ghosting in rear projection and silver screens measured

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thegardener
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Joined: Fri Dec 07, 2012 5:10 pm
Location: Germany

ghosting in rear projection and silver screens measured

Post by thegardener »

Moin

Some time ago our institute decided to built a small polarization based 3D projection system for scientific visualization. When talking to the silver screen manufacturer, he claimed that ghosting (aka crosstalk) would be worse with circular polarizers than with linear ones. I didn't want to believe this and so we set out to a little detour and actually measured crosstalk and scattering ratio for 3 silver screens and 3 rear projection screens. And being scientists we went on and published our measurements in the new Springer Journal 3D Reserach (which you will most likely not have access to if you are not at an university). And we uploaded them at the free-access preprint repository arXiv. Actually, that is even the better version of the paper because Springer did a crappy job on the figures and one referee stopped us from disclosing the trade names and company name (ScreenLab) in the journal article.

BTW, it turns out, the guy was right. But the crosstalk is still acceptable for circular polarizers and so we went with this solution; especially as we now also got a nice Smart Crystal Pro polarization modulator from Volfoni (not tried yet).

I hope this is useful to some makers

the gardener

Disclaimer: I have no financial, personal or other relationship to the screen manufacturer mentioned here; they just happened to sent us some samples.



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Last edited by thegardener on Sat Dec 08, 2012 5:00 am, edited 2 times in total.
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cybereality
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Re: ghosting in rear projection and silver screens measured

Post by cybereality »

Thanks, that sounds like a cool setup.
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Likay
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Re: ghosting in rear projection and silver screens measured

Post by Likay »

Just some extra extra information. I have a dual projection rig since ages ago and have tried almost everything polarized with it. In my opinion it's best sticking to linear polarizers because you will always align your head straight horisontal when viewing stereoscopic material anyway. Besides distorting the colorreproduction (minor effect) circular polarizers also have a slight tendency of making the image a little "washed out" compared to linear, all due to the extra retarderlayers reqired for circulars. So, the image will look better using linear filters. There is one advantage with circular polarizers though. Extra glasses are really easy to find. Just visit your local real-d cinema.

Edit: Clumsy me forgot to say thank you for sharing all the datas! Thank you!
Mb: Asus P5W DH Deluxe
Cpu: C2D E6600
Gb: Nvidia 7900GT + 8800GTX
3D:100" passive projector polarized setup + 22" IZ3D
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