View Full Version : Bye Bye good Picture Quality at IMAX


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CINERAMAX
03-03-10, 11:01 AM
I assure you it is not 4 quadrant 4 connection 4k signal, it is a difference/delta method.

When you take a 2k signal and you blow it up to 4k you get part of the signal the added layer fills in the blanks to get full 4k.

GI Joe Sixpack
03-03-10, 11:40 AM
The TI press release's use of "every pixel array in the frame for the brightest picture unlike other technologies in the industry" is comparing to Sony's solution which uses half of Sony's 4K frame. Of course half of 4096x2160 is twice 2048x1080....I don't quite understand what you mean by the last sentence (beyond the obvious math). Sony's solution indeed uses half of the 4K chip to show both images (left and right). But because Sony's bolt-on 3D adapter needs some separation between images, flat (1.85:1) movies actually use less than the standard 1998 x 1080 pixels for each eye (i.e., you have to make them smaller to ensure a gap). Scope 3D images, OTOH, have the same resolution they do on DLP since there is already a gap.

PS. Perhaps you are implying an advantage in showing both left and right images simultaneously instead of time multiplexed? While there may be an advantage, I don't think perceived resolution would be affected. Each eye gets "full" resolution (or nearly full, whatever full means for that format) within the 2K container.

Aidoru
03-03-10, 11:54 AM
Scope 3D images, OTOH, have the same resolution they do on DLP since there is already a gap

I couldn't personally check, but I've been told that Sony 4K machines actually *upscale* Scope 3D material up to something like 2560x1040.

The gap is still there and DCI specs don't allow for scaling (only pixel quadrupling can be used to show 2K files on a 4K machine), but on the upside two fixed lenses can be used and there's more light in Scope compared to Flat.

GI Joe Sixpack
03-03-10, 12:06 PM
So how does that work for Scope without an anamorphic lens? The last 3D D-Cinema presenation I got to see was Monsters Vs Aliens and no ISCO 1.25x anamorphic to be seen. The Barco 2K DLP looked hot though.It is my understanding that anamorphic lenses aren't used in DCI-compliant theaters. As a result, you'll never see any Hollywood movie in such a theater that uses the entire pixel array of either the 2K or 4K projectors. The DCI spec mandates a pixel format of 1998 x 1080 on a 2K display (3996 x 2160 on a 4K display) for 1.85:1 (flat) content, and 2048 x 858 on 2K (4096 x 1716 on 4K) for 'scope (2.39:1). TI's press release is inaccurate (which is why I said "alluding to" in another reply), but then its not like an inaccuracy in a press release is anything new.

GI Joe Sixpack
03-03-10, 12:18 PM
I couldn't personally check, but I've been told that Sony 4K machines actually *upscale* Scope 3D material up to something like 2560x1040.It would be good to get confirmation of that, because it has some interesting implications. Such as requiring a significantly different throw (zoom) ratio for scope 3D content than for flat 3D content when using a constant height screen. (Technically for exact projection you would need two throw/zoom ratios even if they didn't upscale scope, but you could probably get away without it given typical adjustment in masking.) With two lenses that need to be aligned that's bound to make projector setup lotsa fun.

The gap is still there and DCI specs don't allow for scaling (only pixel quadrupling can be used to show 2K files on a 4K machine), but on the upside two fixed lenses can be used and there's more light in Scope compared to Flat.I believe all the Sony lenses are zoom. (AFAIK no digital cinema projection lenses are fixed.) Re scaling, DCI specs do actually allow some scaling under special circumstances even for 2D projection, but apparently the rules are out the window for 3D. There's too much money to made in the short term to enforce minor little rules like that. :D

Aidoru
03-03-10, 05:40 PM
(...) it has some interesting implications. Such as requiring a significantly different throw (zoom) ratio for scope 3D content than for flat 3D content when using a constant height screen (...)

It's the other way around: showing a CIH 1040p frame on a CIH Scope screen negates the very need to have two different zoom ratios.
The final image can be either 1998 or 2560 pixels wide - and side masking can take care of that - but there's no zooming involved, just upscaling from 858p to 1040p in Scope 3D.

I believe all the Sony lenses are zoom (...)

You are right, I meant to say that the 3D Real D XLS assembly (a pic here (http://www.gruponeva.es/userfiles/LKRL_A002_SRX_R220_002%5B1%5D.jpg)) has two *manual* zoom lenses, that are setup once as described above, no matter the aspect ratio. Sony 2D lenses have motorized zoom and multiple presets, as in most DLP 2K projectors.

CAVX
03-03-10, 06:19 PM
It is my understanding that anamorphic lenses aren't used in DCI-compliant theaters.

So is this not a DCI compliant projector?

http://www.avsforum.com/avs-vb/attachment.php?attachmentid=168851&stc=1&d=1267661610

Also check out the way they show SWIII (http://www.christiedigital.com/AMEN/ApplicationStories/StarWarsIII.htm) being projected in letterbox format. I'm sure George was proud of this :rolleyes:

R Johnson
03-03-10, 07:00 PM
So is this not a DCI compliant projector?
My guess is that that's an early model with a 1280x1024 DMD that used two different anamorphic lenses -- one for 1.85 and another for 2.35.

CAVX
03-03-10, 10:50 PM
My guess is that that's an early model with a 1280x1024 DMD that used two different anamorphic lenses -- one for 1.85 and another for 2.35.

Like this?
http://www.avsforum.com/avs-vb/attachment.php?attachmentid=168878&stc=1&d=1267678188
Its a thing of beauty :D

GI Joe Sixpack
03-04-10, 09:02 AM
It's the other way around: showing a CIH 1040p frame on a CIH Scope screen negates the very need to have two different zoom ratios. The final image can be either 1998 or 2560 pixels wide - and side masking can take care of that - but there's no zooming involved, just upscaling from 858p to 1040p in Scope 3D.You're right. But I really meant to say CIW, or specifically NOT_CIH, like we see today in newer theaters with stadium seating. I'm not sure they are truly CIW, but they don't provide all that much adjustment of horizontal masking. They're definitely not CIH and they're alll we have around here now. None of the grand old theaters in town survived. :(

GI Joe Sixpack
03-04-10, 11:08 AM
Like this?
http://www.avsforum.com/avs-vb/attachment.php?attachmentid=168878&stc=1&d=1267678188
Its a thing of beauty :DThat thing sure looks top heavy!

CAVX
03-04-10, 10:49 PM
That thing sure looks top heavy!
Probably why it has to be bolted to the floor :p

Gradius2
04-10-10, 05:10 PM
I wonder when we'll see more 8K projectors, the future is not 4K, but 8K.

So far I have seen only JVC around this area.

johnbr
04-10-10, 09:21 PM
8K they are saying 2017 in the home for it.