HDR imaging and HDR video are different techniques to produce more dynamic range. HDR imaging is compositing multiple images and using tone mapping to fit more dynamic range into regular image. If have a HDR display that can show the extra dynamic range, then don't need to do the tone mapping which tends to be the fake looking part.

HDR video is usually recorded with the higher range. Are there videos where high dynamic range is compressed into standard dynamic range? Or where HDR is synthesized from regular video?

Most of the TV and movies you've been watching since things went digital are cases where 'high dynamic range' has been jammed into a standard dynamic range container (most features and high-end drama would shoot either raw or record sensor data using some form of logarithmic transfer function to maximize the amount of information per bit or encoding). All information coming from the debayered raw or camera's widest 'record gamut' that's outside of the Rec.709 (or P3 for cinema) colourspace has simply been mapped down to an equivalent Rec. 709 / P3 value via a Look Up Table, graded down to fit within the output gamut, or simply clamped/thrown away.

HDR now gives a lot more to play with from a post production standpoint (when shot raw or using some logarithmic transfer function to encode the sensor data), as more of the picture information coming off the camera sensor can be utilised (where exposure, recording format and compression allow)

Isn't the whole point of HDR to make things even more lifelike and immersive?

From a technical standpoint 8-bits-per-color was never enough to display anywhere near the full spectrum. I've also personally been peeved with the flat, weak-ass dynamic range on most TVs and anything to add a few bits to the stream seems like a win in my book.

Unless, somehow, this ends up stuck in a rut in the uncanny valley (or someone wants to make the filesize argument), how is improved dynamic range a bad thing?

Not only that but it also allows to display colors outside of the sRGB (Rec. 709) gamut.

No, displays which can support colors outside of BT.709 allow this to happen. HDR processing is just a post-processing gimmick used by Hollywood to make things look even less realistic and more plastic.

Strictly speaking you are right, but in practice HDR term is used to describe both HDR and wide color gamut.

> HDR processing is just a post-processing gimmick

Can you explain how it's a gimmick?

If you are confusing HDR for the process of taking an existing Rec. 709 signal and gamut mapping into a subset of Rec. 2020, I agree that is a bit gimmicky.

This (ab)use of the technology has nothing to do with the HDR standards however, what true HDR video is, nor what material mastered for HDR is or is capable of, and shouldn't define how you see the technology (or present it to others).

You can't address the full color gamut without increased signaling bandwidth, which HDR provides. Or do you really want your 10bpp TV outputting 8bpp?

Of course not. If you want to increase the dynamic range of color, all you have to do is increase the sampling bit depth of the picture being captured.

HDR is a specific technique which involves cheaply processing pixels to fit a different color curve than it was captured in. It's not lifelike, it's candy-like.

I think you may have some technology terminology confusion. There are 4K panels that really can display colors that are physically impossible for other panels to display.

It is true that these systems ship with fake-o postprocessing to take conventional content and smear them into these new colors, but that's a stopgap, and you aren't actually obligated to use them, you know. Just like TVs tend to ship in what I call "claw your eyes out mode" for display, but it's the work of just a few seconds to turn them back to something sane for any decent quality panel. (There are certainly panels that have no decent quality setting, no matter how much you fiddle; if you care, do some research. I do and did.)

Per what I see of your other comment, whether you like it or not, there are standards being called "HDR" that includes true expanded gamut support: https://en.wikipedia.org/wiki/High-dynamic-range_video#Stand...

No, the new standard is called "HDR10" [1] and it standardizes the use of BT.2020.

Can we not even trust people on HN to only speak to what they know about?

[1] https://en.wikipedia.org/wiki/High-dynamic-range_video#HDR10

HDR10 is an instance of an HDR standard. All of them include higher gamut color except SL-HDR1, which is not itself an HDR standard but an encoding mechanism for embedding HDR in SDR.

So it appears all the "HDR" standards include higher gamut settings, making the simplification true enough for me to call it correct.

> Can we not even trust people on HN to only speak to what they know about?

Not any more than we can trust the old curmudgeons to not beat their knowledge into others by force I guess.

