are actually restrained, but then ironically both of them have horrible HDR video that's just obnoxiously bright.
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)
I think it's because no one wants it.
In contrast, my TV will change brightness modes to display HDR content and disables some of the brightness adjustments when displaying HDR content. It can be very uncomfortably bright in a dark room while being excessively dim in a bright room. It requires adjusting settings to a middle ground resulting in a mixed/mediocre experience overall. My wife’s laptop is the worst of all our devices, while reviews seem to praise the display, it has an overreactive adaptive brightness that cannot be disabled (along with decent G2G response but awful B2W/W2B response that causes ghosting).
"we finally explain what HDR actually means"
Then spends 2/3rds of the article on a tone mapping expedition, only to not address the elephant in the room, that is the almost complete absence of predictable color management in consumer-grade digital environments.
UIs are hardly ever tested in HDR: I don't want my subtitles to burn out my eyes in actual HDR display.
It is here, where you, the consumer, are as vulnerable to light in a proper dark environment for movie watching, as when raising the window curtains on a bright summer morning. (That brightness abuse by content is actually discussed here)
Dolby Vision and Apple have the lead here as a closed platforms, on the web it's simply not predictably possible yet.
Best hope is the efforts of the Color on the Web Community Group from my impression.
https://github.com/w3c/ColorWeb-CG
No. Because it's written for the many casual photographers we've spoken with who are confused and asked for an explainer.
> Then spends 2/3rds of the article on a tone mapping expedition, only to not address the elephant in the room, that is the almost complete absence of predictable color management in consumer-grade digital environments.
That's because this post is about HDR and not color management, which is different topic.
To be fair, it would be pretty weird if you found your own post off-putting :P
On the HN frontpage, people are likely thinking of one of at least three things:
HDR as display tech (hardware)
HDR as wide gamut data format (content)
HDR as tone mapping (processing)
...
So when the first paragraph says we finally explain what HDR actually means, it set me off on the wrong foot—it comes across pretty strongly for a term that’s notoriously context-dependent. Especially in a blog post that reads like a general explainer rather than a direct Q&A response when not coming through your apps channels.
Then followed up by The first HDR is the "HDR mode" introduced to the iPhone camera in 2010. caused me to write the comment.
For people over 35 with even the faintest interest in photography, the first exposure to the HDR acronym probably didn’t arrive with the iPhone in 2010, but HDR IS equivalent to Photomatix style tone mapping starting in 2005 as even mentioned later. The ambiguity of the term is a given now. I think it's futile to insist one meaning in non-scientific informal communication.
So the age correlation of what HDR means to you users might be some interesting thing to explore.
It get's a lot better after that. That said, I really did enjoy the depth. The dive into the classic dodge and burn and the linked YouTube piece. One explainer at a time makes sense—and tone mapping is a good place to start. Even tone mapping is fine in moderation :)
High dynamic resolution has always been about tone mapping. Post-sRGB color profile support is called “Wide color” these days, has been available for twenty years or more on all DSLR cameras (such as Nikon ProPhoto RGB supported in-camera on my old D70), and has nothing to do with the dynamic range and tone mapping of the photo. It’s convenient that we don’t have to use EXR files anymore, though!
An HDR photo in sRGB will have the same defects beyond peak saturation at any given hue point, as an SDR photo in sRGB would, relative to either in DCI-P3 or ProPhoto. Even a two-bit black-or-white “what’s color? on or off pixels only” HyperCard dithered image file can still be HDR or SDR. In OKLCH, the selected luminosity will also impact the available chroma range; at some point you start spending your new post-sRGB peak chroma on luminosity instead; but the exact characteristic of that tradeoff at any given hue point is defined by the color profile algorithm, not by whether the photo is SDR or HDR, and the highest peak saturation possible for each hue is fixed, whatever luminosity it happens to be at.
I predict HDR content on the web will eventually be disabled or mitigated on popular browsers similarly to how auto-playing audio content is no longer allowed [1]
Spammers and advertisers haven't caught on yet to how abusively attention grabbing eye-searingly bright HDR content can be, but any day now they will and it'll be everywhere.
1. https://hacks.mozilla.org/2019/02/firefox-66-to-block-automa...
Color management and handling HDR in UIs is probably a bit out of scope.
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.
If I enable HDR the Firefox ones become a gray mess vs the lights feeling like actual lights in Safari.
