Film-Tech Forum ARCHIVE: Sony 3D questions

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Posted by Scott Norwood (Member # 30) on 12-28-2011, 08:36 AM:

I had my first experience with a Sony 3D presentation last night. Woo-hoo.

Some questions:

- My understanding is that the Sony 3D system is essentially the same thing as under/over 35mm 3D. The projector itself had some sort of mirror box attachment to it and there were two images being projected through the port glass. Yet the theatre had Real-D signs all over and the glasses themselves say Real-D on them. What is Real-D providing in this case? Why would a Z-screen (or some other Real-D technology) be needed here? The movie screen itself had a silver surface.

- The theatre showed television commercials before the screening. These were shown in 2D through both halves of the mirror box, but were poorly converged on the screen. The picture was hard to watch (with or without glasses) and looked quite unsharp. Is there any reason why the two images cannot be converged properly? Or was this just poor maintenance on the part of the theatre? The 3D picture looked OK, however (presumably because convergence is less critical).

- This was also my first experience with the Sony 4K system. It looks noticeably different from DLP. It does not have the nitrate-like eye-popping "whites" that DLP has, but it also does not have visible space between the pixels. The picture quality overall looked to be less sharp than 2k DLP, but that may be partially due to the convergence issue noted above. Until I see a 2D feature projected with this system, I can't say which I prefer. The Sony picture was dim, but that is true of pretty much every 3D setup. Are my observations typical of what others have seen?

edit: I should also add here that the fake 3D in the Titanic trailer looked surprisingly good. It was not perfect, but it looked better than it had any right to look. I generally think that the idea of doing fake-3D reissues of 2D features is silly, and I have no interest in seeing this one, but I was really shocked at how good it looked for a 3D conversion.

Posted by Alan Gouger (Member # 543) on 12-28-2011, 09:28 AM:

Sony uses RealD.

quote: Scott Norwood
The projector itself had some sort of mirror box attachment to it and there were two images being projected through the port glass

The lens provides the polarization filters for each channel. Sony does not use triple flash ( resulting in one image ) two images are projected at the same time and the lens provides the polarization filters for each ch. A silver screen is needed:(

quote: Scott Norwood
It looks noticeably different from DLP. It does not have the nitrate-like eye-popping "whites" that DLP has, but it also does not have visible space between the pixels. The picture quality overall looked to be less sharp than 2k DLP, but that may be partially due to the convergence issue noted above.

You have a good eye:) DLP verses Lcos. DLP is known for high ansi contrast pop but has the weaker on/off contrast of both technologies. This is reversed with Lcos. Chose your poison.
DLP is also the sharper of the two.
Consumer machines are closing the gap between the two. Most are displayed in a bat cave where the advancement in contrast can be appreciated.

It is my understanding when using the 3D lens the projector is no longer running in 4k mode but 2k mode to provide the full pixel resolution for two 2k images continually. You can leave the lens on to display a 2D movie but it will be displayed at 2k.

Posted by John Thomas (Member # 6509) on 12-28-2011, 11:40 AM:

The Sony projects two 2K images simultaneously inside of its one 4K frame. The RealD XL box serves to converge these two images onto the screen as well as to polarize them. This is an advantage over the z-screen setup because it is a constant 3D image, as opposed to flickering back and forth between the two eyes.

As long as that RealD XL box is on, anything you see on screen will be 2K.

Many theatres (most in my chain) never adjust convergence, so the issue you noted is common. Mine need a minor convergence adjustment weekly, even when nobody has touched them.

Posted by Keegan O'Brien (Member # 6539) on 12-28-2011, 12:39 PM:

I can't stand 3D on any projector, much less the Sony's. 21K lumens + Polarized filter + 3D sunglasses + silver screen all on a large screen. A nightmare for image quality because of the lack of brightness.

However, when I saw Moneyball on a Sony projector with a 4K server, and a 4K DCP... it was the best looking image I've seen outside of IMAX. I can't imagine what 4K DLP must look like.

Posted by Scott Norwood (Member # 30) on 12-28-2011, 01:18 PM:

So Real-D is just providing the mirror box for the Sonys? Why doesn't the theatre just buy the mirror box outright? Or is Real-D the only supplier for it?

Posted by Paul Mayer (Member # 355) on 12-28-2011, 03:20 PM:

The RealD XLS (XL for the Sony) is not just a "mirror box" - it also has two separate lenses with a swing out polarizer for each. The two lenses share a common optics box and the entire unit uses a single mount to mate to the projector.