I'm not an old curmudgeon - I am a young guy who knows a lot about digital media technologies and their underlying principles.

Don't trivialize my specialized knowledge by saying I'm old. The only reason you can watch anything on youtube today is because people like me cared about standards and best practices -- and most importantly, cared about being right about things.

Typical "break stuff, stop reading books" mentality of engineers my age. It's sad.

"Old curmudgeon" has nothing to do with age, but attitude. You might be young, but doesn't mean you don't have a "get off my lawn" attitude throughout this thread.

That matters why?

More often than not the old curmudgeons are right, young shits just don't want to accept it

I agree completely and am often called a curmudgeon myself. That doesn't mean the attitude isn't off putting to others, even when I myself am doing it.

What's wrong with being off-putting? Why do so many seem to want to embrace this disgusting care-bear idea of discourse? A discussion isn't lively without at least one provocateur.

There are three standards - HDR10, Dolby Vision and HLG. Apple TV will support the first two, the last one wasn't mentioned.

They did the same thing for half a century with vinyl, calling it "equalization", because the response curve for vinyl records doesn't really line up with human perception. Ironically, there were so many competing equalization curves that the RIAA finally had to step in and impose their standard (the "RIAA equalization curve"), of which all phono preamps follow to this day.

I don't know the technical details of HDR but this sort of curve compressions is a common trick for matching a medium to our perception. Unless important info is lost, who cares?

Or, can anyone present a head-to-head comparison between 10bpp+ or "HDR"?

The RIAA curve was used to standardize the frequency response of vinyl records.

HDR post-processing is not being used to standardize the color subsampling accuracy of digital video files. It is being used to coerce pixels to following one particular subset of high-gamut color curvatures. It is NOT the same thing as 10bit color, nor as wide-gamut color spaces. It is a post-production trick used to make your eyes more enticed by the picture.

It is not about higher fidelity picture, it is about higher engagement viewers.

Fair enough, I stand corrected on my wide-gamut assertions. If HDR is only about hacking the luminance channel that is rather... disappointing. Here I was thinking wide-gamut was finally becoming fashionable...

Still, I don't think HDR is a net negative even if its just improvements in luminance -- LCD TVs are especially bad at representing shadows and I have grown tired of watching thousand-dollar TVs treat dark images like a cheap laptop. Was hoping HDR would do something about that :/

BT2020/2100 covers 'Wide Gamut' and 'Higher luminance' (PQ / SMPTE ST:2084) - both of these in tandem are at the core of all existing HDR standards (aside from HLG which I'll save for another discussion).

Bit depth will give you a value per color channel between zero (black) and the upper bound for that bit depth (2^n - white). How the image data is encoded in those values is very much standardized for all display colourspaces (though whether the hardware is capable of displaying the full range of those values correctly is a different story).

HDR is certainly not a fad - the current crop of displays are nowhere close to being able to display the full potential of the technology yet (100% of Rec.2020 gamut @ 10,000 nits)

AndrewUnmuted - are you perhaps confusing 'true' HDR with upscaled / gamut mapped rec. 709 material? e.g. taking an existing rec. 709 master and mapping the color to a larger colourspace?

Netflix, Amazon and several other OTT providers have their original content mastered in true HDR from the get go - no post processing 'tricks'. The main limiting factor is the acquisition source, which is why Netflix have gone down the route of specifying acceptable cameras for use on their original content productions.

Hi, as an owner of an OLED HDR tv, I heartily disagree. Have you seen Planet Earth 2? 3D was a gimmick. HDR is here to stay.

Planet Earth 2 was shot in UHD [1] - there was no LUT-based 8bpp->10bpp upsampling needed because it was already captured in BT.2020!!

What the hell is wrong with everybody here?

[1] https://en.wikipedia.org/wiki/Ultra-high-definition_televisi...

I'm not sure what your point is. BT.2020 is 10- or 12- bit, so an tv that can take advantage of HDR (i.e. 10 bit) will most accurately match what was filmed.

e: I feel like you might be confusing 'HDR' with 'HDR upsampling'.