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#21 | Link | |
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![]() Honestly, though, most of the content we watch is not through recompression. I wonder, in reference to film, does 35 mm resolve to a maximum of 4K, and 65/70 mm to a maximum of 8K? Or can they be scanned at even higher resolutions, and it's just a matter of time and cost? Last edited by GeoffreyA; 14th January 2025 at 19:53. |
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#22 | Link |
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Required/necessary resolution will differ quite a bit per stock.
You may consider film stock's spatial properties as silver grain "blooming" with desired (sensitivity) gain. Blooming is not a desirable parameter here because I suggest the term "blooming" to describe "growing bigger grain while developing more sensitive emuslsions/solutions breeeding more black silver per photons even at longer wavelengths but sacrificing spatial resolution" If the decision was made to have maxed resolution you may assume positive stock with low sensitivity. This delivers max b/w resolution, worth 4k from 35mm, and 8k from 65mm, and I am talking b/w stock here. so this would apply to colour formats that are based on b/w stock as well (3-stripe) The desire to shoot with "available light", well "lets spare the expensive and artificial professional lighting" led to emulsions with bigger grain, worth 4K for 35mm at its best, 2K if judged by cost-conscious professionals, and some ~800 lines IIRC if BBC and the then mainstream footage was to be judged. And this may well apply to colour negative stock used for budget to midrange films from 1980 on. BTW, you may even run FFT on your footage and see what frequencies it contains and which sampling rates it might need to be represented properly. Grain will eat most of that spatial information, not necessarily picture detail. But: later algos will try to guess from there, so it might be beneficial later. Tests (and my findings) have shown that aside from pure Nyquist (you know just enough if you sample twice ;-))... if luxury allows: Spend a bit more on sampling and maybe you gain later, and this finally would confirm your assumptions.
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#24 | Link |
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A nice reading:
https://cool.culturalheritage.org/vi...eption_v24.pdf
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#25 | Link | |
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I was surprised to learn that Kodak is actually seeing increases in film use in the last couple of years, more film schools buying it, and are making long-term capital investments in film stock production. |
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#26 | Link | |
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But if film use is increasing, that's good news, of which I'm glad. EDIT: As fate would have it, I posted this comment on Lynch, and a short while later read on the news that he died today. This makes me sad because he was, arguably, my favourite director. Alas, there won't be a Twin Peaks season four from his hand, nor more of his strange, surreal works. Rest in peace, David Lynch. Last edited by GeoffreyA; 16th January 2025 at 22:25. |
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#27 | Link | |
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As long as grain is either small enough to not have much visual impact or coarse enough that it isn't just spatially random (as in particles have shapes), it's not too bad . But grain that's close to pixel level both makes compression very challenging at native resolutions and just vanishes at lower resolution due to the low-pass filtering of downscaling. That's a creative intent that it's simply not possible to deliver in pristine quality over IP without film grain simulation. Last edited by benwaggoner; 17th January 2025 at 19:55. |
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#28 | Link |
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Alright, alright, hear me out.