Due to the mechanical nature of aligning the two lenses (focus, zoom, and vertical position for each, plus image rotation and lock for each image on the optics box) the precise overlay of the two images can take some effort to get it just right, but once you learn its quirks (especially compensating for the image shifts that occur as you tighten the zoom and focus lock screws on each lens) you can achieve a good overlay in a few minutes during install.

The alignment adjustments are all exposed, and can get bumped around, especially if a given theater is moving the polarizers out of the way for 2D shows. If a theater is alternating 2D and 3D shows on a Sony 3D screen, that can lead to a lot of manipulating of the polarizers. Since both lenses are used even for 2D, if the overlay becomes sloppy, you will get a soft looking image. In the case of looking at 2D TV spots with a sloppy overlay, I can see where it could look really soft.

Posted by Monte L Fullmer (Member # 2797) on 12-28-2011, 03:52 PM:

And with "Moneyball" being in flat, that file was barely using one half of the LCoS chip in the Sony when it's in the twin lens mode.

..and not even in HD quality due to the imager chip being split in half, thus you have just 858 x 2048 resolution out of each eye.

And you shove a 1.85:1 image on that one half of a chip you're 858 pixels high by 1587 pixels wide.

HD is 1080 pixels high.

Sony servers (called a media block) are built in with the projector,thus the whole this is built as a one piece unit.

I'm sure that "Moneyball" looked great on that screen, especially if it was a silver screen-tons of contrast is the results. Also, you were prob sitting in the back third of the auditorium. Now, if you took a 35mm print and played the digital versions side by side to each other and get down in front about 20 feet from the screen, I bet the film will be sharper than the digital due to the low pixel rate.

This is the big reason for 4K so those sitting down in front can have the same sharp picture if they sit in the back.

Plus, the 2k file is scaled up to fill the 4k chip in single lens mode.

So much for SONY 4K marketing jazz...when the majority of the content out there is still in 2K.

Sadly, all of this 'digital wars' has to come from the industry's long time nemesis: being the television. Now, home comsumer products seemed to have set the "tone" for how entertainment is to be presented due to the digital medium. Yet, those home ET owners don't realize that what they are seeing is really the same as on the big screen in pixel terms. Thus, when they are watching a 'scope movie on their big screens at home, it's still not HD quality since the height of that image still fall short of HD requirements of 1080 pixels high.

Posted by Keegan O'Brien (Member # 6539) on 12-28-2011, 07:26 PM:

Monte, I didn't see Moneyball in a 3D capable auditorium. It wasn't using dual lenses, and Moneyball has a 4K master. It was the first movie I saw in legitimate 4K.

Posted by Alan Gouger (Member # 543) on 12-28-2011, 10:29 PM:

Curious, is that 3D lens from realD sold to the cinema or rented. If rented is the amount based on ticket sales or is it a flat rate. Can anyone say how much. Thx.

Posted by Dominic Espinosa (Member # 2122) on 01-06-2012, 04:19 PM:

quote: John Thomas
Mine need a minor convergence adjustment weekly, even when nobody has touched them.

Then the lock screws aren't tight enough.

Once locked down you have to be kind of rough with it to mess up the alignment.

The lens assembly is leased and paid for via the surcharge.

Posted by Dave Macaulay (Member # 813) on 01-07-2012, 09:01 AM:

Real-D in North America (Canada & USA, not sure about the rest) signs a licensing agreement with the cinema ownership. The contract has conditions like having only Real-D 3D in the building for a multi-year term. You then pay a per-ticket 3D charge directly to Real-D. They provide all the 3D equipment at no additional cost (the projector optical device and the glasses). The total cost to the owner is the per-3D-ticket licensing fee and the shipping cost to send used glasses back to Real-D for refurbishment.
Having no upfront pricetag has worked well for Real-D, they have a commanding lead in market share in the USA and Canada.

Posted by Carsten Kurz (Member # 5396) on 01-15-2012, 04:37 PM:

It's actually a weird constellation between Sony, RealD and Cinema.

The split-optic is developed and manufactured by (for) Sony and then sold to RealD.

Then RealD applies their common license scheme to it towards cinema owners. That is to keep conditions simple and the same for different types of equipment. So you don't actually 'buy' the lens. With the typical contract you pay an upfront fee of 10.000 US$ - be it then Z-Screen, RealD XL or XLS. But you don't own the 3D unit.

The same lens, with different filters, is used for the Panavision 3D variant on Sony projectors. RealD had it exclusively for polarizing systems only, so Sony was free to license it for the Panavision 3D system.

- Carsten

Posted by Chris Slycord (Member # 4239) on 01-15-2012, 05:30 PM:

--deleted; wrong thread--