Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

What is HDR, anyway?

lux.camera

Post reply on HN
Print view View original

51–60 of 352 posts

Re: What is HDR, anyway?

#51

Post by SebastianKra »

the__alchemist wrote: post #4

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

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.

Re: What is HDR, anyway?

#52

Post by kllrnohj »

eschatology wrote: post #24
the__alchemist wrote: post #4

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

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. Ho…

> 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.

Re: What is HDR, anyway?

#53

Post by bookofjoe »

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.

Re: What is HDR, anyway?

#54

Post by throwaway314155 »

echo_time wrote: post #7

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?

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.

Re: What is HDR, anyway?

#55

Post by klausa »

mxfh wrote: post #22

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…

It's a blog for a (fancy) iPhone camera app.

Color management and handling HDR in UIs is probably a bit out of scope.

Re: What is HDR, anyway?

#56

Post by kllrnohj »

skhameneh wrote: post #42
cornstalks wrote: post #17

Earlier quoted context omitted.

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.

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.

> 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.

Re: What is HDR, anyway?

#57

Post by puzzlingcaptcha »

lordleft wrote: post #31
mxfh wrote: post #22

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…

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.

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.

Re: What is HDR, anyway?

#58

Post by c-fe »

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.

Re: What is HDR, anyway?

#59

Post by sandofsky »

mxfh wrote: post #22

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…

> 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.

Post reply on HN