criterionforum.org

This was posted by another user on r/criterion, but I think that it is useful information regardless:

There have been some releases where the HDR10 encode is reportedly of lesser quality than the Dolby Vision encode on the same disc, though, such as the StudioCanal UHD of Le Cercle Rouge.

Now that you mention it, I remember the It's A Wonderful Life 4K disc reportedly having the same issue. So it may be worth looking into. (But I last was on the hunt in 2017 - it's probably harder now to find a setup NOT capable of Dolby Vision.)

It doesn't look like there are any projectors capable of Dolby Vision.

I’m currently building a new home theater room with projector and large screen and have been searching high and wide and unfortunately have not come across a single projector that offers Dolby Vision, only HDR and HDR-10+. While I have not bought one yet and will wait another 6 months at least, I haven’t come across any announcements that one is planned.

What was the biggest push for Criterion? My guess is Arrow's success with 4K releases.

My guess is perhaps a drop in the price of UHD replication.

That… makes more sense.

denti alligator wrote: Mon Aug 16, 2021 11:19 pm I don't fully understand HDR. Is Dolby Vision a "kind" of HDR. Will Criterion only be using that kind? There's HDR10, too, right? Difference? Is this something that requires both the right player and display or just player?

soundchaser wrote: Mon Aug 16, 2021 11:28 pm They're basically the way the dynamic range is encoded - HDR10 is considered the standard, and Dolby Vision is a more recent and more involved development. (There's also HDR10+, but I don't think many - if any - discs are using it.) I really haven't noticed a difference between the two, personally speaking. There are all sorts of technical comparisons with brightness, banding, etc. that are really beyond me. Regardless: you'd need both a player and a TV capable of handling Dolby Vision, which I think is most now minus Samsung.

Actually it's the other way round. Dolby Vision was developed first, before any other HDR format, and is the standard that the others are derived from. After Dolby developed PQ (the transfer function that replaces gamma to allow HDR imaging), they came up with Dolby Vision as the carrier format to ensure the image would be tone mapped properly to the receiving display. This is what the dynamic metadata is, that essentially tells the TV how to display each scene or frame based on its own capabilities, which is needed for HDR as TVs have different brightness abilities, none of which can reach as high as the PQ transfer function allows (10,000 nits).

In addition to its dynamic metadata it also allows 12 bit colour depth, along with the Rec.2020 colour gamut. But, Dolby charges for the use of the DV format and so HDR10 was developed as a free open standard for those who did not wish to use DV. It drops the 12 bit colour depth, offering only 10 bit (hence the name, HDR10), along with dropping the dynamic metadata, replacing it with static metadata. The difference being that instead of tone mapping on a scene by scene basis, static metadata can only tell the TV what is the highest level of brightness the specific source goes to, and the TV will decide how best to deal with that (each manufacturer has a different approach). This can and does lead to HDR images being presented improperly, especially the more the TV lacks a decent brightness level. Meaning Dolby Vision is much more use to those with dimmer sets, such as most standard OLEDs.

senseabove wrote: Mon Aug 16, 2021 11:47 pm There have been some releases where the HDR10 encode is reportedly of lesser quality than the Dolby Vision encode on the same disc, though, such as the StudioCanal UHD of Le Cercle Rouge.

Yes, this is a result of HDR10 dropping the enhancement layer that allows 12 bit colour depth on DV. Dolby Vison isn't naturally better encoded than HDR10, both can be encoded as well as the other, but many discs from StudioCanal show extreme compression issues on the HDR10 layer because of the way they author their discs (the theory being they encode the 12-bit DV version properly, and then run off an automated version for HDR10, which gets mangled because so much of the needed data is lost in the dropping of the enhancement layer). This really only affects StudioCanal discs though, there are many DV discs where the HDR10 layer is fine (indeed, many DV discs don't use the 12 bit enhancement layer anyway, instead being 10-bit themselves).

vsski wrote: Tue Aug 17, 2021 1:49 am I’m currently building a new home theater room with projector and large screen and have been searching high and wide and unfortunately have not come across a single projector that offers Dolby Vision, only HDR and HDR-10+. While I have not bought one yet and will wait another 6 months at least, I haven’t come across any announcements that one is planned.

