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David6768

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Posted on Friday, February 24, 2006 - 3:47 am:   Edit PostDelete PostView Post/Check IPPrint Post

How effective would it be to set up a passive projection system using regular DLP projectors? The off the shelf DLP projectors don't have the lens shift to line up the images perfectly, can I still get great results from this setup or am I going to be displeased after spending all of the money to make it happen. I currently have a LCD projector so I would have to buy two new DLP projectors not to mention everything else ? I still figure I can get everything for about $2500- $3000 depending on the kind of deal I can find on the projectors. This way if I ever want to get rid of the system I will at least have 2 regular projectors to put up on Ebay vs one $4000 specality projector (DepthQ) that i think I would loose my butt on with Resale( not enough of a market) any ideas? I've got the 3D bug now.
Thanks
David
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Alatar

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Posted on Friday, February 24, 2006 - 2:55 pm:   Edit PostDelete PostView Post/Check IPPrint Post

It works extremely well, but you will find it very hard to come in under $3K. A decent polarization-retentive screen alone can cost that much.

You don't need to worry about exact alignment, we spent a lot of time on this issue in our original designs but later discovered that you can't see alignment errors below about 0.2% (i.e.about 2 pixels off on a 1024x768 image.
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david6768

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Posted on Saturday, February 25, 2006 - 1:32 am:   Edit PostDelete PostView Post/Check IPPrint Post

Da-lite sells the silver matte screen. I talked with them on the phone today and they stated that their screen would not depolorize the picture. $285 for a 60x80 pull down screen. Any comments on their screens? I am not setting up a business so it just has to please me. Any ideas where the best place is to get the polorizing filters?
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david6768

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Posted on Saturday, February 25, 2006 - 1:37 am:   Edit PostDelete PostView Post/Check IPPrint Post

ug er I mean polarizing twice :)
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Alatar

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Posted on Saturday, February 25, 2006 - 2:10 am:   Edit PostDelete PostView Post/Check IPPrint Post

Should be fine if that's the size you are looking at. I was thinking more in the range of 15' diagonal or so.

I'm afraid I can't help with a filter supplier as we get ours from our parent company which buys them in bulk. However, you might look at Edmund Scientific etc.
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Alatar

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Posted on Saturday, February 25, 2006 - 2:15 am:   Edit PostDelete PostView Post/Check IPPrint Post

I just realized that if you are going to use a screen of that size, you might well have an alignment problem as it will be hard to avoid keystone distortion in one or the other projector. So I take back my original comment about alignment not being a issue. You might want to try some kind of test to establish how much keystone distortion is going to misalign the tops (and bottoms) of the images.
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Hornet

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Posted on Saturday, February 25, 2006 - 2:27 pm:   Edit PostDelete PostView Post/Check IPPrint Post

Hi
with active DLP 3d stereo system are results wery good and the price for this is half or more cheaper.
I think only 1 reason is for use of passive system - the possibility of presentation for more peoples - the polarising googles are cheap.And passive system is practically flickerless.
On the other side passive setup is expensive - 2 projectors, screen, filters etc.
I have active and cheap 3d stereo home system and I really satisfied.
My setup:Athlon 3200+,NV 6600 GT, 512 MB RAM, Benq PB 6240 (2700 ANSI, DLP, max 86Hz refresh) projector. E dimensional wired shutterglasses. No screen only white wall. Option is wide angle adapter lens for 20% magnification of picture. This use I for flightsims, games, movies.
Cheap and effective.
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Alatar

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Posted on Saturday, February 25, 2006 - 4:38 pm:   Edit PostDelete PostView Post/Check IPPrint Post

But are there any reasonably-priced active DLP systems that run at a resolution above 800x600?

We are in the process of switching over several of our stations from active-CRT 1280x1024 to passive-DLP 1400x1050. The animators frequently complain about the lack of detail at 1280; I can't really move them down to 800!
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david6768

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Posted on Saturday, February 25, 2006 - 6:48 pm:   Edit PostDelete PostView Post/Check IPPrint Post

oops sorry 60X80 inch 100" diagonal screen not 60 X 80 ft.
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Hornet

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Posted on Saturday, February 25, 2006 - 7:11 pm:   Edit PostDelete PostView Post/Check IPPrint Post