Second, the HDR effect seems to be implemented in a very crude way, which causes the whole Android UI (including the Android status bar at the top) to become brighter when HDR content is on screen. That's clearly not right. Though, of course, this might also be some issue of Android rather than Chrome, or perhaps of the Qualcomm graphics driver for my Adreno GPU, etc.
edit: Ah, nevermind. It seems Firefox is doing some sort of post-processing (maybe bad tonemapping?) on-the-fly as the pictures start out similar but degrade to washed out after some time. In particular, the "OVERTHROW BOXING CLUB" photo makes this quite apparent.
That's a damn shame Firefox. C'mon, HDR support feels like table stakes at this point.
edit2: Apparently it's not table stakes.
> Browser support is halfway there. Google beat Apple to the punch with their own version of Adaptive HDR they call Ultra HDR, which Chrome 14 now supports. Safari has added HDR support into its developer preview, then it disabled it, due to bugs within iOS.
at which point I would just say to `lux.camera` authors - why not put a big fat warning at the top for users with a Firefox or Safari (stable) browser? With all the emphasis on supposedly simplifying a difficult standard, the article has fallen for one of its most famous pitfalls.
"It's not you. HDR confuses tons of people."
Yep, and you've made it even worse for a huge chunk of people. :shrug: Great article n' all just saying.
This. I can always tell when someone "gets" software development when they either understand (or don't) that computers can't read minds or infer intent like a person can.
It didn't take very long to learn, and it turned out to be extremely important in the work I did during the early days at Waymo and later at Motional.
I wanted to pass along this fun video from several years ago that discusses HDR: https://www.youtube.com/watch?v=bkQJdaGGVM8 . It's short and fun, I recommend it to all HN readers.
Separately, if you want a more serious introduction to digital photography, I recommend the lectures by Marc Levoy from his Stanford course: https://www.youtube.com/watch?v=y7HrM-fk_Rc&list=PL8ungNrvUY... . I believe he runs his own group at Adobe now after leading a successful effort at Google making their pixel cameras the best in the industry for a couple of years. (And then everyone more-or-less caught up, just like with most tech improvements in the history of smartphones).
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.
Don't feel like you have to. I bought a giant fancy TV with it, and even though it's impressive, it's kinda like ultra-hifi-audio. I don't miss it when I watch the same show on one of my older TVs.
If you ever do get it, I suggest doing for a TV that you watch with your full attention, and watching TV / movies in the dark. It's not very useful on a TV that you might turn on while doing housework; but very useful when you are actively watching TV with your full attention.
Like a lot of things, it’s weird how some people are more sensitive to visual changes. For example:
- At this point, I need 120hz displays. I can easily notice when my wife’s phone is in power saver mode at 60hz.
- 4k vs 1080p. This is certainly more subtle, but I definitely miss detail in lower res content.
- High bitrate. This is way more important than 4k vs 1080p or even HDR. But it’s so easy to tell when YouTube lowers the quality setting on me, or when a TV show is streaming at a crappy bitrate.
- HDR is tricky, because it relies completely on the content creator to do a good job producing HDR video. When done well, the image basically sparkles, water looks actually wet, parts of the image basically glow… it looks so good.
I 100% miss this HDR watching equivalent content on other displays. The problem is that a lot of content isn’t produced to take advantage of this very well. The HDR 4k Blu-ray of several Harry Potter movies, for example, has extremely muted colors and dark scenes… so how is the image going to pop? I’m glad we’re seeing more movies rely on bright colors and rich, contrasty color grading. There are so many old film restorations that look excellent in HDR because the original color grade had rich, detailed, contrasty colors.
On top of that, budget HDR implementations, ESPECIALLY in PC monitors, just don’t get very bright. Which means their HDR is basically useless. It’s impossible to replicate the “shiny, wet look” of really good HDR water if the screen can’t get bright enough to make it look shiny. Plus, it needs to be selective about what gets bright, and cheap TVs don’t have a lot of backlighting zones to make that happen very well.
So whereas I can plug in a 4k 120hz monitor and immediately see the benefit in everything I do for normal PC stuff, you can’t get that with HDR unless you have good source material and a decent display.
Also in my country (Italy) TV transmissions are 1080i at best, a lot are still 570i (PAL resolution). Streaming media can be 4K (if you have enough bandwidth to stream it at that resolution, which I don't have at my house). Sure, if you download pirated movies you find it at 4K, and if you have the bandwidth to afford it... sure.
But even there, sometimes is better a well done 1080p movie than an hyper compressed 4K one, since you see compression artifacts.