Yes unfortunately no projector offers Dolby Vision. This is because dynamic metadata only works if the brightness capabilities of the display are known. Whilst you can know the maximum brightness of a projector, you can't know what that maximum brightness is in a real world setting, because the size of the projected image, the type of projection screen, and the conditions of the viewing environment, all affect it. For this reason Dolby have essentially made DV a TV exclusive format. You can invest in a device like madVR which is designed to offer dynamic tone mapping for projectors, by processing the signal from your player before it reaches the display. But it still means you'd be stuck with the terrible HDR10 compression layers on StudioCanal discs if using a projector, unfortunately.

Boosmahn wrote: Tue Aug 17, 2021 2:30 am What was the biggest push for Criterion? My guess is Arrow's success with 4K releases.

I personally hope it was a result of Elephant Man and Crash underperforming in sales, along with vocal customers telling them they'd be importing the region free UHD versions available elsewhere instead. Oh and Kino stealing Silence of the Lambs from under their nose, along with some other as yet unannounced spine numbers. The fact that Lee Kline only recently showed on his podcast that he is no fan of HDR or the UHD format gives the impression Criterion have in a sense had their hand forced here.

Thank you very much Eddie - as always very insightful and easy to follow for a technical layman as myself. This also tells me that there is no point waiting for a DV projector, as it will not appear and to simply optimize my setup and stay away from Studio Canal UHDs - the latter is easy as I don’t own a single one of their discs in any format, even though I know some folks here had great comments about some of their BDs.

EddieLarkin wrote: Tue Aug 17, 2021 8:46 am Yes, this is a result of HDR10 dropping the enhancement layer that allows 12 bit colour depth on DV. Dolby Vison isn't naturally better encoded than HDR10, both can be encoded as well as the other, but many discs from StudioCanal show extreme compression issues on the HDR10 layer because of the way they author their discs (the theory being they encode the 12-bit DV version properly, and then run off an automated version for HDR10, which gets mangled because so much of the needed data is lost in the dropping of the enhancement layer). This really only affects StudioCanal discs though, there are many DV discs where the HDR10 layer is fine (indeed, many DV discs don't use the 12 bit enhancement layer anyway, instead being 10-bit themselves).

EddieLarkin, thanks so much for your clear and in-depth explanations of the format. I've been curious about something you can probably answer. Is there a massive disc space difference between a DV and HDR10 layer if a release features both? To clarify, is it akin to when there are two cuts of a film on a standard blu ray which does not use seamless branching and each one is, say, 22gb a piece, or is the difference just a small metadata file therefore causing no disc space issues?

Grand Wazoo wrote: Tue Aug 17, 2021 12:28 pm EddieLarkin, thanks so much for your clear and in-depth explanations of the format. I've been curious about something you can probably answer. Is there a massive disc space difference between a DV and HDR10 layer if a release features both? To clarify, is it akin to when there are two cuts of a film on a standard blu ray which does not use seamless branching and each one is, say, 22gb a piece, or is the difference just a small metadata file therefore causing no disc space issues?

Any disc that offers DV has to have a HDR10 layer, but no there are no disc space concerns, because as you say it is just metadata. If the DV layer is MEL (minimum enhancement layer, that is, 10 bit only just like the HDR10 layer), then the extra space needed to fit it on the disc is completely insignificant (like, a fraction of a MB), and even if it's FEL (full enhancement layer, i.e. full 12 bit DV), which does carry some actually hard data, it's still only a few MB of disc space.

The Blu-ray.com forums maintain a complete list of all DV titles that use FEL, and which use MEL.

