| Author | Message | ||
     juj71 Rating: N/A |
I've read many threads about solutions that "almost work" and "may work" but has anyone been successful in projecting a signal from a laptop thru a projector or two onto a video screen. I want to do a program for about 100 attendees. (2000-4000 lumens on screen would be nice) Is this attanable? How much? Thanks | ||
| M.H. Rating: N/A |
Yes, It works but you must specify exactly what you need. The company for witch I work (Lightpseed Design) does this very often + I was giving asistence to for putting several such setups together ... Possible solutions: A) Active projection. 1) GeForce in your laptop, one InFocus DLP projector at 60 Hz. Low quality , very cheap, active glasses nessesery. Unfrtuantely DLP projectors supporting stereo in higer refresh rate are expensive ... 2) As one 1) but with some CRT projektro at e.g. 100 Hz (SONY ?). A bit trouble wiht ghosting ... Any projections screen usage possible ... B) Passive projection You need signal for two projector. Cheap solution is laptop with dual output graphic card preferabely Quadro 2 or 4 (does this exist ?). Or you will need CyViz (expensive) for signal demultiplexing. My suggestion: Send laptop to the hell and use normal PC with dual output Quadro ... The rest is easy. Any 2 identical projectors + polarizer filters + non-depolarizing projections screen preferably from Stewart materials ... Any other question ? | ||
| M.H. Rating: N/A |
P.S. do not forget that for your 2000-4000 lumens on screen in stereo you will need 6000-12000 projectors, realy hudge machine ... The light lose in the stereoscopic optic during procesing is about 75% (depends on method you use, study Barco materials for details) ... I have seen a relatively good setup using 2x 1300 lumen DLP and back projection. The light loose was compensated by the excelen screen Stewart material ... | ||
| juj71 Rating: N/A |
Thank you for replying to my post. The current system I'm using is a video which is on laserdisk which, thru s-video goes into a ImageTec stereovideo decoder(3DI-3000). That has two s-video outputs(L and R) which are converted to vga. Then each vga is split into 8 signals then the (L and R) vga are pluged into 8 V-6 headsets (Virtual Reasearch) along with the audio feed from the laserdisk. The system works great but I was limited to 8 people at a time. The project was killed and two setups like this are sitting in a warehouse. I want to try to get the project going on my own again. It would seem to me that I could just take the vga from the converters and go right into the projectors. I can come up with two smaller projectors to do a demo or some testing but where do I locate the correct polarizer filters and what is the cost of these filters? Thanks again | ||
| M.H. Rating: N/A |
You can find the filters in any photo shop. You can use standard photoaparate polrization filter. I bought a suitable one for (49 mm diameter) for 20 USD (you will need two one for each projectors). You will than need paper or plastic polarizating glasses. Th price is in the range 1-20 USD per pice ... The most expensive thing is the non-depoalrizing projection screen. You can: a) Buy a profesional one from Stewart. b) Buy a can of silver aluminium spray ( I use chrom- sivler color, 10 USD). Pain with it any flat surface (wood desk, hard paper desk). it will not have so hi light gain but it works .... After putting this all things together, put on your poalrization glasses, start projection, rotate the filter on your projectors as long as you will see correct image only in correct eye .. Enjoy ! | ||
| EFL Rating: N/A |
Which model of DLP projector works for stereo projection??? I've already tried a lot of DLP models and none seems to work in interlaced mode... Thank you | ||
| Anonymous Rating: N/A |
EFL It depends about what do you speak about ... No DLP projector work O.K. for interlaced mode, it is nosnence to try this ... Some low end InFocus DLPprojectors work O.K. in 60Hz mode for Hw page flipping ... Hi End Christie Digital DLP monsters work O.K. even in 100-120 Hz page flipping mode ... Almost all DLP projectros have no problems with passive polarized projection ... | ||
| juj71 Rating: N/A |
Has anyone had success with using 2 of the plus u2-x2000 projectors (2000 lumes 5.7lbs)? It would be a passive polarized system. Also is there an easy way to test a projector in the store before I buy it? Maybe with a lense attachment and a pair of glasses but do they need to be matched in any way? Also does anyone have an still image thatI could project? | ||
| Itsikw Rating: N/A |
You may want to consider my method "StereoBright" to make a dual-projector stereoscopic display. This is a very cost-effective method. Have a look at my site www.advisol.co.il Itsik | ||
| Maart Rating: N/A |
These are half-wavelength retarders you are using am I right? how does it work, and where can I buy the filters to tet them? do I have to make my own glasses to use with it? | ||
| ItsikW Rating: N/A |
Maart, You are right. I mount L/2 retarders on both projectors, and rotate both polarizations by 45 deg. This is good for symmetry and allows using standard glasses. Btw, if you mount L/4 retarders instead, you get a display with circular polarization. I use a L/2 retarding polymer which I laminate on a clear photographic filter. A convenient source for such retarding polymer is Edmund Optics. Unfortunately, their material is inferior. I am using a much better material, but it is not available yet commercially. Itsik | ||
