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Question about cellophane polarisation

Posted: Tue Dec 13, 2011 7:44 am
by nicooke
I just came across this article:

http://individual.utoronto.ca/iizuka/re ... ophane.htm

... and wondered - could this be done on a standard LCD TV? Would this not give (albeit lower resolution) 3d on a standard tv regardless of refresh rate?

SO basically a sheet of cellophane covers half the LCD screeen, polarising the right half, then you put on a pair of these:

http://www.amazon.co.uk/Linear-Polarize ... B003IPIAFQ

...and wouldn't you get a unique image for each eye? I realise of course the viewable area would essentially be halved however.

Re: Question about cellophane polarisation

Posted: Tue Dec 13, 2011 8:01 am
by bgnome
i would think this would be less than ideal as you are essentially only using have your display for each eye. i dont know much about the optics but i would think that you would have convergence issues as well unless you sat VERY close to the display.

it is much easier to use the cross-eye method without any need of extra equipment or display modification. you can also set up a dual display with the use of mirrors to get a much better result.

Re: Question about cellophane polarisation

Posted: Tue Dec 13, 2011 8:04 am
by nicooke
I can't do the cross-eye method, and this is for watching movies too. Just spitballing ideas :)

Would it also not be possible using a projector to split two sbs images using a prism and then bounce these off of a mirror via a polarising filter? Or am I barking up the wrong tree here?

Re: Question about cellophane polarisation

Posted: Tue Dec 13, 2011 9:09 am
by bgnome
nicooke wrote:I can't do the cross-eye method, and this is for watching movies too. Just spitballing ideas :)

Would it also not be possible using a projector to split two sbs images using a prism and then bounce these off of a mirror via a polarising filter? Or am I barking up the wrong tree here?
what, like this?
[youtube]http://www.youtube.com/watch?v=4X6ryEhnA3A[/youtube]

Re: Question about cellophane polarisation

Posted: Tue Dec 13, 2011 10:45 am
by Likay
If you just cover one half on the screen with the cellophane (45° clockwise rotated) and the other half 45° counterclockwise each eye will receive one half of the screen when using circular polarized glasses (depending on how close to a quarterwave retarder the specific cellophane now is...). However viewing crosseyed won't require any extra thingies and this solution will bring the same stress to the eyes as x-eye or parallell viewing.

Splitting a beam from a projector is possible but i'm not certain the results are guaranteed to be good. Just make sure that both left and right eye beam travels an equal length to the screen. Keystoning could be a problem.

Re: Question about cellophane polarisation

Posted: Tue Dec 13, 2011 6:47 pm
by cybereality
You could just get some stereo prism glasses, probably a lot cheaper and easier:
http://www.amazon.com/3-D-Stereo-Prism- ... B00465OY3Y" onclick="window.open(this.href);return false;

Re: Question about cellophane polarisation

Posted: Wed Dec 14, 2011 10:29 am
by nicooke
I did see those prism glasses - Would these actually be any better than Colorcode anaglyph on my 42inch tv? How much do they affect the perceived size of a screen? I need to be able to sit on the sofa and dual projection sin't really an option in this flat so something for the future I think. As such its looking like sticking to Anaglyph for now but I was wondering if there was anything better for low cost.

Re: Question about cellophane polarisation

Posted: Wed Dec 14, 2011 3:46 pm
by bgnome
it looks like you are trying to find s3d solutions for your standard hd lcd tv?
i would guess anaglyph would be the easiest thing to implement, although you will have varying results depending on which method you try.

i have heard of standalone hdmi 1.4a adapters that will allow you to pageflip your screen at 60Hz instead of 120Hz, but at that price it would be much cheaper to just buy a new 3DTV. There are many screens under 40" that have become very affordable, especially now with the holiday season and the end of the fiscal year sales.

Re: Question about cellophane polarisation

Posted: Wed Dec 14, 2011 4:50 pm
by Fredz
Prism glasses are better than anaglyph for 3D, but not really suited for viewing an entire movie because you need to keep your head perfectly still. Another drawback is the lower resolution and image size (the screen will be divided in two horizontal parts), but the advantages are no ghosting and perfect colors. It's still more comfortable for the eyes than cross-eyed viewing though (with or without cellophane).

Re: Question about cellophane polarisation

Posted: Thu Dec 15, 2011 2:50 am
by nicooke
I am trying to find 3D solutions for the normal HDTV at 60hz. Pageflipping at 60hz sounds good but I think you are right about prohibitive cost.

Honestly, Colorcode really isn't that bad on my TV at all - only problem really I've noticed is on the Shrek Dreamworks intro sequence - when the fishing line whips out of the screen it really does whip out, but I see the blue and yellow for a second. Otherwise I'm more than happy with it. In comparison, red/cyan and green/magenta lose pretty much all colour for me.

I only got this TV about a year ago so I think I'll need to wait for a while before changing it - probably for a lenticular display in a couple of years.

Many thanks for all your help - I'm sure I'll come up with another hair-brained idea soon :)