Thank you for this thorough technical runthrough, Eddie. I recently bought a BenQ HT3550, and I must say that I got what I expected: Not exactly a breathtaking rendering of HDR10. However, I am not one of those who have turned HDR off on my player and let it decode to Rec.709. I still think that even on a projector HDR adds a feeling of, for lack of better words, depth and smoothness to the image. Also the upgrade in resolution and of course the better compression clearly, to my eye, gives better image stability and clarity. The colours are also better rendered, even if not as great as they could be. What I am not impressed with is the PJ's rendering of film grain in HDR. It is almost invisible to the point of looking DNR'ed. However, I still really love the 1080p image of this projector. The image is much superior to my previous projector, and it has given my blu-ray collection a new life and a very very filmic rendering of grain, so I don't think I would outright advise against buying a 4K PJ. Just don't do it for supreme rendering of HDR/UHD's.

EddieLarkin wrote: Tue Aug 17, 2021 12:38 pm Any disc that offers DV has to have a HDR10 layer,

Does this mean that with a projector capable of HDR10 I'll at least get some of the HDR benefit of the new Criterion UHD releases?

denti alligator wrote: Tue Aug 17, 2021 2:03 pm

EddieLarkin wrote: Tue Aug 17, 2021 12:38 pm Any disc that offers DV has to have a HDR10 layer,

Does this mean that with a projector capable of HDR10 I'll at least get some of the HDR benefit of the new Criterion UHD releases?

Yes, and you may even get all of the benefit. If some of the Criterion titles use MEL DV instead of FEL DV, and they are of a fairly restrained brightness level, then there will be no difference between the HDR10 and DV layer anyway. Oftentimes DV is included on a UHD as a box-ticking exercise to encourage purchasing, rather than any actual practical reason.

jegharfangetmigenmyg wrote: Tue Aug 17, 2021 1:49 pmWhat I am not impressed with is the PJ's rendering of film grain in HDR. It is almost invisible to the point of looking DNR'ed. However, I still really love the 1080p image of this projector. The image is much superior to my previous projector, and it has given my blu-ray collection a new life and a very very filmic rendering of grain, so I don't think I would outright advise against buying a 4K PJ. Just don't do it for supreme rendering of HDR/UHD's.

That's strange to hear because if anything, HDR should make grain more visible, not less. Are you sure there isn't some sort of heavy noise reduction option that is default on in HDR mode?

EddieLarkin wrote: Tue Aug 17, 2021 2:15 pm

jegharfangetmigenmyg wrote: Tue Aug 17, 2021 1:49 pmWhat I am not impressed with is the PJ's rendering of film grain in HDR. It is almost invisible to the point of looking DNR'ed. However, I still really love the 1080p image of this projector. The image is much superior to my previous projector, and it has given my blu-ray collection a new life and a very very filmic rendering of grain, so I don't think I would outright advise against buying a 4K PJ. Just don't do it for supreme rendering of HDR/UHD's.

That's strange to hear because if anything, HDR should make grain more visible, not less. Are you sure there isn't some sort of heavy noise reduction option that is default on in HDR mode?

Could of course also be because the shot on film UHD-titles that I have tested (The Kubricks, The Hitchcocks and Apocalypse Now, etc.) come from very fine grain film sources, I don't know. I've been comparing these to Criterion's new release of Mirror which in comparison has very heavy grain. It would be interesting to see a film shot on 16mm on UHD. I'm not aware of any. The German release of Texas Chain Saw Massacre is an upscale AFAIK.

Thanks for the clear, detailed explanations, EddieLarkin!

senseabove wrote: Tue Aug 17, 2021 4:05 pm Thanks for the clear, detailed explanations, EddieLarkin!

Seconded! (Or seventhed, at this point.)