| Larry Elie Rating: N/A |
Itsik, Couldn't you do the same thing from a field sequential input (NTSC A field= right and B field=left) by just processing the same sort of way into ONE projector? The A field would go into the normal (your PPT slide 13 top) while field B would use the orthogonal green info (your PPT slide 13 bottom). My guess is flicker would be minimum (LCD's are relitively long persistance) and you don't even need to allign. You would need active glasses of course, but the cost would be about 1/2... Or am I missing something? | ||
| ItsikW Rating: N/A |
Yes, you are missing. I do not see how exactly you mean to get the stereoscopic image. But, regardless, it is impossible to use LCD projectors with active glasses. Itsik | ||
| Anonymous Rating: N/A |
This information is wrong. Their is the Christie PA Converter which converts 2 passive signals back into one active signal for the usage with LCD projection systems. -Thomas www.porrmann-awater.com | ||
| Maart Rating: N/A |
nope Itsik is right. that is for dlp technology for active glasses and dual stream lcd for passive. and dont these converters look just like the cyviz ones? can you tell me more about your 3D Cinema Server? | ||
| Willy Le Maitre Rating: N/A |
with this StereoBrite technique is it nessesary to use passive glasses made from the same retarder polymer that is in front of the lens or do you use the passive polarizing filter glasses typical for passive stereo video projection? | ||
| itsikw Rating: N/A |
Willy, With StereoBright you use standard polarizing glasses. However, you must use a projector with a high polarization ratio, otherwise you will see a strong ghosting. Itsik | ||
| Sean Rating: N/A |
this thread is a little confusing. i have two XGA digital projectors i would like to use hooked to my nvidia dual display graphics card for so i can play 3d games. i am confused on a number of points. is my equipment bright enough? one projector is 1000 lumens, the other is 600 i think. what lenses and glasses and screens should i use? what is simple, cost effective, and easily reproducable? how in the world do i tell my graphics card to display the stereoscopic version of a 3d game onto the two displays? is there an red-blue anaglyph converter for nvidia 3d cards? so i could just try out projected 3D? any help would be appreciated, please email stereo3D@sean.keane.name | ||
| RyanUK Rating: N/A |
weeeeeelll you can start at www.more3d.com. they have software that will send seperate left and right signals for dual output cards. | ||
| Anonymous Rating: N/A |
Can I ask how you guys are mounting your filters to the projector? The projectors I have seen don't have a thread on the lense like a camera. Also, is half-wavelength retarder the same thing as a polarizing filter? Thanks | ||
| M.H. Rating: N/A |
half-wavelength retarder is something totaly different from polarizing filter ... polarizing filter polarize light ... half-wavelength retarder rotate the oscliation plane of aplready polarized light ... Accrding polarized filter montage: You must help yourself :-) ... Some montgae palec the filters e.g. several cm before the lenghts on special montage ... see: http://www.cyviz.com/products_products_viz.html | ||
| Anonymous Rating: N/A |
So why are some people using polarizers and other people using wave length retarders? What do I need to put in front of the projector and then in front of my eyes to allow/block the image? Thanks | ||
| M.H. Rating: N/A |
Anonymous: For most projectors you should use polarizers. For some special sort of projectors with pre-polarized light it is possible to use combination of retarders and polraizers .... | ||
| Anonymous Rating: N/A |
Would this be more for LCD as opposed to DLP, since I hear LCD tends to polarize the light more? Thanks | ||
| M.H. Rating: N/A |
CRT and DLP do not pre polarize light => only polarizrs have sense ... All LCD polarize light, but it depend on constuctions how ... Mostly G light 90 deg rotated to R and B | ||
| Anonymous Rating: N/A |
What should be use with DLP, linear, or circular polarizers? Does one have better light throughput than the other? Thanks | ||
| Anonymous Rating: N/A |
So, do some LCD monitors polarize the R,G and B values the same? Is this how itsikw is using a combination of retarders and polarizers? Regards | ||
| Nanni Brandão Rating: N/A |
what's the difference between linear and circular polarization ? I work with 3D max and I will try to get the polarize effect. I understand that I will need: 2 projectors LCD with polarized lens and glasses polarized to have the effect. Do I need any special software or player to to that? Thank you and Regards | ||
| M.H. Rating: N/A |