To me 1080p, and maybe even 720p, is enough for TV vision. Well, sometimes I miss the CRT TVs, they where low resolution but for example had a much better picture quality than most modern 4K LCD TV where black scenes are gray (I know there is OLED, but is too expensive and has other issues).
I also have a screen which has a huge gamut and blows out colors in a really nice way (a bit like the aftereffects of hallucinogens, it has colors other screens just don't) and you don't have to touch any settings.
My OLED TV has HDR and it actually seems like HDR content makes a difference while regular content is still "correct".
I think the industry is strangling itself putting "DisplayHDR 400" certification on edgelit/backlit LCD displays. In order for HDR to look "good" you either need high resolution full array local dimming backlighting (which still isn't perfect), or a panel type that doesn't use any kind of backlighting like OLED.
Viewing HDR content on these cheap LCDs often looks worse than SDR content. You still get the wider color gamut, but the contrast just isn't there. Local dimming often loses all detail in shadows whenever there is something bright on the screen.
People in the HN echo chamber over-estimate hardware adoption rates. For example, there are millions of people who went straight from CDs to streaming, without hitting the iPod era.
A few years ago on HN, there was someone who couldn't wrap their brain around the notion that even though VCRs were invented in the early 1960's that in 1980, not everyone owned one, or if they did, they only had one for the whole family.
Normal people aren't magpies who trash their kit every time something shiny comes along.
Point of clarification: While the technology behind the VCR was invented in the '50s and matured in the '60s, consumer-grade video tape systems weren't really a thing until Betamax and VHS arrived in 1975 and 1976 respectively.
Early VCRs were also incredibly expensive, with prices ranging from $3,500 to almost $10,000 after adjusting for inflation. Just buying into the VHS ecosystem at the entry level was a similar investment to buying an Apple Vision Pro today.
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.
I finished high school in 2001 and didn't immediately go to college, so I just didn't have a need for a personal music player anymore. I was nearly always at home or at work, and I drove a car that actually had an MP3 CD player. I felt no need to get an iPod.
In 2009, I started going to college, but then also got my first smartphone, the Motorola Droid, which acted as my portable MP3 player for when I was studying in the library or taking mass transit.
If you were going to school or taking mass transit in the middle of the '00s, then you were probably more likely to have a dedicated MP3 player.
1: Well my car would play MP3s burned to CDs in its CD player; not sure if that counts.
As for tone mapping, I think the examples they show tend way too much towards flat low-local-contrast for my tastes.
I'm a huge fan of Helldivers 2, but playing the game in HDR gives me a headache: the muzzle flash of weapons at high RPMs on a screen that goes to 240hz is basically a continuous flashbang for my eyes.
For a while, No Mans' Sky in HDR mode was basically the color saturation of every planet dialed up to 11.
The only game I've enjoyed at HDR was a port from a console, Returnal. The use of HDR brights was minimalistic and tasteful, often reserved for certain particle effects.
I stopped playing that game for several years, and when I went back to it, the color and brightness had been wrecked to all hell. I have heard that it's received wisdom that gamers complain that HDR modes are "too dark", so perhaps that's part of why they ruined their game's renderer.
Some games that I think currently have good HDR:
* Lies of P
* Hunt: Showdown 1896
* Monster Hunter: World (if you increase the game's color saturation a bit from its default settings)
Some games that had decent-to-good HDR the last time I played them, a few years ago:
* Battlefield 1
* Battlefield V
* Battlefield 2042 (If you're looking for a fun game, I do NOT recommend this one. Also, the previous two are probably chock-full of cheaters these days.)
I found Helldivers 2's HDR mode to have blacks that were WAY too bright. In SDR mode, nighttime in forest areas was dark. In HDR mode? It was as if you were standing in the middle of a field during a full moon.
Everything is flattened, contrast is eliminated, lights that should be "burned white" for a cinematic feel are brought back to "reasonable" brightness with HDR, really deep blacks are turned into flat greys, etc. The end result is the flat and washed out look of movies like Wicked. It's often correlated to CGI-heavy movies, but in reality it's starting to affect every movie.
About HDR on phones, I think they are the blight of photography. No more shadows and highlights. I find they are good at capturing family moments, but not as a creative tool.
I still use it myself but I need to redo the build system and release it with an updated LibRaw... not looking forward to that.
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 phone or PC screen. The pic fails to capture what your eyes see for lighting range.