I use home cheap DLP Benq PB 6240 XGA 1024x768 max stabile refresh 86Hz!, 2700 ANSI, VGA input (cca 1000-1200 EUR) and shutterglasses, and the results are from my sight very good. Flicker is minimally, is litle L/R color difference - absolutly no problem in 3D and 1 frame delay (R/L must by reverted).
The best way is self testing - i think this is possible.
The important factors for DLP projectors for 3D stereo are:
max possible refreshrate and light output.
Some 1280x720 projectors are only with max 74Hz refresh. The expensive HD 3 chip DLP are good candidates for 3D stereo.(BARCO SIM plus,CHRISTIE MIRAGE S+4K etc. Only one problem - price, is for this proffesional use no problem)
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Bill

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Posted on Sunday, February 26, 2006 - 3:55 am:   Edit PostDelete PostView Post/Check IPPrint Post

I have the Da-lite silver matte screen and use it with a dual DLP projector system. It is not outstanding, but it is also not bad. I get rich colorful XGA 3D, and I am using it for three years now with no visible deterioration of polarization. There are are certainly better and more expensive silver screens on the market (e.g. Steward), but Da-lite has a pull down version that allows you to hide the screen when not in use.
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M.H.

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Posted on Sunday, February 26, 2006 - 11:33 am:   Edit PostDelete PostView Post/Check IPPrint Post

Passive:
The key problem is you can not to use this setup in 2D mode eficiently .
Resons
- without totaly perfect alighmend, the 2D mode looks bad, it is impossibel to watch it without glasses. Perfect alighmendt on pixel precisinon level require expensive projectors with aretabele lens shift ($4000 per one and more)

- you can swith theoreticaly oen rpjector off for 2D. But thsi will produce diferent lamp burn of this proejctors = diferent light intensity = corrupted stereo later.
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M.H.

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Posted on Sunday, February 26, 2006 - 11:38 am:   Edit PostDelete PostView Post/Check IPPrint Post

Da-lite silver matte :

We had made realy careful testing of all available non-depoalrizing material on the market.

Results:
The only one witch can be relay be used in praxis are Stewart and SilverFabric ....

Head to head comparison of DaLite material shows it depolarize about 3 times more than the mentioned mterials + it has low ligth gain.
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David6768

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Posted on Friday, March 10, 2006 - 3:48 am:   Edit PostDelete PostView Post/Check IPPrint Post

Alright I have the linear filters and my new Da-lite silver screen here at the house. I ordered two NEC LT180 projectors and they are on the way. I had to go with that particular projector due to the lens throw distance. (small room) The last thing I am going to need is a dual projector ceiling mount. Any ideas? I have looked at one from Perfect Mounts but it is going to run me about $600, I don't know about you guys but $600 for a projector holder seems a bit steep. Anyone know of any other models or any cool ideas for making one? I slapped a $15 speaker mount on a $20 under the TV VCR bracket for my last ceiling mount and it looks as good and is as adjustable as any ceiling mount I have seen. I don't have any ideas for a dual setup yet though.
David
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Alatar

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Posted on Sunday, March 12, 2006 - 7:31 pm:   Edit PostDelete PostView Post/Check IPPrint Post

Ideally you need a mount which allows smooth and reliable adjustment of each projector's roll, pitch and yaw. The adjustments for each should be easily accessable and not be impeded by the other projector.

Note that I say "smooth and reliable" because most of the ones we have tested are neither of these. Specifically:
- they have positions that the adjustment cannot be locked at (for example, if you try to lock the roll at 0.08 degrees, tightening the screw causes it to slew to 0.09 or 0.07 degrees);
- adjusting it in one dimension affects the other dimensions as well; and,
- adjustments become harder to achieve as the mount is used more and more (only really an issue for equipment that goes on the road a lot).

We contracted a local company to come up with a design that met our requirements, the result is exactly what's needed but they charge about $1,200 per mount.

You could also buy two standard Dell Universal mount kits, one part of this is a mount block with built-in roll, pitch and yaw adjustments. Then keep said part, ditch the rest, and attach the two mount blocks to the ceiling using a 1/2" x 2" steel bar. But you are still well over $500.

FWIW I share M.H.'s skepticism about Da-lite surfaces, they don't really compare with the other two.
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M.H.

