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What is HDR, anyway?

(www.lux.camera)
789 points _kush | 1 comments | | HN request time: 0.208s | source
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mxfh ◴[] No.43984652[source]
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.

https://github.com/w3c/ColorWeb-CG

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1. altairprime ◴[] No.43986356[source]
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.