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 this is assuming an HDR monitor that's also a good match for your ambient environment. The big thing nobody really talks about wiith HDR is that it's really dominated by how dark you're able to get your surrounding environment such that you can push your display "brightness" (read: SDR whitepoint) lower and lower. OLED HDR monitors, for example, look fantastic in SDR and fantastic in HDR in a dark room, but if you have typical office lighting and so you want an SDR whitepoint of around 200-300 nits? Yeah, they basically don't do HDR at all anymore at that point.
The difference is absolutely stunning in some games.
In MS Flight Simulator 2024, going from SDR to HDR goes from looking like the computer game it is to looking life-like. Deeper shadows with brighter highlights makes the scene pop in ways that SDR just can't do.
EDIT: You'll almost certainly need an OLED monitor to really appreciate it, though. Local dimming isn't good enough.
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.
I use a mini-led monitor, and its quite decent, except for starfields, & makes it very usable even in bright conditions, and HDR video still is better in bright conditions than the equivalent SDR video.
https://github.com/dylanraga/win11hdr-srgb-to-gamma2.2-icm
Like totally washed out
You know the 0-10 brightness slider you have to pick at the start of a game? Imagine setting it to 0 and still being able to spot the faint dark spot. The dynamic range of things you can see is so much expanded.
Early HDR screens were very limited (limited dimming zones, buggy implementation) but if you get one post 2024 (esp the oled ones) they are quite decent. However it needs to be supported at many layers: not just the monitor, but also the operating system, and the content. There are not many games with proper HDR implementation; and even if there is, it may be bad and look worse — the OS can hijack the rendering pipeline and provide HDR map for you (Nvidia RTX HDR) which is a gamble: it may look bleh, but sometimes also better than the native HDR implementation the game has).
But when everything works properly, wow it looks amazing.
Note that HDR only actually changes how bright things can get. There's zero difference in the dark regions. This is made confusing because HDR video marketing often claims it does, but it doesn't actually. HDR monitors do not, in general, have any advantage over SDR monitors in terms of the darks. Local dimming zones improve dark contrast. OLED improves dark contrast. Dynamic contrast improves dark contrast. But HDR doesn't.
This matches my experience; 0 to 5 look identically black if I turn off HDR
But like if you can't see a difference between 0 to 5 in a test pattern like this https://images.app.goo.gl/WY3FhCB1okaRANc28 in SDR but you can in HDR then that just means your SDR factory calibration is bad, or you've fiddled with settings that broke it.
As others here have said, OLED monitors are generally excellent at reproducing a HDR signal, especially in a darker space. But they're terrible for productivity work because they'll get burned in for images that don't change a lot. They're fantastic for movies and gaming, though.
There are a few good non-OLED HDR monitors, but not many. I have an AOC Q27G3XMN; its a 27" 1440p 180hz monitor that is good for entry-level HDR, especially in brighter rooms. It has over 1000 nits of brightness, and no major flaws. It only has 336 backlight zones, though, so you might notice some blooming around subtitles or other fine details where there's dark and light content close together. (VA panels are better than IPS at suppressing that, though.) It's also around half the price of a comparable OLED.
Most of the other non-OLED monitors with good HDR support have some other deal-breaking flaws or at least major annoyances, like latency, screwing up SDR content, buggy controls, etc. The Monitors Unboxed channel on YouTube and rtngs.com are both good places to check.
My current monitor is an OLED and HDR in games looks absolutely amazing. My previous was an IPS that supported HDR, but turning it on caused the backlight to crank to the max, destroying black levels and basically defeating the entire purpose of HDR. Local dimming only goes so far.
I'd also be interested in hearing whether it makes sense to look into OLED HDR 400 screens (Samsung, LG) or is it really necessary to get an Asus ProArt which can push the same 1000 nits average as the Apple XDR display (which, mind you, is IPS).
If you have say a 400 nits display the HDR may actually look worse than SDR. So it really depends on your screen.
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.
Also the maximum brightness isn't even that bright at 800 nits, so no HDR content really looks that different. I think newer OLEDs are brighter though. I'm still happy with the screen in general, even in SDR the OLED really shines. But it made me aware not all HDR screens are equal.
Also, in my very short experiment using HDR for daily work I ran into several problems, the most serious of which was the discovery that you can no longer just screenshot something and expect it to look the same on someone else's computer.
To be pedantic, this has always been the case... Who the hell knows what bonkers "color enhancement" your recipient has going on on their end?