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Posted on Sunday, March 12, 2006 - 8:21 pm:   Edit PostDelete PostView Post/Check IPPrint Post

David. We have asses tot the moutns you need, but the price is $1200 as well + $200 for customziation for given projetor. All projectors have 4 DOF, evrtything si areatable.
http://shop.gali-3d.com/katalog_detail/katalog_detail.php?id=47

Hint: try to find a used one on E-bay !
We had bouth there 2 one for $100 or so ...
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itsikw

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Posted on Tuesday, March 14, 2006 - 11:02 am:   Edit PostDelete PostView Post/Check IPPrint Post

Hi David,
I hope you are not planning to use the StereoBright filters with the NEC LT180. These filters work only with LCD projectors.
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david6768

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Posted on Saturday, March 18, 2006 - 4:00 am:   Edit PostDelete PostView Post/Check IPPrint Post

no I am not planning on using the Stereobright lens' with the NEC projectors, I mainly wanted the mount and your mount and lens combo was cheaper than just the mounts sold by others.
Thanks
David
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david6768

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Posted on Saturday, March 18, 2006 - 4:05 am:   Edit PostDelete PostView Post/Check IPPrint Post

LOL you guys are always ready to throw out an advertisement. I say I don't want to buy a DepthQ because they are too low of resolution for the price then someone suggests I buy 2 to increase my resolution. Now I say I think $600 for a piece of aluminum that will hold a projector and someone pipes in with buy our $1400 version. I will make one or go to a machine shop and have something built for 1/3 of that.
David
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itsikw

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Posted on Wednesday, March 22, 2006 - 11:17 am:   Edit PostDelete PostView Post/Check IPPrint Post

Why didn't you tell me? I would have sent you polarizers instead of the retarders.
But anyway you are right, the filter mount by itself is a bargain.
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david6768

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Posted on Thursday, March 23, 2006 - 2:42 pm:   Edit PostDelete PostView Post/Check IPPrint Post

I should have, I did want to see how well the Stereobright filters work in comparison though. I have only one LCD projector but I will be able to get an idea of how well they work from the amount of bleed through I can see on the wrong eye. At the time I ordered the kit I was having a hard time finding a DLP projector with the short throw len' that I was looking for so I was thinking I might have to go with dual LCD projectors. Since then I have found the DLP projectors I need. I have everything here it is just a matter of mounting the 200LB screen to my wall now. I have several screens here at the house but I can tell you that the Da-Lite screen is a monster. The metal case the screen is in weights a ton, so I am going to have to go stud hunting in my wall and find a good strong bracket to hold it up this weekend. Then it should be grand. Thanks for everyones help
David
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Hornet

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Posted on Thursday, March 23, 2006 - 8:27 pm:   Edit PostDelete PostView Post/Check IPPrint Post

David6768
Please performe test with normal XGA DLP and shutterglasses, I have this setup (XGA) and for home use this is very good, no problems with screens, mounts, filters ,only white wall for projection is needed.
My 86 Hz refresh (2700 ANSI !)is no so bad,of course.The passive proj. for home use is more complicated and expensive, I totally satisfied with my result. And this is simple, cheap and XGA. Testing is the best way for succes /this was my way/.
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david6768

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Posted on Friday, March 24, 2006 - 3:36 am:   Edit PostDelete PostView Post/Check IPPrint Post

I tried a single XGA DLP projector and the results were good when watching dark titles like Encounter in the Third Dimension but poor if I watched anything that had lighter scenes. On the lighter scenes I could clearly see the scan lines from the 1/2 resolution images. I was only able to view the DVD's as Razor3d recommends at 640 X 480 @ 60HZ anything higher and either the projector was deinterlacing the images or the shutterglasses weren't keeping up as there was serious ghosting. I was using Cyberdvd's software with H3d as razor3d suggests. I have not yet tried Stereoscopic Player at higher resolutions. I will be setting up the dual projector system tomorrow as I am off of work and I will have the time to setup the screen and projectors. I was using the NEC LT180 today, tomorrow I will be using 2 of them. They are going for $799 including shipping on projectorcentral.com not bad for an XGA projector with 2000 lumins and 1000:1 contrast ratio. Thanks for the advise.
David
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Hornet

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Posted on Friday, March 24, 2006 - 11:57 am:   Edit PostDelete PostView Post/Check IPPrint Post

OK, I use my setup more for sims and games, and for this is active setup OK.
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david blankenship (David6768)
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Username: David6768

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Registered: 4-2006

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Posted on Tuesday, April 04, 2006 - 1:07 pm:   Edit PostDelete PostView Post/Check IPPrint Post

I am having trouble with Stereoscopic player. When I set it up for dual screen output and to interlaced video, I can see ghosting on each individual monitor. I should have the left eye going to one monitor and the right eye going to the other so both monitors should show a 2d image. Could someone tell me the correct settings for the software? I am using a Quadro 4 card and have tried many different settings with no sucess. I am trying to view Edimentional DVD's such as Encounter in the Third Dimension. Ultimatly I will be running a passive system but until I get the individual displays to work correctly I am at a standstill.
Thanks in advance.
David

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