The Ultimate 3D projection system: A Practical Discussion Thread - Page 60

Basically it appears to be a polarization module. There are several brands out there right now. I really want to try one of these modules out especially with the W7000 as I think ghosting will be very minimal and really bright. As for silver screens, they can be expensive but if you make your own of buy it can be cheap. I have silver screen samples from about 4-5 companies and I bought a Harkness silver screen for cheaper that all these other screens are it looks great (I have not tested passive 3D but it appears to have great extinction ratio).
I wish more companies would let fellow AVS member review products.

I still think that if there was an Omega polarization modulator lots of people would buy it for great passive and simple 3D. Is it even possible to make a modulator using the Omega technique?

The adapter or Polarization Modulator is made by Volfoni.com. It costs USD1500 with 5 pairs of passive glasses. Believe they have different modulators for DLP, and LCD /Dila projectors.

we actually looked at making something like that but ours would have to be a wheel that would sync to the IR output for shutters and it would be costly as it looks so far. more than possibly bying another projector and you would not have as bright of an image along with it not being a constant passive 3d image. we actually started to have a prototype made but its stalled for several reasons.

im actually working on something way better. it will be a single projector passive system, DLP with no rbe our filter tech.... cant say too much
Edited by motorman45 - 6/30/12 at 6:58pm

Ahhhhhh come on. I am thinking of buying a W7000 and have questions before I take the plunge like what dlp projectors will work? When might this be out? Can I be a beta tester!? Come on tell us more...

A projector in which you replace the traditional DLP colour wheel with an Omega specialized colour filter ?
(just guessing)

How large a screen do you think rs40 double stack is capable of? For 2D and 3D. What did you finally settle on for a screen? I am hoping to do a 13' wide 16:9 screen.

not quite, it would have our filters in it but sequential cycled multi led based source. no moving parts, high lumens correct color....

Now something that I'm confused on is how many degrees a quarter wave plate retards and a half wave plate. Simple math would indicate 90 and 180 respectively, but I've read conflicting details. Could someone clear this up? I have the same set up as rdjam and to get optimum transmisivity I know I need to change the polarization from horizontal to vertical. Any thoughts?

now this sounds interesting... assuming a legally binding agreement with a partner precludes detailed discussion. LED light source appears to minimize RBE... introducing a color filter with more bands would presumably not introduce significant RBE at 120Hz. If it can be pulled off while maintaining top-notch 2D, I think I should start saving my money. Can you think of any reasons we might pay attention at CEDIA?

LED light source with high lumen, sounds expensive
Sequential multi LED sounds like a full set of LEDs for each eye view matching the Omega band filters : dual LED light engine, sounds even more expensive !

I guess I probably won't be able to afford it, unless there is a trick somewhere.
I'm not a physicist but according to what I've read on the internet,
-a quarter wave plate makes polarisation circular
-a half wave plate or a stack of two quarter wave plates rotates the polarisation by 90°
Edited by BlackShark - 7/4/12 at 4:54am

yes totally right, quarter wave plate in a linear polarized beam makes circular. but add one more and it partially returns to linear. ive got all the parts and several types of quarter wave plates at work and the second one kind of turns it 90 deg but none of these plarizers are 100% effective at changing polarization.

sorry somehow i inserted my response in the quote.

Yeah, I need to change the polarization of my projector from horizontal to vertical before it enters the circular polarizers. I just needed to figure out which one to use and how many.

You should be able to do that with a half wave plate (or two quarter wave plates) set to rotate the linear polarizaton to a vertical orientation, The half wave retared plate is followed by the circular polarizing filter, which consists of a linear filter element and a quarter wave retarder element. The orientation of the circular filter needs to be such that its linear filter component has a vertical orientation. I discussed this in Part 6 of my series of blogs on Passive 3D Projection at projectorreviews.
Edited by Ron Jones - 7/7/12 at 12:56pm

I have a question for those of you using the Optoma 3d xl boxes and a HTPC: which software are you using for playing 3D? I have been using PowerDVD 12 but I am having issues with their 3D and the optoma boxes. When ever I try to enable to 3D the video signal will flicker back and fourth a few times and then go blank. I have to close PowerDVD to get the regular windows screen back. Which 3D playback settings in PowerDVD do you guys use? Thanks so much for your time and help.

