Film-Tech Forum ARCHIVE: Sony/Real-D adapter in 2D mode looks horrible, why so bad?

This is topic Sony/Real-D adapter in 2D mode looks horrible, why so bad? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Lyle Romer (Member # 1266) on 07-25-2015, 11:28 AM:

I saw "Terminator Genisys" yesterday at a Regal on a very small screen (20 feet wide). They had split shows between 2D and 3D. The Real-D adapter was in place for the 2D show (as it probably is even when they aren't sharing the screen between the formats).

I was seated about 20 feet back from the screen which was just short of half way back. I could CLEARLY see the pixel grid. Not just on text but I could see it during normal scenes.

Why does this setup look so terrible showing a 2K image? Is it just that they are magnifying the 1/4 of the chip so much that it makes the space between pixels much larger on screen than a 2k DLP setup?

Posted by Carsten Kurz (Member # 5396) on 07-26-2015, 07:45 AM:

Without knowing anything about their setup, it's impossible to judge.

Maybe they simply have the wrong lens installed. The 3D lens allows for a lot of electronic scaling and skewing in the projector. If you see something like a pixel grid under these conditions, there must be something completely wrong. Also, maybe you mistook the screen perforation for pixel grid?

Techwise, a properly set up split lens on the Sonys should hardly be able to display a visible pixel grid, for numerous reasons. That doesn't mean it is perfect, it has quite a few flaws, but a visible pixel grid?

How do you know it is actually a Sony system in use there? Is Regal 100% Sony?

- Carsten

Posted by Buck Wilson (Member # 5885) on 07-26-2015, 08:25 AM:

Regal is NOT 100% Sony. They did do a huge conversion with Sony though at some point so there is a large number of them.

Posted by Paul Mayer (Member # 355) on 07-26-2015, 09:49 AM:

Regal initially did go with Sony for the majority of their first big wave of digital installs in 2010. But later they went back and moved the Sony installs to smaller screens (I believe 38' screen width became the new max for Sony installs given that 4.3kW was the largest lamp that could be fitted). The Sonys where replaced with either NEC or Barco on the bigger screens. I did a lot of those Regal/Sony and NEC installs in 2010 and 2011, with many of the Sonys using the Real-D XLS twin-lens for the 3D installs.

Posted by Lyle Romer (Member # 1266) on 07-26-2015, 11:57 AM:

quote: Carsten Kurz
How do you know it is actually a Sony system in use there? Is Regal 100% Sony?

I could see the two images coming from the port hole. I don't think they would have had a DLP projector with Real-D XL on a 20 foot screen. Not that it means a ton but they did show a "Sony 4k" snipe before the feature as well.

Also, it was definitely a pixel grid and not screen perfs. I could see clearly defined squares. Also, when there was text, the jaggies were right along the square borders.

Posted by Carsten Kurz (Member # 5396) on 07-27-2015, 05:20 AM:

From my experience with our own Sony, I can tell you that it is nearly impossible to actually see imager based 'squares' or 'jaggies' on a Sony. The pixel pattern is completely different from a DLP, and it runs diagonal, so it doesn't run up with horizontal/vertical line patterns e.g. in credits.

I can not see a clear pixel shape on our Sony when I blow up the image through the 2D lens at max zoom and stand close to the screen. And with two overlapping images though the 3D lens, it should be completely out of the question. You should be able to see a blurred image, yes, but a discernible pixel pattern?

And yes, a double image on the portglas is no clear indication of a Sony splitlens.

Again, it could be, as some have mentioned, that this system has been moved from a larger house to this screen with the same lens, and now the lens is wrong or has not been adjusted optically for this screen, so that they had to use excessive electronic scaling to fit the image. That way it is possible you saw the actual resized image pixels, not a pixel pattern of the imager. Knowing that, of course, doesn't improve the experience by much. ;-)

If chosen and set up properly, the splitlens will allow you to use close to 2k image resolution in 3D and 2D mode, there is only a few pixels lost, and for scope, it actually uses more display pixels (around 2500) than on a native 2k system. Then overlaying and converging two images will blur the image somewhat.

This is a picture of 4k SXRD b/w patterns (left 4k, right 2k pattern). You can see the diagonal pattern on the checkerboard

https://dl.dropboxusercontent.com/u/5582554/belcourt.jpg

That is 12m image width and the picture was taken with the camera about 40cm from the screen surface. It's an A4 sized paper overlaid on the screen to get rid of the perf holes for the photo.

- Carsten

Posted by Lyle Romer (Member # 1266) on 07-27-2015, 05:41 AM:

Carsten,

Those pictures are very interesting. The grid I saw was definitely not diagonal like your image shows. I don't know what the heck was going on.

It looked like the movie was projected by one of the old, low resolution, LCD projectors that used to be used for pre-shows.

Possibly the wrong lens and scaling effect was the issue. I doubt they'll respond but I'll email Regal about it. It truly looked terrible.

Posted by Steve Guttag (Member # 268) on 07-27-2015, 06:42 AM:

Where I've seen Sony running with the split lens really fall down are things like picket fences in the movie...particularly if there are any image pans...the picket fence just breaks up. I've never seen a good 2D image out of the split lens, myself but since they are inherently on a silver screen that are many factors that may be mixing into that.

Mind you, I'ver never see a great image though a Real-D XL either...there are always misalignments with it somewhere in the image and just forget it if the screen is curved

Posted by Carsten Kurz (Member # 5396) on 07-27-2015, 07:25 AM:

Yes, there's loads of parameters to adjust in split lens/3D mode. If done properly and if the projection geometry allows, you can have a 1:1 2k pixel representation in 3D mode.
Some techs may take short cuts on the mechanical and optical alignment part and then tweak it electronically because it looks easier to do.
If you screw it, there may be loads of scaling involved until the image reaches the screen and that will show typical artifacts.

- Carsten

Posted by Marco Giustini (Member # 4544) on 07-27-2015, 11:21 AM:

Carsten,

Are you suggesting that the same pattern doesn't show diagonal lines on a DLP machine? As far as I can see the matrix is 'straight' on a SXRD machine, and I wouldn't expect anything different from that.

Posted by Carsten Kurz (Member # 5396) on 07-27-2015, 11:35 AM:

Marco - look at the picture I linked to above. Pixel shape and orientation is very different. It's a bit like screen angle for raster-printing. The 4k B/W pixel raster looks very different between DLP and SXRD, also the pixel shape and features. There is also a white paper from Sony depicting this.

- Carsten

Posted by Marco Giustini (Member # 4544) on 07-27-2015, 12:39 PM:

I don't follow that, could you link the Sony paper please?