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What is HDR, anyway?

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Re: What is HDR, anyway?

#161

Post by dahart »

munificent wrote: post #157
dahart wrote: post #123

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

> The claim that Ansel Adams used HDR is super likely to cause confusion That isn't what the article claims. It says: "Ansel Adams, one of the most revered photographers of the 20th century, was a master at capturing dramatic, high dynamic range scenes." "Use HDR" (your term) is vague to the point of not meaning much of anything, but the article is clear that Adams was capturing scenes that had a high dynamic range,…

Literally the sentence preceding the one you quoted is “What if I told you that analog photographers captured HDR as far back as 1857?”.

Re: What is HDR, anyway?

#162

Post by zymhan »

dahart wrote: post #161
munificent wrote: post #157

Earlier quoted context omitted.

> The claim that Ansel Adams used HDR is super likely to cause confusion That isn't what the article claims. It says: "Ansel Adams, one of the most revered photographers of the 20th century, was a master at capturing dramatic, high dynamic range scenes." "Use HDR" (your term) is vague to the point of not meaning much of anything, but the article is clear that Adams was capturing scenes that had a high dynamic range,…

Literally the sentence preceding the one you quoted is “What if I told you that analog photographers captured HDR as far back as 1857?”.

And that quote specifically does not "lump HDR capture, HDR formats and HDR display together".

It is directly addressing capture.

Re: What is HDR, anyway?

#163

Post by caseyy »

The dad’s photo in the end in SDR looks so much better on a typical desktop IPS panel (Windows 11). The HDR photo looks like the brightness is smushed in the most awful way. On an iPhone, the HDR photo is excellent and the others look muted.

I wonder if there’s an issue in Windows tonemapping or HDR->SDR pipeline, because perceptually the HDR image is really off.

It’s more off than if I took an SDR picture of my iPhone showing the HDR image and showed that SDR picture on the said Windows machine with an IPS panel. Which tells me that the manual HDR->SDR “pipeline” I just described is better.

I think Windows showing HDR content on a non-HDR display should just pick an SDR-sized section of that long dynamic range and show it normally. Without trying to remap the entire large range to a smaller one. Or it should do some other perceptual improvements.

Then again, I know professionally that Windows HDR is complicated and hard to tame. So I’m not really sure the context of remapping as they do, maybe it’s the only way in some contingency/rare scenario.

Re: What is HDR, anyway?

#164

Post by dahart »

zymhan wrote: post #162
dahart wrote: post #161

Earlier quoted context omitted.

Literally the sentence preceding the one you quoted is “What if I told you that analog photographers captured HDR as far back as 1857?”.

And that quote specifically does not "lump HDR capture, HDR formats and HDR display together". It is directly addressing capture .

Correct. I didn’t say that sentence was the source of the conflation, I said it was the source of the Ansel Adams problem. There are other parts that mix together capture, formats, and display.

Edit: and btw I am objecting to calling film capture “HDR”, I don’t think that helps define HDR nor reflects accurately on the history of the term.

Re: What is HDR, anyway?

#165

Post by mxfh »

ddingus wrote: post #152
mxfh wrote: post #134

Earlier quoted context omitted.

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 se…

I took the post about the same way. Thought it excellent because of depth. Often, we don't get that and this topic, plus my relative ignorance on it, welcomed the post as written.

Just out of curiosity since your profile suggests your from an older cohort. Do you actively remember the Pixelmatix tone mapping era, or where you already old enough to see this as a passing fad, or was this a more niche thing than I remember?

Now I even remember the 2005 HDR HL2 Lost Coast Demo was a thing 20 years ago: https://bit-tech.net/previews/gaming/pc/hl2_hdr_overview/1/

Re: What is HDR, anyway?

#166

Post by fracus »

The article starts by saying HDR can mean different things and gives Apple's HDR vs new TV "HDR" advertsing but doesn't explain at all what the TV HDR means and how it is different, unless I missed something. I always assumed they were the same thing.

Re: What is HDR, anyway?

#167

Post by springhalo »

Uncorrelated wrote: post #149

I find the default HDR (as in gain map) presentation of iPhone photos to look rather garish, rendering highlights too bright and distracting from the content of the images. The solution I came up with for my own camera app was to roll off and lower the highlights in the gain map, which results in final images that I find way more pleasing. This seems to be somewhat similar to what Halide is introducing with their "St…

I see that it says it stores images "in an HDR format by default" but keeps referencing JPEG output. Are you using JPEG-XT? There aren't a lot of "before and after" comparisons so it's hard to know how much it's taking out. I figure those would probably hurt the reputation of the app considering its purpose is to un-pop photos, but I'm in the boat of not really being sure whether I do actually like the pop or not. Is there live-photo support, or is that something that you shouldn't expect from a artist-focused product?

Re: What is HDR, anyway?

#168

Post by dahart »

arghwhat wrote: post #153
dahart wrote: post #123

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

Arguably, even considering HDR a distinct thing is itself weird an inaccurate. All mediums have a range, and they've never all matched. Sometimes we've tried to calibrate things to match, but anyone watching SDR content for the past many years probably didn't do so on a color-calibrated and brightness calibrated screen - that wouldn't allow you to have a brightness slider. HDR on monitors is about communicating conte…

This! Yes I think you’re absolutely right. The term “HDR” is in part kind of an artifact of how digital image formats evolved, and it kind of only makes sense relative to a time when the most popular image formats and most common displays were not very sophisticated about colors.

That said, there is one important part that is often lost. One of the ideas behind HDR, sometimes, is to capture absolute values in physical units, rather than relative brightness. This is the distinguishing factor that film and paper and TVs don’t have. Some new displays are getting absolute brightness features, but historically most media display relative color values.

Re: What is HDR, anyway?

#169

Post by altairprime »

Suppafly wrote: post #146
altairprime wrote: post #131

Earlier quoted context omitted.

No; Windows 10 barely supports it, and of my hundreds of Steam games, exactly none have any code making use of it; seemingly only AAA mega-budget games have the pipeline bandwidth, but e.g. Dune Imperium and Spaceways have no reason to use it and so don’t bother. Windows 11 focused on improving wide color support which is much more critical, as any game shipping for Mac/Win already has dealt with that aspect of the p…

Nothing you're written disproves that no one wants it, if anything the fact that nothing really supports it implies that it's not a valuable feature that people are clamoring for.

Given how popular it is in modern console AAA gaming, which many people do play on PCs, one can reasonably expect that any studio desiring to target high contrast gaming — a valuable niche for stealth games, where a bright torch should absolutely stand out brightly against the darkest shadows, as well as star exploration and anything with landscapes or specular highlights — would like to be targeting HDR on PC, if only to simplify their cross-platform build and test pipelines, but cannot due to platform barriers that don’t exist for consoles.

Re: What is HDR, anyway?

#170

Post by thfuran »

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 may not be the best explanation, but I think any explanation of HDR beyond a sentence or two of definition that doesn't mention the mess that is tone mapping is entirely remiss.
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