Ghostbusters 4K UHD (1984)

[dvdmike]

Originally Posted by Rocklandsboy

The horror of it. My eyes bleed every time! Rec 709. Nightmare!

It's like being stabbed in the eyes with aids its nasty horrible stuff, makes me want to puke

[Geoff D]

Originally Posted by FilmFreakosaurus

Some of it could be display issues. Not all models are full 10 bit, rather dithered 8 bit panels, especially the cheaper UHD TV's.

But yes, 12 bit throughout the chain and higher bitrates would be the best.

I don't doubt that some displays are having issues (my own is most likely 8-bit + Hi-FRC which is actually sold as 10-bit by the panel manufacturer FWIW) but according to Dolby's own tests 10-bit just isn't enough when using PQ HDR to avoid banding, especially in the darkest parts of the image because PQ reserves more of the bits for the mid to upper end of the signal (I think).

[Penton-Man]

Originally Posted by FilmFreakosaurus

banding

in regards to HDR/WCG….

[Penton-Man]

Originally Posted by Geoff D

I don't doubt that some displays are having issues (my own is most likely 8-bit + Hi-FRC which is actually sold as 10-bit by the panel manufacturer FWIW) but according to Dolby's own tests 10-bit just isn't enough when using PQ HDR to avoid banding, especially in the darkest parts of the image because PQ reserves more of the bits for the mid to upper end of the signal (I think).

To be precise, in studies performed at Dolby with studio participation, it was determined that in order to avoid any possibility of visible banding for CGI noise-free content, the precision required was 12 bits.

Although, for natural content (e.g. camera acquired) 10 bit precision was deemed acceptable due to camera noise resulting in least significant bit dithering.

At 12 bits precision, each step in code value, whether R, G, or B individually or all three together is below the threshold of visibility for any place on the PQ curve for any content type.

I now return to my favorite channel of the day to watch calcio…err football…err…..https://uk.sports.yahoo.com/blogs/th...123344142.html

[Geoff D]

Just had a quick look at the UHD. Lots more grain, as one would expect, but thankfully it's been compressed with far greater skill than Fox managed with ID4.

As for the rest of it, I'm not convinced. I'm watching in converted SDR, sure, but on every disc I've looked at so far the SDR converted UHD still has a significant amount of extra highlight detail over the regular 1080p Blu-ray - but it's not the case here because the Blu-ray has more highlight detail. If I bump the SDR conversion (usually set at -1) down to something like -5 then I get back the highlight detail that I can see on the Blu, but now the dynamic range is so curtailed that it basically resembles the SDR Blu-ray anyway, grain aside.

I know words like 'fake HDR' are strong ones to throw around - and should best be ignored coming from someone who isn't watching in HDR anyways - but it seems to me as if the HDR grade is only providing a very small amount of extra range and that the originally captured headroom has been spread quite thinly across the bounds of this UHD version.

It certainly suggests that although film is capable of this and that and the other it's not ALWAYS going to yield laboratory-quality results every time, either that or the HDR regrade was carried out very much with the original look in mind. That's no Bad Thing, but it means that the dynamic range is nothing like that of a modern HDR grade so I have to wonder why they'd bother.

[ray0414]

^^^^^ the hdr is most notable in the final battle with gozer. Looks awesome.

[42041]

Originally Posted by Geoff D

Just had a quick look at the UHD. Lots more grain, as one would expect, but thankfully it's been compressed with far greater skill than Fox managed with ID4.

Curious, why is there so much more grain? Seems like UHD wouldn't inherently increase the visibility of grain - possibly the opposite, if 1080p image suffers from aliasing. Is it due to HDR?

[ray0414]

Originally Posted by 42041

Curious, why is there so much more grain? Seems like UHD wouldn't inherently increase the visibility of grain - possibly the opposite, if 1080p image suffers from aliasing. Is it due to HDR?

The movie was filmed with what's called "fast film stock ". This lowers the quality of the negative. rescanning a garbage negative for 4k is going to bring out some extra grain. Hard to blame hdr, because the outdoor scenes look nice, its the Indoor scenes that look like VHS.

[42041]

Originally Posted by ray0414

The movie was filmed with what's called "fast film stock ". This lowers the quality of the negative. rescanning a garbage negative for 4k is going to bring out some extra grain. Hard to blame hdr, because the outdoor scenes look nice, its the Indoor scenes that look like VHS.