A couple 16mm UHDs: the original The Evil Dead, Mother!, and the original Maniac

HDR has got to be the most poorly understood element of home video viewing ever, so I'm happy to help with any questions (to the best of my ability anyway).

dwk wrote: Tue Aug 17, 2021 4:23 pm A couple 16mm UHDs: the original The Evil Dead, Mother!, and the original Maniac

The Techniscope films that Blue Underground released on UHD are also super grainy (in a lovely lush way): Zombie, The New York Ripper, House by the Cemetery. Indeed all of their titles are, they seem to be very purist when it comes to grain reproduction, much like Arrow when they perform their own restorations. I don't know if a different authoring house than usual did The New York Ripper though as that's one of the few non-SC UHDs that has a poorly encoded HDR10 layer alongside a superior DV layer, and also has a colour gamut conversion error (correctable on some TVs in HDR10, but not DV!).

EddieLarkin wrote: Tue Aug 17, 2021 4:55 pm HDR has got to be the most poorly understood element of home video viewing ever, so I'm happy to help with any questions (to the best of my ability anyway).

I don't know if this is too much extra work, but in cases where forum posters elsewhere like yourself become an expert source on a particular topic, they ended up creating a FAQ. Usually they already had blogs or their own website so it fit in with their usual workload, and it usually evolved out of a similar thing where they ended up answering so many questions (which they were happy to do ), it just made sense for them to create one.

Re: projectors lacking Dolby Vision due to uncontrollable variation in brightness, I assume that isn't an issue in theatrical 4k projection? Or is it irrelevant, because HDR10/DV are home video standards and theatrical DCPs have their own standards?

senseabove wrote: Tue Aug 17, 2021 5:11 pm Re: projectors lacking Dolby Vision due to uncontrollable variation in brightness, I assume that isn't an issue in theatrical 4k projection? Or is it irrelevant, because HDR10/DV are home video standards and theatrical DCPs have their own standards?

Yeah, PQ, and thus DV/HDR10/HDR10+ are primarily home video standards. There is Dolby Cinema, which I assume still uses PQ and Dolby Vision, but I know its peak white level is only 108 nits (normal theatrical projection is 50 nits). Of course the larger the screen, the more effect these smaller numbers have. But yes, ultimately, theatrical and home video require two separate gradings entirely. Though in theory if you're a big fan of HDR imaging, you're better served with a top of the line TV than you would be in the cinema.

hearthesilence wrote: Tue Aug 17, 2021 5:00 pm I don't know if this is too much extra work, but in cases where forum posters elsewhere like yourself become an expert source on a particular topic, they ended up creating a FAQ. Usually they already had blogs or their own website so it fit in with their usual workload, and it usually evolved out of a similar thing where they ended up answering so many questions (which they were happy to do ), it just made sense for them to create one.

I'm a somewhat well read layman and I don't think I'd really be qualified, I'm sure someone like David M could make (hopefully minor) corrections to everything I've posted here, for instance. Geoff D is a fantastic resource over at Blu-ray.com, and his reviews are more valuable for information on releases and general HDR tech talk than anywhere else on the web. They are linked via this FAQ.

Hi Eddie, you explanation is crystal clear and massively helpful. I do have an additional question that has huanted me for a long time. When people talk about a film getting graded in HDR, what are the colorists doing differently from when the film is done in SDR? I gather that in SDR, you are still able to assign brightness, contrast, and specific colors to each scene (or each frame if it's desired to do so) and fine tune the image to your heart's content. So what exactly does HDR bring to the table at the grading stage? Does grading on a HDR-capable display make people see each scanned image differently and assign another set of brightness, contrast and color values?

I guess what confuses me is the fact that HDR and WCG often come hand in hand and it's hard for the technically less informed to really discern what is the benefit brought by WCG and what exactly is the result of HDR replacing SDR.

FrauBlucher wrote:City Lights is listed as 4k remaster. I was wondering for technical reasons, like frame rate, or that's no longer an issue

City Lights isn’t a silent film, so there’s no frame rate issue.