The Ultimate 3D projection system: A Practical Discussion Thread - Page 19

Hi! It looks like it would be enough. I cut a small hole (4.5 cm x 4.5 cm, which is less than 2 inches x 2 inches) into a paper and put it in front of my projector and it seems that the light went through the hole ok, when it was close to the lens.

One should however in that situation need a proper filter holder or figure out how to make one by himself at lower cost. Any ideas there? I saw this kind of stand, but that's too expensive for me: http://www.3dimagetek.com/3DFilterStand.htm

Thanks again for all the suggestions!

3m scotch tape is cheaper. There is a picture in here somewhere of the OP's cereal box or some such thing made into a holder.

Ok, I decided to order this one, it seemed to be a good pack: http://www.anchoroptics.com/catalog/product.cfm?id=144

These would be good holders for the filters I guess, but you have to order atleast 500 or something like that from this place: http://www.talenco.fi/tuote/19544234...stilapputeline

I also have now a couple of linear and circular polarized (= Real3D) glasses and have ordered the Harkness Spectral 240 as well. Soon I will have everything ready

Wondering if anyone has explored more about driving a passive solution with dual projectors driven with PC-based content, not consumer movies. I have a chance to potentially work on a commercial stereoscopic application. I can't go more into than to say it involves over 10 projection screens to simulate a virtual training environment surrounding the users with screen walls. The spec calls for a high-end PC per screen to drive it with content developed by others, and the PC spec calls for at least dual Nvidia GXT480s in SLI on a Core i7 980, so it's high-end stuff. Question is (especially since it calls out for Nvidia), I thought they did not have a modern driver that allowed dual outputs to a pair of projectors for stereo? Isn't their stuff limited to 3D Vision, which is all active and uses a single projector? Anyone ever read of a way to run dual projectors from new Nvidia GPUs? Since the content will be custom written for this application I don't anticipate it playing nice with something like consumer 3D Vision drivers, and the spec calls for passive glasses, perhaps there is a solution here using dual 3D-XLs per screen? Or maybe even the client goes so far as to do two PCs per screen, one generating left-eye and the other right?

^^^^ Never mind, I read through the specification more on what I am working on and it seems they either want a single projector that can do passive 3D (like the new LG or some high-end Barco's, etc..) driven from one PC each screen, OR if using a pair of projectors for passive 3D, a separate PC will drive each eye's image from the stereo pair (2 PCs per screen.)

OR if using a pair of projectors for passive 3D, a separate PC will drive each eye's image from the stereo pair (2 PCs per screen.)

Good luck keeping that synchronized. Sounds like somebody spec'd hardware before figuring out the software, DoD contract I bet.

Mikemav,
You might want to also take a look at http://mtbs3d.com. There's a lot of wisdom over there for set-ups similar to what you're takling about.

You will probably be writing your own drivers so you can do whatever you want. You can use iZ3D or Tridef drivers to power dual projectors for passive right now without any 3DXL type device. This is the only to game at 1080p 60fps. I will probably set this up myself, and also do the dual 3DXL's for ps3/BR3D display. World of Warcraft really needs to be 1080p. It is amazing in 3D but I usually run 2D for the higher resolution.

Driving multiple PCs in perfect sync for a mega multi-display 3D presentation is not possible with consumer equipment. You'll need professional hardware, and advice because it's some seriously complex and expensive project.

There are a few very knowledgeable users are mtbs3d forums, but it's just a consumer forum, maybe you'll get some hints at what to look for but I doubt anyone there has ever worked on a project of such scope.

Matrox sells special cards that have in/out sync exactly for this purpose. Check with them.

people have multi-pc/multi-monitor microsoft flight simulator setups. Not 3D, but also not difficult, apparently. If you are doing passive 3D there is no 3D sync to worry about.

I have a passive 3D setup with dual projectors, synchronizing the pictures is my main nightmare when the software does not support the only display mode I have which supports perfect sync. And I'm using only one single computer.

Flight simulator multi-monitor setups use special software and add ons specifically for this game in order to produce the pictures. Their systems do not work with any application.
Also, I have never tried these systems but I do not know how tight their synchronisation is. The sync requirements for 2D are nothing like the ones for 3D.

It is possible to make such a system work with dedicated hardware and software but it isn't that easy.

Same nightmare as you BlackShark. This for several months wih 7 different graphic cards, ATI, NVIDIA and MATROX. I finally gave up and got a Matrox triplehead2Go digital to do the splitting outside. Windows source is sidebyside, using only one single DVI output (dual channel). For gaming, iz3D must be set to side by side. For 2D movies, I use the triplehead passthrough.

This is the only answer I have found and it works like a charm. Plus, videos can now use overlay and reclock. No more framelag, tearing or judder whatever. Everything is in perfect sync.

In my searching, I considered Matrox's genlock cards but they were too expensive for me. These should work for your mikemav if you want perfect sync between PCs, as they have been designed specially for that purpose.

Jack Bauer, when gaming with iZ3D in side by side, do you get the proper aspect ratio ? When I use it with Eyefinity, either the picture is stretched (the game renders 3840x1080 per eye instead of 1920x1080 per eye), or I get very annoying letterboxing.