No, I know why the movie itself is grainy. I'm just wondering why it would be so much grainier in 2160p than 1080p.

[Geoff D]

Originally Posted by 42041

Curious, why is there so much more grain? Seems like UHD wouldn't inherently increase the visibility of grain - possibly the opposite, if 1080p image suffers from aliasing. Is it due to HDR?

I always thought the higher resolution would resolve more grain, not less, and that's certainly been true of the SDR 4K clips I've seen from the ripped Sony downloads so I don't think HDR itself is the cause. There may have been more "grain management" on the Blu-rays too don't forget, as it's a brave man who thinks we're seeing unmolested grain on most Blu-rays these days (and the difference between the BD and UHD of GBII in respect of grain is MASSIVE).

Anyhoo, I reckon this and GBII are the first SDR-resistant UHDs for the simple reason that they're just not yielding anything like the dynamic range of modern HDR movies. There's a bit extra there I'm sure, but I'm thinking that taking that more limited range and spreading it so thinly across the HDR 'container' means that when it's boiled back down to SDR you're having to throw away information that's otherwise visible on the standard Blu-ray!

Yeah, I can pull that info back on the Panny's SDR converter but then it ends up looking like a duller, grainier version of the regular Blu-ray so I don't know what to do with these two. Keep them until such time as I do get a HDR TV, or sell them for what I paid and nab the two-BD set for peanuts?

[MattPerdue]

Originally Posted by 42041

No, I know why the movie itself is grainy. I'm just wondering why it would be so much grainier in 2160p than 1080p.

Because the image is blown up therefore the grain is blown up too.

[Geoff D]

Well, between these two and ID4 I think my UHD honeymoon is well and truly over. I might have to go back to hating it again.

[reanimator]

Originally Posted by dvdmike

It's like being stabbed in the eyes with aids

wow

[dvdmike]

Originally Posted by 42041

Curious, why is there so much more grain? Seems like UHD wouldn't inherently increase the visibility of grain - possibly the opposite, if 1080p image suffers from aliasing. Is it due to HDR?

Um no, it does resolve more grain that is kinda the point

[42041]

Originally Posted by dvdmike

Um no, it does resolve more grain that is kinda the point

Better resolved grain isn't quite the same as "more" grain though...

I've been doing some photography work on a UHD monitor lately, and a film scan at 4K doesn't seem meaningfully grainier than on my old 1080p panel, beyond the extent to which the image as a whole is more detailed, so I'm kind of surprised that there's "lots" more grain on a UHD movie or that it's more visually objectionable. Doesn't seem to bode well for unmolested transfers on the format

[Pyoko]

One thing I never thought about before with regards to HDR is that the additional contrast can also accentuate the grain, according to this paper.

Q:
How does motion picture film grain, and digital camera sensor noise play a role in HDR production and post-production?

BILL BAGGELAAR: HDR can enhances film grain and digital camera sensor noise, therefore dealing with grain and noise — if you do not want it — becomes more challenging with HDR in post-production. Today we do not have content specifically shot for HDR, so perhaps results would be different if on the outset of a production, HDR was in consideration before they start shooting the first frame. With existing catalog content, noise and grain reduction tools can be used to help manage any noise that gets enhanced or exposed due to the new brightness range. But as I mentioned, the lighting and exposure techniques will need to adapt in order to get the most effective HDR finishing in the future.

Which is a bit worrisome for catalog titles, if they decide to go heavy on the HDR grade and then compensate by reducing grain.

Also a bit surprised at the amount of reports of banding, are these titles banding more than on Blu-ray in general or just in the upper ranges? Even if the bitdepth is spread over a much wider range, in terms of luminance I think half of those bits are allocated to the 0-100 nit range, meaning it's still double what's on 8-bit SDR.

[Pyoko]

Originally Posted by Geoff D

As for the rest of it, I'm not convinced. I'm watching in converted SDR, sure, but on every disc I've looked at so far the SDR converted UHD still has a significant amount of extra highlight detail over the regular 1080p Blu-ray - but it's not the case here because the Blu-ray has more highlight detail. If I bump the SDR conversion (usually set at -1) down to something like -5 then I get back the highlight detail that I can see on the Blu, but now the dynamic range is so curtailed that it basically resembles the SDR Blu-ray anyway, grain aside.