But (more seriously) it's very, very stupid that most systems out there will ignore color profile data embedded in pictures (and many video players ignore the same in videos [0]). It's quite possible to tone-map HDR stuff so it looks reasonable on SDR displays, but color management is like accessibility in that nearly noone who's in charge of paying for software development appears to give any shits about it.
[0] A notable exception to this is MPV. I can't recommend this video player highly enough.
And thats now that all the LEDs are still fresh. I can't imagine how bad it will be in a few years.
Also, a lot of Software doesn't expect the subpixel arrangement, so text will often look terrible.
For desktop work, don't bother unless your work involves HDR content.
On my Macbook Pro only activates when it needs to but honestly I've only seen one video [1] that impressed me with it, the rest was completely meh. Not sure if its because it's mostly iPhone photography you see in HDR which is overall pretty meh looking anyway.
[1] https://www.youtube.com/watch?v=UwCFY6pmaYY I understand this isn't a true HDR process but someone messing with it in post, but it's the only video I've seen that noticeably shows you colors you can't see on a screen otherwise.
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?
https://docs.krita.org/en/general_concepts/colors/bit_depth....
https://docs.krita.org/en/general_concepts/colors/color_spac...
https://docs.krita.org/en/general_concepts/colors/scene_line...
All this aside, HDR and high brightness are different things - HDR is just a representational thing. You can go full send on your SDR monitor as well, you'll just see more banding. The majority of the article is just content marketing about how they perform automatic tonemapping anyways.
That’s a consequence of https://en.wikipedia.org/wiki/Adaptation_(eye). If you look at 1000 nits on a display in bright sunlight, with your eyes adapted to the bright surroundings, the display would look rather dim.
A lot of these design flaws are fixed by Firefox's picture in picture option but for some reason, with the way you coded it, the prompt to pop it out as PIP doesn't show up
Literal snort.
From a technical point of view, HDR is just a set of standards and formats for encoding absolute-luminance scene-referred images and video, along with a set of standards for reproduction.
https://www.graphics.cornell.edu/~bjw/rgbe.html
It uses a type of floating point, in a way, but it’s a shared 8 bit exponent across all 3 channels, and the channels are still 8 bits each, so the whole thing fits in 32 bits. Even the .txt file description says it’s not “floating point” per-se since that implies IEEE single precision floats.
Cameras and displays don’t typically use floats, and even CG people working in HDR and using, e.g., OpenEXR, might use half floats more often that float.
Some standards do exist, and it’s improving over time, but the ideas and execution of HDR in various ways preceded any standards, so I think it’s not helpful to define HDR as a set of standards. From my perspective working in CG, HDR began as a way to break away from 8 bits per channel RGB, and it included improving both color range and color resolution, and started the discussion of using physical metrics as opposed to relative [0..1] ranges.
And no, it's not necessarily absolute luminance. PQ is absolute, HLG is not.
Also DCI-P3 should fit in here somewhere, as it seems to be the most standardized color space for HDR. I would share more insight, if I had it. I thought I understood color profiles well, but I have encountered some challenges when trying to display in one, edit in another, and print “correctly”. And every device seems to treat color profiles a little bit differently.
All transfer functions can generally work on either integer range or floating point. They basically just describe a curve shape, and you can have that curve be over the range of 0.0-1.0 just as easily as you can over 0-255 or 0-1023.
Extended sRGB is about the only thing that basically requires floating point, as it specifically describes 0.0-1.0 as being equivalent to sRGB and then has a valid range larger than that (you end up with something like -.8 to 2.4 or greater). And representing that in integer domain is conceptually possible but practically not really.
> Also DCI-P3 should fit in here somewhere, as it seems to be the most standardized color space for HDR.
BT2020 is the most standardized color space for HDR. DCI-P3 is the most common color gamut of HDR displays that you can actually afford, however, but that's a smaller gamut than what most HDR profiles expect (HDR10, HDR10+, and "professional" DolbyVision are all BT2020 - a wider gamut than P3). Which also means most HDR content specifies a color gamut it doesn't actually benefit from having as all that HDR content is still authored to only use somewhere between the sRGB and DCI-P3 gamut since that's all anyone who views it will actually have.
The math uses real numbers but table 2-4 ("Digital representation") discusses how the signal is quantized to/from analog and digital. The signal is quantized to integers.
This same quantization process is done for sRGB, BT.709, BT.2020, etc. so it's not unique to HLG. It's just how digital images/video are stored.