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What is HDR, anyway?

lux.camera

321–330 of 352 posts

Re: What is HDR, anyway?

#321

Earlier quoted context omitted.

The client side toggle might be new since 2024 but the volume normalisation has been a thing for a long time.

Yes, and I love it! Finally, the volume knob control was pulled from producers all about gimmicks to push their productions. There are still gimmicks, but at least they do not include music so badly clipped as to be unlistenable... hint: go get the DVD or Blu-Ray release of whatever it is and you are likely to enjoy a not clipped album. It is all about maximizing the overall sonic impact the music is capable of. Now…

I expected a moderate amount of heat directed at my comment.

No worries. I've friends in various industries doing production who hate the change.

I like it, of course. Losing the volume knob is a direct result of the many abuses.

Re: What is HDR, anyway?

#322
post #165

Earlier quoted context omitted.

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/

I was old enough to see it as the passing fad it was.

Niche, style points first kind of thing for sure.

Meta: old enough that getting either a new color not intended, or an additional one visible on screen and having the machine remain able to perform was a big deal.

Re: What is HDR, anyway?

#326

Earlier quoted context omitted.

Samsung also makes sensors for phones. IIRC some Pixels use their sensors.

I think Canon makes at least some of their sensors, and Nikon designs theirs and makes it at a third party I forget the name of that isn't Sony or Samsung but they still do use Sony stuff in a lot of their cameras. I don't know about Pentax, Panasonic or OMD (formerly Olympus)

I think folks here have some idea how expensive chip fabs are. That's why only Canon is able to make their own sensors.

Sony makes sensors for pretty much everyone else. But it's well known that other folks e.g. Nikon have been able to get better signal-to-noise with Sony-made sensors than Sony themselves. I think Panasonic used to make their own sensors but with some recent re-org, that got spun out.

It's been widely rumored that Leica uses Sony sensors, but this gets repeatedly denied by people claiming inside information. We know that Leica was getting 24MP CMOS sensors from CMOSIS in the 2012 timeframe, but CMOSIS has since been acquired by OSRAM, and there hasn't been any verifiable information since then, whether confirming or denying a continued business relationship.

Re: What is HDR, anyway?

#327
post #288

Earlier quoted context omitted.

Sorry man, you seem really defensive, I didn’t mean to put you on edge. Okay, if you are calling the scenes “HDR” then I’m happy to rescind my critique about Ansel Adams and switch instead to pointing out that “HDR” doesn’t refer to the range of the scene, it refers to the range capability of a digital capture process. I think the point ultimately ends up being the same either way. Hey where is HDR defined as an adje…

You opened this thread arguing that Ansel Adams didn't "use HDR." I linked you to a seminal research paper which argues that he tone mapped HDR content, and goes on to implement a tone mapper based on his approach. This all seems open and shut. > I’m happy to rescind my critique about Ansel Adams Great, I'm done. > and switch instead to pointing out that “HDR” doesn’t refer to the range of the scene Oh god. Here's th…

Hehe outside is “HDR content”? To me that still comes off as confused about what HDR is. I know you aren’t, but that’s what it sounds like. A sunny day has a high dynamic range for sure, but the acronym HDR is a term of art that implies more than that. Your article even explains why.

Tone mapping doesn’t imply HDR. Tone mapping is always present, even in LDR and SDR workflows. The paper you cited explicitly notes the idea is to “extend” Adams’ zone system to very high dynamic range digital images, more than what Adams was working with, by implication.

So how is a “window of luminance values” different from a dynamic range, exactly? Why did you make the incorrect and obviously silly assumption that I was suggesting a camera’s aperture changes the outdoor scene’s dynamic range rather than what I actually said, that it changes the exposure? Your description of what a camera does is functionally identical. I’m kinda baffled as to why you’re arguing this part that we both understand, using hyperbole.

I hope you have a better day tomorrow. Good luck with your app. This convo aside, I am honestly rooting for you.

Re: What is HDR, anyway?

#328

Earlier quoted context omitted.

While it isn't touched on in the post, I think the issue with feeds is that platforms like Instagram have no interest in moderating HDR. For context: YouTube automatically edits the volume of videos that have an average loudness beyond a certain threshold. I think the solution for HDR is similar penalization based on log luminance or some other reasonable metric. I don't see this happening on Instagram any time soon,…

> I think the solution for HDR is similar penalization based on log luminance or some other reasonable metric. I completely understand the desire to address the issue of content authors misusing or intentionally abusing HDR with some kind of auto-limiting algorithm similar to the way the radio 'loudness wars' were addressed. Unfortunately, I suspect it will be difficult, if not impossible, to achieve without also neg…

I believe everything could be solved the same way we solved high dynamic range in audio, with a volume control.