I know words like 'fake HDR' are strong ones to throw around - and should best be ignored coming from someone who isn't watching in HDR anyways - but it seems to me as if the HDR grade is only providing a very small amount of extra range and that the originally captured headroom has been spread quite thinly across the bounds of this UHD version.

It certainly suggests that although film is capable of this and that and the other it's not ALWAYS going to yield laboratory-quality results every time, either that or the HDR regrade was carried out very much with the original look in mind. That's no Bad Thing, but it means that the dynamic range is nothing like that of a modern HDR grade so I have to wonder why they'd bother.

Could also be that other Blu-rays had more aggressive "soft-clipping" of the highlights than Ghostbusters.

And maybe I'm misunderstanding but if the UHD->SDR highlight detail is less than on the BD, all that says to me is that the detail was placed on a brightness level much higher than what could be compressed into the SDR-range, and wouldn't that be the exact opposite of grading with the original look in mind?

[foxborough]

Price reduced to £19.99 on pre-order from amazon.co.uk.

[Geoff D]

Originally Posted by Pyoko

Could also be that other Blu-rays had more aggressive "soft-clipping" of the highlights than Ghostbusters.

And maybe I'm misunderstanding but if the UHD->SDR highlight detail is less than on the BD, all that says to me is that the detail was placed on a brightness level much higher than what could be compressed into the SDR-range, and wouldn't that be the exact opposite of grading with the original look in mind?

Sure, the brightness itself has been mastered much higher but the overall range doesn't appear to contain a huge expansion over the regular Blu-ray. So the image still seems like it's got bright highlights but it's all kinda been shoved into the upper end of the scale, and apart from that concession to the devilry that is HDR it's still very much attuned to the look that was established on the Mi4K Blu-ray, inclusive of colour also. Seriously, when I turn the SDR converter way down on this and GB2 they look almost identical to the Blu-rays. I can't say the same for the other UHDs I've watched so far.

What's funny though is that the GB1 Blu-ray is renowned as this uber-grainy source for 1080p and yet it looks positively sedate next to the UHD. And GB2 is smooth as buttah on Blu-ray (which I always assumed was because of the breakthroughs in taming the grain on faster stock, I think it was shot on 5295) but is noticeably grainier on UHD. Whether that's because the BD sources have been heavily pre-managed or UHD does reveal "more" grain (either thru dat resolution or HDR) is up for debate. Speaking of which:

Originally Posted by 42041

Better resolved grain isn't quite the same as "more" grain though...

I've been doing some photography work on a UHD monitor lately, and a film scan at 4K doesn't seem meaningfully grainier than on my old 1080p panel, beyond the extent to which the image as a whole is more detailed, so I'm kind of surprised that there's "lots" more grain on a UHD movie or that it's more visually objectionable. Doesn't seem to bode well for unmolested transfers on the format

Do you mean still photography? If that's the case then won't that be shot at 8-perf? It's no wonder the grain doesn't look particularly aggressive in that case, I recall looking at the raw 4K grabs of Spartacus (shot Technirama, anamorphic 8-perf) that RAH had and when compared to the 1080p Blu they did indeed resolve finer grain because there's finer grain there to resolve, if you take my meaning.

But 4-perf motion pictures shot on x fast stock (the mind boggles as to what even 125T 5247 looks like in UHD) yield a far chunkier grain structure than large format, so when you're doing those up in 4K the extra resolution is actually resolving more of that underlying coarseness, not less. (But again, we must bear in mind that there's often a certain amount of pre-management for grain on 1080p sources.) At least that's as best as I can figure it, the actual experts will hopefully be along shortly to put me in my place.

[Rocklandsboy]

Originally Posted by Geoff D

Well, between these two and ID4 I think my UHD honeymoon is well and truly over. I might have to go back to hating it again.

Well, I still find myself unable to commit to the format. It's not felt right to me since day 1. It's simply too "good" for most of the material that's presented on it. Catalogue titles will struggle - some more than others - to appeal to the demands of UHD viewers, even moreso than BD did. Yes, of course boosted contrast will emphasise grain! Blu-ray continues to strike the perfect balance, for me, between presenting new/old films to maximum effect.

I'm not prepared to sacrifice the experience of watching 100 movies from the 80s for every one movie from 2016.