Comment by mxfh
2 days 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.
>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
Me, routinely, reading things I wrote a while ago: what is this dreck
> That's because this post is about HDR
It's about HDR from the perspective of still photography, in your app, on iOS, in the context of hand-held mobile devices. The post's title ("What Is HDR, Anyway?"), content level and focus would be appropriate in the context of your company's social media feeds for users of your app - which is probably the audience and context it was written for. However in the much broader context of HN, a highly technical community whose interests in imaging are diverse, the article's content level and narrow focus aren't consistent with the headline title. It seems written at a level appropriate for novice users.
If this post was titled "How does Halide handle HDR, anyway?" or even "How should iOS photo apps handle HDR, anyway?" I'd have no objection about the title's promise not matching the content for the HN audience. When I saw the post's headline I thought "Cool! We really need a good technical deep dive into the mess that is HDR - including tech, specs, standards, formats, content acquisition, distribution and display across content types including stills, video clips and cinematic story-telling and diverse viewing contexts from phones to TVs to cinemas to VR." When I started reading and the article only used photos to illustrate concepts best conveyed with color gradient graphs PLUS photos, I started to feel duped by the title.
(Note: I don't use iOS or your app but the photo comparison of the elderly man near the end of the article confused me. From my perspective (video, cinematography and color grading), the "before" photo looks like a raw capture with flat LUT (or no LUT) applied. Yet the text seemed to imply Halide's feature was 'fixing' some problem with the image. Perhaps I'm misunderstanding since I don't know the tool(s) or workflow but I don't see anything wrong with the original image. It's what you want in a flat capture for later grading.)
> It's about HDR from the perspective of still photography, in your app, on iOS, in the context of hand-held mobile devices.
It's from the perspective of still photography, video, film, desktop computing, decades of research papers, and hundreds of years of analog photography, condensed into something approachable.
> However in the much broader context of HN, a highly technical community whose interests in imaging are diverse, the article's content level and narrow focus aren't consistent with the headline title. It seems written at a level appropriate for novice users.
"On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity"
To be clear, I didn't submit the post, and I never submit my posts. I don't care if my posts make a splash here, and kind of dread when they do because anything involving photography or video attracts the most annoying "well actually" guys on the Internet.
> When I saw the post's headline I thought "Cool! We really need a good technical deep dive into the mess that is HDR - including tech, specs, standards, formats, content acquisition, distribution and display across content types including stills, video clips and cinematic story-telling and diverse viewing contexts from phones to TVs to cinemas to VR."
The post is called, "What is HDR," and the introduction explains the intended audience. That audience is much larger than "people who want to read about ITU-R Recommendation BT.2100." But if you think people are interested in a post like that, by all means write it.
> However in the much broader context of HN, a highly technical community whose interests in imaging are diverse, the article's content level and narrow focus aren't consistent with the headline title. It seems written at a level appropriate for novice users.
That is hardly the fault of the authors though. The article seems entirely appropriate for its intended audience, and they can’t control who posts it on a site like HN.
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 or police one meaning other the other in non-scientific informal communication, just use more specific terminology.
So the correlation of what HDR means or what sentiment it evokes in people by age group and self-assesed photography skill might be something worthwhile to explore.
The post 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 :)
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.
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> "The first HDR is the "HDR mode" introduced to the iPhone camera in 2010."
Yeah, I had a full halt and process exception on that line too. I guess all the research, technical papers and standards development work done by SMPTE, Kodak, et al in the 1990s and early 2000s just didn't happen? Turns out Apple invented it all in 2010 (pack up those Oscars and Emmys awarded for technical achievement and send'em back boys!)
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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.
In theory PQ specifies absolute values, but in practice it's treated as relative. Go load some PQ encoded content on an iPhone, adjust your screen brightness, and watch the HDR brightness also change. Beyond the iPhone, it would be ridiculous to render absolute values as-is, given SDR white is supposedly 100-nits; that would be unwatchable in most living rooms.
Bad HDR boils down to poor taste and the failure of platforms to rein it in. You can't fix bad HDR by switching encodings any more than you can fix global warming by switching from Fahrenheit to Celsius.
> 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.
1. https://hacks.mozilla.org/2019/02/firefox-66-to-block-automa...
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.
They haven't, but influencers certainly have, I get regular still images which are rendered as a video to get the HDR brightness boost in Instagram, etc.
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.
It's a blog for a (fancy) iPhone camera app.
Color management and handling HDR in UIs is probably a bit out of scope.
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.
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.
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?
You can for some definition of "solve", by tone-mapping all HDR content back down into an SDR range for display.
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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".
But it's not the colloquial meaning, HDR is fairly well defined by e.g. ITU-R BT.2100, which addresses colorimetry, luminance and the corresponding transfer functions.
I don't think that's the colloquial meaning. If you asked 100 people on the street to describe HDR, I doubt a single person would bring up ITU-R BT.2100.
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I think you may be operating with an idiosyncratic definition of "colloquial"
Colloquial meaning and the well defined meaning are two different things in most cases, right?
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.
It's nonsense that an image/video gets to override my screen brightness, end of story. I want that removed, not even a setting, just gone.
The photo capture HDR is good. That's a totally different thing and shouldn't have had its name stolen.