CurtPalme.com Home Theater Forum

yonexsp · Joined: 25 Apr 2006 Posts: 311

Would it not be possible to do a 3D stack by using Polarized 3D filters.

Any idea if there is content out there for such a thing?

Kiev Savoie · Joined: 25 Oct 2007 Posts: 432

someone was talking about this the other day. there was a link with a great article and some advice on an old video card that does the trick nicely. do a search on the forum, it should pop up.

kschmit2 · Posted: Thu May 28, 2009 2:14 pm Post subject:

sure that's possible.

I've seen such a setup in a museum a couple of years ago. It used 2 Sony HDIH2000 PJs with polarizing filters in front of the 2 sets.
You had to wear special polarizing glasses to watch them. The effect was spectacular.

ecrabb · Posted: Thu May 28, 2009 2:45 pm Post subject:

Yep. It's called passive stereo and you view with polarized glasses. The two main downsides are that you essentially cut overall brightness in half, and that you need to use a special non-depolarizing screen to minimize bleed.

https://www.curtpalme.com/forum_archived/viewtopic.php@t=15100.html

https://www.curtpalme.com/forum_archived/viewtopic.php@t=13008.html

https://www.curtpalme.com/forum_archived/viewtopic.php@t=4508.html

There was even a post a year or two ago from somebody who had a big stack of polarizers for a CRT for free/shipping... I didn't act, then tried to email the guy much later and never got a response. I was going to try it when I had two 12xx machines. Oh, well.

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garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

Half brightness? Do the polarizing filters cut out that much? Other than whatever the filters block, I would think you could have full brightness -- since each eye gets the full benefit of a projector. It's not like the shutter-glasses approach where each eye only sees half the frames.

ecrabb · Posted: Thu May 28, 2009 4:42 pm Post subject:

Yes, Gary - half. Actually, more than half. It's true that each eye gets the full benefit of a projector, but the polarizer in the projector cuts the light in half (by definition - it's a polarizer), then you lose some more through the glasses. So, while the stack is twice as bright to the naked eye, it's not even as bright as a single projector is (to the naked eye) with the glasses on.

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ecrabb · Posted: Thu May 28, 2009 4:45 pm Post subject:

OK, here you go...
From the Barco brochure in the first thread I linked to:

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

Wow, I didn't realize the polarization cut out that much. Interesting. Come to think of it, when I took my kid to Monsters 3D, it did seem kinda dim...

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4409 Location: Phoenix

Hello

We sold a few of these rigs in Michigan; the filters were called Z-Screens.

.

mp20748 · Posted: Thu May 28, 2009 7:02 pm Post subject:

Oh yeah, you'll loose a lot when viewing Stereo through the glasses. I have several of the BEST they have out there here at my shop.

They are battery operated. They use a single flat battery cell. If I told you what a pair cost, you would not believe me.. Shocked

Kiev Savoie · Joined: 25 Oct 2007 Posts: 432

Finally! an excuse for a quad stack! "I'm not being rediculous Honey, i need it for the 3D!"

ecrabb · Posted: Thu May 28, 2009 8:38 pm Post subject:

Mike, the CrystalEyes are for active stereo... We're talking about passive stereo with cheap passive polarized glasses. But, yes, the CrystalEyes are damn expensive. I think they were about $500/pair last time I was playing with them back in 2000/2001 time frame. Don't drop THOSE glasses!!! That's one of the advantages of passive stereo for large audiences... The glasses can be manufactured for less than a dollar.

Active stereo using the shutter glasses like you have are actually brighter I believe, and they'll work on any projection screen - front, rear, non-depolarizing or not.

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ecrabb · Posted: Thu May 28, 2009 8:45 pm Post subject:

Here's a CHEAP pair of polarized glasses... $0.50/ea!
http://www.rainbowsymphonystore.com/pol3dglas.html

Here's a pair that's a little less, um, disposable @ $3/pr...
http://www.rainbowsymphonystore.com/plaspol3dgla.html

I still wish I had like a 20'x20' room somewhere that I could play with sh*t like this... 3D projection, driving and flight sims... There's all this fun stuff I'd love to play with, but no room to do so. Sad

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yonexsp · Joined: 25 Apr 2006 Posts: 311

I guess someday there will be content on BD or download. With all these 3D movies, it's only a matter of time until someone sells a version for home.

@ extremely bright DLP's, a screen, some cheap glasses and a movie. Bob's your uncle, at home 3D

martinlandau · Joined: 21 Feb 2009 Posts: 10

Viewsonic has come out with a 120hz 3d projector. Also you can go to www.mtbs3d.com which is a 3d Speciality site and do a search for SPAR filters. These let much more of the light through, so you don't lose so much brightness, but they are very expensive and from what I have read are made for small digital projectors, but perhaps you can find some for a CRT.