[Idea] SDR -> HDR "upconversion"

[deleted user]

Why it's useless:  It's completely artificial on anything more than a few years old.  Films have always been shot on film, and projected on a screen with one bulb of a set brightness.  If you start shining different light levels through a film, sure you can extract more detail, but it is NOT detail anyone ever expected to be on the screen.

And like Zoidberg said, there is also no one standard, so it looks different on every device you watch it on.
Like I said, this is the 3D post-conversion and colorization of black and white all over again.

Great post but I disagree with the final judgment to a degree

Now follows some information I quickly googled and may repeat some of what was already said - don't crucify me if the numbers aren't 100% correct please

If the film was shot on negative (which it likely was) then that negative has the potential to capture about 10 stops of dynamic range (from a quick google) in the linear portion of the film's response curve - if you count in the non-linear portions that can likely be digitally reconstructed to a degree I would argue that you can probably even get 12-14 stops out of a very well preserved low ISO negative film stock (assuming the scene has that kind of variety in the picture)

To compare - the HDR colorspace is cited on Wikipedia as slightly below 18 stops of dynamic range (but most displays apparently only reach around 13!)

Now I totally grant you that nobody ever intended for it to be seen that way - but we also have to acknowledge that they simply didn't have the tech for it to be shown that way - So while it may have been an artistic decision it was one dictated by the available tech

Rescanning that negative with the full available dynamic range and mapping that into the HDR colorspace is absolutely not comparable with 2D-to-3D conversion and BW colorization in my opinion because the information is actually there - it was just never used - whereas with the two techniques you mentioned you more or less skillfully "invent" and interpolate that additional information

It's imo more comparable to creating a 4K (or more?) remaster from good negatives - this detail was also never seen in cinemas (film prints are notoriously unsharp) but it's nevertheless real detail that is now rediscovered

Granted - they could (and likely do) do shitty restaurations where they do in fact stretch a low dynamic range image (like an evenly lit scene shot in a studio) into the wider gamut to create artificial contrast and that would look bad - but if done conscientiously the HDR technology has the potential to create very natural looking and immersive scenes in a way that was never possible before - even from old film stock!

No - this would not be authentic to the original movie experience - but it could be a kind of remaster and reinvention that in my opinion could actually be a worthwhile alternative to watching the movie - not as a replacement but as a --- "remix"

And of course it's also possible to do a scan of the interpositives (is that the right term?) and leave them at their natural dynamic range and portray that in the (not fully filled up) HDR colorspace - something that wasn't really possible before either

As for calibration I'm sure a solution will eventually surface for the consumer market - and the people who do the color grading I think do have calibrated devices (I could be wrong tho!)

[CSchmidlapp]

Everything you have mentioned Tom would happen because of the higher bit depth and wider color gamut.
The scanning of film elements with several passes to retain as much detail as possible is also something that has always been done, but in order to deliver it to us, huge compromises have had to be made in order to 'squash' it into the delivery mediums available.

The 'HDR' we're talking about seems to be nothing more than a process to deliver a higher bit depth and wider colour range on variaties of sub par equipment to 'mimic' what it would be like viewing on a panel that could produce all the variables e.g 10bit BT 2020.

I am no expert on it though and thought maybe this version of HDR (HDR10, Dolby Vision ect) were much like what the lossless audio codecs, where there was a core (more for compatibility purposes) and additional information to decode it back to its lossless form.

[spoRv]

The 'HDR' we're talking about seems to be nothing more than a process to deliver a higher bit depth and wider colour range on variaties of sub par equipment to 'mimic' what it would be like viewing on a panel that could produce all the variables e.g 10bit BT 2020.

Interesting point of view... we'll see in the future it it's true.
Maybe it's a bit like the curved screen - everybody wanted one, but after few... months? anybody realized how much useless they were.

[deleted user]

Agreed. Not sure about sub par equipment as I haven't researched it enough. Maybe I should.

Dolby Vision is - from what I understand - a bit comparable to that concept you mention - it has two video tracks - the second of which helps restore the higher bit depth as an individual video track on an UHD Blu Ray is limited to 10 bit apparently. But lossless it definitely isn't. Still all h265.

Edit @ spoRv - I never understood why anyone would want a curved screen lol

[spoRv]

Edit @ spoRv - I never understood why anyone would want a curved screen lol

I can think of it ONLY if you have one of those beautiful strange houses seen on the magazine covers, one with curved wall with the same EXACT curvature of one of such curved screen!

[CSchmidlapp]

When I say 'sub par' Im referring to anything below the master format

Yes it was the Dolby Vision talk that swayed my mind on the 'HDR' Home Video process is perhaps something more than a gimmick.

[CSchmidlapp]

To address your OP spoRv.

I see converting to 10bit and then filtering / color grading and finishing at that bit depth for personal projects as a plus. Like already pointed out the reduction in gradiants would justify this alone. Extending color range would come hand in hand with this

[OogieBoogie]

it's like painting, the more color gradients you use, the better the shading, which to our eyes is the same as increased detail as you are effectively highlighting what you want to be seen. I personally think usage of a wider color gamut within fanres makes sense, not with everything, but alot of films could benefit from it, but I repeat, I don't think 4K the resolution is worth it, the difference is too small for our eyes to notice without going to huge viewing sizes. The combination of 1080p with HDR/10 bit/wider color gamut makes more sense.
If you wanted you could do a test, say something like Lone Survivor which was filmed in high contrast with a lot of greens in the image. If you applied a wider color gamut to the bd disc, I bet you could get really close to the UHD image and my gut instinct is that it would actually look better.
Don't know if your merging program can handle UHD yet, but that would be a very interesting project type if it does, taking their colorbase and applying it to the best bd version or alternative hd source.

[spoRv]

Don't know if your merging program can handle UHD yet, but that would be a very interesting project type if it does, taking their colorbase and applying it to the best bd version or alternative hd source.

Well, the great software is random.next's creation! Sure it would handle UHD, and you know what? I was thinking almost the same, but why do all this work? Just downscale luma, and leave chroma untouched; but you will need to save it in RGB or YV4:4:4

[spoRv]

Found this interesting article - hope will be useful: http://www.lightillusion.com/uhdtv.html