Did you do any particular configuration in the iZ3D driver to get it working at the proper resolution and aspect ratio ?

So far I have never gamed in 3D. But, as color correction can be now done with my projector settings (I am using Dolby3D), I decided to give it a try.

So I downloaded a free demo of iz3D and installed Tomb raider-Underworld. Unfortunately, this was the wrong game. It has been reported as not working properly with iz3D and textures are not duplicated on both eyes. Maybe my low-end graphic card is involved as well, but I thought it was ok for a try.

What I could see was that ratio seemed ok though, with no special adjustment. Pictures are actually side by side, so splitting with the triplehead2Go shouldn't be an issue.

If I decide to go gaming, I will have to get a more powerfull card and I'll let you know about the driver.

Try Tomb Raider Anniversary or Devil May Cry 4. Both work very well and work fine even with modest computers.
Demos should still be available somewhere on the net.
With the side by side mode on my computer the iZ3D driver renders either squashed or letterboxed but never works like I want it to.

edit :
I spent the afternoon with the latest iZ3D beta and it has a "span mode" hidden in the config.xml file. I managed to make it work. YES !!!! it's good to be able to play UT3 and Devil May cry 4 on the big screen without the 1-frame-lag issues.
Not all games work though, it's a completely new and experimental feature : there is a huge bug with source engine games (Can't run Portal 2 on the big screen yet )

I was hoping I could buy two affordable 1080p projectors, cheap filters for each, a computer program or converter to output a L and R image to each projector and project onto a silver screen. Can this be done yet and easily?

curtishd, you can do that to play computer games. However, there are no 3D Bluray software players that support dual projection. You would also need 2 Optoma 3D-XL converters and a hdmi splitter and a PS3/3D Bluray standalone player to play 3D Blurays. I have heard rumors Tridef is working on a software BR3D player. Tru3D has the 3DXL for 299 with no dlp link glasses(which you wouldn't want anyway) so 600 more than your list plus the player if you don't have one.

So let me see if I got this right:
PS3 to spliter then each to a 3DXL and then to a left and a right projector?

I see a 3D modulator on the tru3d site that, if my understanding is correct, makes shutter 3d into passive 3D on the glasses end. I think you basically plug it into the sync control on the projector and it converts to passive when it passes through the lense. I like this idea as it seems to be the best of both worlds, you get active shutter quality but passive glasses and possibly less ghosting than passive.
Anyone have/try it?

It's not the best of both worlds, it only does passive with a single projector and it has serious drawbacks :

-no consumer projector outputs the sync for this device, you'll need a professional one
-you get the drawbacks of shutter (time sequential presentation and flicker)
-you get the drawbacks of polarised (mandatory silverscreen and ghosting similar to passive polarised)

So you guys say that 3d projectors better than any 3d Tv today?

I think so

By far. The big screen definitely makes a difference in 3D.

Think about theory for a second:

In the 2D world, you only have to move forward/backward from your screen to get an optimum angle of view, say 33° as THX recommends. Beeing close to an 50" screen or farther from a 100" screen give the same angle of view. Your visual experience should be the same, to some extent (at least in a very dark room).
That means everything is relative.

In the 3D world, you add an absolute parameter: your eye spacing (around 2.5"). Everything is not relative any more. So you have to stick to the screen size the movie was made for.

It is a known nonsense that a 3D movie, dedicated to be watched in a theater would give the same experience when projected to a smaller screen.

We are helpless on that, so: The bigger screen the better.

So no passive 3D yet? Any future plans from any projectors?

Does this sound right? What projector (cheap) do you recommend? Seems pretty simple. Any have or try this set up?

"Any have or try this set up?"
Wow, that is what the whole thread is about. Maybe start at page 1.
If I was starting from scratch I would go with the Benq W1000 dlp. It is around 1k, so 2k for two. It doesn't have lens shift so you will have a tiny bit of keystone correction to get the images to line up.

I wanted to maximize value for money, I picked up mid-range Epson LCDs (fullHD with lens shift).
The 3-LCD architecture polarisation pattern isn't the best for polarised 3D but it still works in some cases.
See the link in my signature to see how it turns out (i do not use a splitter : my only source is a computer so I plug the projectors directly to the computer)

Why do (most) LCD projectors have R&B at 0 degrees and G at 90? Is that an intentional design decision? Is it the LCD panel itself that polarizes the light, or is there a separate filter in the light path? Assuming it's a separate filter- can the green filter be rotated to 0 degrees?

It's because of the internal structure of these LCD projectors.
Most of them are 3-LCD, which means there are 3 separate panels , one for each primary colour.

The LCD panels output polarised light (that's how LCD works), but then the 3 pictures are assembled by a set of mirrors and prisms, which modify the way the light is polarised.



LCoS also produces polarised light but since they're single panel (one panel produces all 3 primary colours) they're all polarised exactly the same way.
DLP produces non-polarised light

3-LCoS or 3-DLP could produce polarised light with different polarisiration for each primary colour, or not. It depends on how the picture is assembled.