The beauty of HLG is that it allows anyone to shoot in HDR anytime without any further processing required. Strictly speaking, up until this point we've been talking about cinema productions where you have a very controlled environment, you shoot log in a totally logarithmic curve (Slog3, Clog3, LogC, ZLog) at high bit depth and then you grade the raw footage to create the final PQ version. That's all fun and games, but not the life of an average user. With HLG you could be in the middle of a forest, by the lake, having a picnic during the weekend, and you may wanna record a video for some personal memories. You can pick up your camera and you don't have to shoot BT709 SDR. You have the benefit of BT.2020 for Wide Color Gamut and the ability to record up to 1000 nits if your sensor has enough stops. Sure, you're not gonna have details in the blacks (which are mostly noise anyway in non professional cameras and difficult / unpredictable environments) but at least you have HDR. Modern cameras nowadays have way more than 6 stops (i.e what was needed to record natively in BT709 SDR 100 nits), so recording in BT709 feels like a total waste. And sure, you don't need a Sony FX6 to shoot log, so one could say that an enthusiast private consumer who has a Sony A7III for private use could very well shoot Slog3 and then create the final PQ version out of it, but realistically aside from me, you and a bunch of people on Doom9, who's ever gonna do that for private free time stuff? I made that very same mistake myself and I still have a bunch of Slog3 footage sitting in my HDD waiting to be re-encoded and it probably never will (I've been procrastinating this for years). Going back to the "more than 6 stops" argument and BT709 SDR, obviously modern camera manufacturers are well aware of their sensors having way more than 6 stops, so they also allow you to record in a "smarter" way than just plain old BT709. Sony cameras for instance have things like "Cinetone" which is still BT709 SDR 100 nits, but it's converted internally by the camera with soft highlights rollback to give a "better" feeling and preserve a bit more details. Anyway, why would anyone go through all these compromises when he could just shoot BT2020 HLG? With HLG you can shoot HDR in any condition, you don't need to grade it again (unless you want to) and you can play it back on your TV, on your phone, on your PC... anywhere! It's ready to use, easy to record and it allows the world to finally move away from using BT709 SDR by default. HLG isn't evil, it works extremely well in practice and I'm sure it's gonna be here to stay. ![]() p.s I've been shooting all my personal video for personal private memories in BT2020 HLG for years now. Last edited by FranceBB; 18th January 2025 at 20:41. |
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#29 | Link |
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HLG makes sense for consumer content production, as it can be played as-is and captures more dynamic range than 709. A huge deal to lots of people, even if not to me personally (although I do shoot some HLG + Dolby metadata on my iPhone).
The professional content I am concerned with isn't shot in any consumer color volume or EOTF. It's going to be film, a RAW (cinematic) or a Log (live) variant of some sort. Nothing is going to be delivered in the camera format, and creating separate 709 and PQ versions provides more control and quality than HLG would have by itself. |
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#30 | Link | |
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I agree that film grain is a curse to encoders and the chief problem when it comes to delivering respectable quality at lower bitrates. It's no wonder that modern codecs and encoders have spent so much effort on denoising and film grain synthesis. |
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#31 | Link | |
Lost my old account :(
Join Date: Jul 2017
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And tbh, I never liked Nolans format-fixation, I find the constant change of cameras and formats in his movies are more distracting than the value of the 70mm sections brings. I also dont understand, if he now likes the taller imax format, why the 35mm stuff isnt non-anomorphic open matte, so he can present the whole movie in a taller format. Last edited by excellentswordfight; 27th January 2025 at 13:39. |
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#32 | Link | |
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Regarding Dune, I think it doesn't look that great, and yes, I know I'm in a minority to speak such sacrilege. It's framed beautifully, but I've never been happy with the texture and softness of the picture; and let's not even talk about the frequent CGI, marring the whole effect. As a movie, though, I am fond of it. And it compresses well! With regard to Nolan, I find the switching of aspect ratio is done, on the whole, "transparently" and isn't that noticeable. I think it adds a certain effect, a theatrical feeling or charm. These days, he is shooting his whole movies in both 65 mm and IMAX. Interstellar was the last with 35-mm footage. Peele's Nope is another recent example that used a combination of 65 mm and IMAX to great effect. |
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#33 | Link |
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I have a question, are the silver grains (or whatever grains in color films) the smallest recording unit of a film? In other words, will a grain contain details within?
P.S. Thanks for the recommendation of Nope, it looks great and the story is thrilling. I came up with this question when watching it, because I think the details are finer than the "film grain noises". Last edited by Z2697; 2nd February 2025 at 07:14. |
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#34 | Link |
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The silver particles are the smallest parts. Hi-Res Film 0,05µm..X-ray 2µm, these will agglomerate to clumps, forming the ~10 times larger grain.
Color: dye clouds are the remaining parts here, larger size, differing wide with film speed
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"To bypass shortcuts and find suffering...is called QUALity" (Die toten Augen von Friedrichshain) "Data reduction ? Yep, Sir. We're that issue working on. Synce invntoin uf lingöage..." Last edited by Emulgator; 3rd February 2025 at 00:57. |
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#35 | Link | |
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compression, encoding, hevc, marvel, staxrip |
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