Linear and circular polarization are 2 different optical systems: 1) For linear ploariztion the light wave flickers only in one plane (e.g. horizontal for left eye and vertical for right eye) ... 2) Circual polarized light flicker only in one plane as well, but this plane rotate during time very fast (to left or right)... Differences: Circular optic is much more expensive and hard to adjust. But if you use circular system you can move you head during visualization out from horiz. position without limits (movement bigger than 8 deg for linear destroy stereo). IMAX use linear polarization ... For passive stereo you need: 1)2x projectors (preferably DLP, LCD works as well) 2) 2x polarization filters good dual projector montage 3) polarization glasses 4) non-depolarizing projection screen (essential !, quality of the screen material can send everything to the hell or save it) 5) nVidia graphic card with dual output (forget any ATI) 6) nVidia stereoscopic drivers (for games) 7) for movies some freeware specialzed movie player + 3D movie For eventual profesional usage I suggest Quadro nVidia graphic card + profesional software for hi resolution stereo video playback like my DepthQ. | ||
| M.H. Rating: N/A |
P.S. You need hi output projectors (better than 1500 ANSI). There is about 70% light intensity lose during the ploarization processing . And stereo images must be bright to look good (due to some physilogical acoomodation related effects) ... | ||
| Alatar Rating: N/A |
Hi M.H. Are you able to elaborate on what, in the context of the system you outlined above, the Quadro cards give you that the low-end ones don't have? I am using a clone FX5200 card and it seems to have no trouble at all keeping up with what I am asking it to do, but I would happily get a Quadro if I could think of a good reason for it. Thanks in advance, Alatar | ||
| M.H. Rating: N/A |
Alatar: I can do test on both Quadro and FX card. If you want to know main reasons why to use Quadro instead of normal nVidia for profesional applications, the key reasons are (do not read when you are a gamer): - OpenGL stereoscopy in window, this is a must when you want to do e.g. stereoscopic 3D MAX development or complicated 3D stereo video editing. You simply must have both a stereo windows and perfect 2D acces to contorl elements simultaneously ... - OpenGL stereo is much more stable than the consumer level stereo methods + works with all drivers versions. - graphic from applications like 3D MAX works on Quadro aprox 30% faster than on GeForce. This is generaly true for all OpenGl aplications (based on ViewPerf benchmarks results) - Quadro has the DIN-3 stereo synchronziation connector. Left/Right eye seting is always O.K. , screen images is not degradated by some pas througg dongle, glasses connections is 100% reliable. - Everything what works on GeForce works on Quadro as well (I mean consumer lever stereoscopic wrapers). They even cooperate witht he DIN-3 connector for shuterglasses ... - The OpenGl stereoscopy on Quadro makes palyback of super hi resolution stereoscopic movies possible (up to 2048x1536 per eye, 2048x3072 source). I know, this has meaning ony for middle size stereoscopic cinema instalations ... - Only the Quadro cards with genlocked outputs can eventualy drive multiple projectors realy correctly - Only Quadro cards can drive realy big LCD autosteresocopic monitors (3200x2600) I can continue, but, I thing this is enought for now .... ( I am NOT working for nVidia Quadro team :-) ) | ||
| Alatar Rating: N/A |
Thanks very much for the info, M.H. > - The OpenGl stereoscopy on Quadro makes palyback of super hi resolution stereoscopic movies possible (up to 2048x1536 per eye, 2048x3072 source). I know, this has meaning ony for middle size stereoscopic cinema instalations ... Actually, of all the items you mention, this is the one that is closest to my requirements. I had thought the DirectX BLT functionality was significantly faster than the OpenGL BLT functions. Is this not true for the Quadro drivers? Can you tell me which OpenGL commands/pipeline/approach manage to achieve this performance? Do you have a specific suggestion for a Quadro card that you know works well for stereo applications? Thanks (again) for your help and information, Alatar | ||
| M.H. Rating: N/A |
Alatar: The metods witch we use for speed up OpenGL stereoscopic video procesing is a proprietary know-how based on our (I mean LightspeedDesig) cooperation with nVidia developers. I can not discuse the technical details covered by NDA. According suggested Quadro model - it depens what terget video resolution do you need. For full PAL/NTSC pere eye (dual PAL or NTSC source) Quadro 2 MMX with 64 MB of videomemory is O.K ... If you want e.g. handele Stereographics SynthaGram 222 monitor at 3840 x 2400 (24 fps) and creat on the fly aoutostereoscopic pattern the Quadro 4000 FX is the only one with sufficient power ... But for video procesing hi-end CPU and fast standard memory is neccesary as well ... I had done tons of perfomance benchmarking ... If you will precisely describe your requirement, I can tell you what HW is good enought ... | ||
| M.H. Rating: N/A |
Alatar: P.S. if you realy need the mentioned information for some serious project, you should try to write to LightpeedDesign CEO (Chris Ward) an official letter and describe your needs. Maybe a NDA based information exchane will be possible ... In this case I will be happy to give you full support ... | ||
| Alatar Rating: N/A |
Ok, thanks for the information. This definitely is a for a serious project, but this current task is an offshoot of the main project, and to some extent a one-off. Also, I too am operating under NDAs for the main project, but not this current offshoot task, so it's a bit of a fine line to tread. If it's alright with you, I will send you an email on Monday so we can continue this on a more formal basis. |