I find it pretty weird that all tvs and most monitors hide the brightness adjustment under piles and piles of menus when it could be right there in the remote alongside the sound volume buttons. Maybe phones could have hardware brightness buttons too, at least something as easy as it is on adjusting brightness in notebooks that have dedicated brightness fn buttons.

Such brightness slider could also control the amount of tonemapping applied to HDR content. High brightness would mean no to low tonemapping and low brightness would use a very agressive tonemapper producing a similar image to the SDR content along it.

Also note that good audio volume attenuation requires proper loudness contour compensation (as you lower the volume you also increase the bass and treble) for things to sound reasonably good and the "tone" sound well balanced. So, adjusting the tonemapping based on the brightness isn't that far off what we do with audio.

Re: What is HDR, anyway?

#329
post #165

Earlier quoted context omitted.

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/

I was old enough to see it as the passing fad it was. Niche, style points first kind of thing for sure. Meta: old enough that getting either a new color not intended, or an additional one visible on screen and having the machine remain able to perform was a big deal.

I missed the MDA/EGA/CGA/Hercules era and jumped right into glorious VGA. Only start options for some DOS-games informed you about that drama in the mid 90s not having any idea what that meant otherwise.

Re: What is HDR, anyway?

#330

Earlier quoted context omitted.

> but your monitor manages 1000-1500 and only in a small window. Owning a display that can do 1300+ nits sustained across a 100% window has been the biggest display upgrade I think I have ever had. It's given me a tolerance for LCD, a technology I've hated since the death of CRTs and turned me away from OLED. There was a time I would have said i'd never own a non OLED display again. But a capable HDR display changed…

Motion resolution? Do you mean the pixel response time? CRTs technically have quite a few artifacts in this area, but as content displayed CRTs tend to be built for CRTs this is less of an issue, and in many case even required. The input is expecting specific distortions and effects from scanlines and phosphor, which a "perfect" display wouldn't exhibit... The aggressive OLED ABL is simply a thermal issue. It can be…

> Motion resolution? Do you mean the pixel response time?

I indeed meant motion resolution, which pixel response time only partially affects. It’s about how clearly a display shows motion, unlike static resolution which only reflects realistically a still image. Even with fast pixels, sample and hold displays blur motion unless framerate and refresh rate is high, or BFI/strobing is used. This blur immediately lowers perceived resolution the moment anything moves on screen.

> The input is expecting specific distortions and effects from scanlines and phosphor, which a "perfect" display wouldn't exhibit...

That's true for many CRT purists, but is not a huge deal for me personally. My focus is motion performance. If LCD/OLED matched CRT motion at the same refresh rate, I’d drop CRT in a heartbeat, slap on a CRT shader, and call it a day. Heresy to many CRT enthusiasts.

Ironically, this is an area in which I feel we are getting CLOSE enough with the new higher refresh OLEDs for non HDR retro content in combination with: https://blurbusters.com/crt-simulation-in-a-gpu-shader-looks... (which hopefully will continue to be improved.)

> The aggressive OLED ABL is simply a thermal issue.

Theoretically, yes and there’s been progress, but it’s still unsolved in practice. If someone shipped an OLED twice as thick and full of fans and heatsinks, I’d buy it tomorrow. But that’s not what the market wants, so obviously it's not what they make.

> It can be mitigated with thermal design in smaller devices, and anything that increases efficiency (be it micro lens arrays, stacked "tandem" panels, quantum dots, alternative emitter technology) will lower the thermal load and increase the max full panel brightness.

Sure, in theory. But so far the improvements (like QD-OLED or MLA) haven’t gone far enough. I already own panels using these. Beyond that, much of the tech isn’t in the display types I care about, or isn’t ready yet. Which is a pity, because the tandem based displays I have seen in usage are really decent.

That said, the latest G5 WOLEDs are the first I’d call acceptable for HDR at high APL, for the preferences I hold with very decent real scene brightness, at least in film. Sadly, I doubt we’ll see comparable performance in PC monitors until many years down the track and monitors are my preference.

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