I'm curious as well about Powerdvd12. I can't get it to do 3d at all with a dual projector setup. Is their a trick or does it just not work?

Are you using the optoma 3dxl boxes as well? What graphics card are you using? Going directly from the graphics card to both projectors?

I have two Benq W7000 projectors with a splitter that connects into the 2 3DXL boxes which feed into the projectors. The video card is is Nvidia Gforce 440 . I have that hooked up to my Denon AVR 2313C1. I plan on getting another HDMI cable to replace the spliter. It tends to blank the screen every so often.

I have been using Real player to play DVD's with SBS 3D content and with the demultiplexor it works fine splitting the video to two projectors

RealPlayer doesn't play Blu-ray though. I have all my Blu-ray's backed up in .iso form on my computer, so I need a 3D Blu ray player that works with the optoma boxes.


Update:
I still cannot get PowerDVD to work with the dual boxes. I have been using WinDVD which works fine, but still annoying to spend $70 on PowerDVD for nothing. Anyone else have any advice for this? Using PowerDVD with the Optoma boxes?

I'm getting ready to do the same thing and it should work in a similar fashion to yours as long as the chain is correct. Connect from your HTPC graphics card HDMI to the IN on AV reciever, then out from AV receiver into a HDMI multiplexer (splitter, etc but it must output the same signal that came in), e.g 1 in and 4 out. , so one goes into each port of each Optoma 3DXL and then I have another that goes back to my monitor on my computer. This way, the AVR is detected as the 3D device. I'm crossing my fingers that everything works this way. I'll try testing it out tonight. Oh and I'm using PowerDVD10. So, we'll see.

For my part, I decided to bypass the BluRay playback issue by converting my movies to the hard drive in Side by Side full resolution (3840x1080). This way I can open the video in any video player I want without being bothered by stupid HDCP restrictions. I have no idea if Cyberlink understands full resolution side by side videos but I think Stereoscopic Player can output that type of file to Hdmi frame packing through Nvidia 3DTV-Play or AMD HD3D.

At first I tried doing the conversion manually with free tools, but it's so difficult an annoying I did one movie and then gave up.
I bought DVD Fab BluRay 3D ripper and it's so much easier.
Edited by BlackShark - 7/17/12 at 12:10pm

Did you do side by side in a single file from dvd fab?

Yes, I do side by side in a single file at full resolution (the picture is 3840x1080).

The Epson 5010 is also flat polarized and can get a lot brighter than the JVC if you want a crazy big screen.

How can one tell which silver screen is better? I know there is the extinction ratio but manufactures say all kinds of things like contrast ratio but we know how that is. Any simple at home test with the small sample and just the glasses ans NO filters?

This isn't anywhere close to scientific, but if you have two pairs of glasses, shine a light through the left eye of one pair and look at the test sample reflection first with the left eye of the second pair and then the right eye of the second pair. You can repeat using the right eye lens of the first pair but results should be near identical.

The greater the difference, the greater the extinction ratio (which isn't the same thing as the contrast ratio). Scientifically, you would actually measure the two reflection values and take the ratio to get the extinction ratio.

This works with both linear and circular glasses, but you can expect a higher ratio with linear filters.

(tried to upload a graphic to illustrate this but the new forum uploader isn't working for me).
Edited by RBTO - 7/22/12 at 1:22pm

So I got a replacement for my Epson 5010. My old one works but has startup issues so I thought since I have two it was time to try passive 3D. I dug my Harkness 3D screen out of the closet where it has sat for 6 years. I just hung it up on a line with clips, like a drape and taped my polarizers on the projectors. So, the screen was terrible. From my 7' seating distance the screen structure was obnoxious. It was also pretty wrinked. I am sure a while being tensioned instead of just hanging would help, but I am pretty sure I did permanent damage by leaving it so long. It would be better from a further seating distance I am sure. I didn't think the extinction ratio was good enough, but in testing it looked really good. Playing a little World of Warcraft in passive 3D was amazing. The Epson 5010 is one of the best active 3D machines out, but passive was clearly a million times better. There was no eye strain at all, and my nose appreciated the super light glasses. I just used linear filters since I didn't want to spend the extra on half wave plates, but the brightness with the epson was fine, and I was in it's dimmest mode with the lamp on low, and 1800 hours on one lamp.
I wish I had thought ahead to get Motormans kit to try out. I am sure the epson has the power for that. Sadly though, my replacement projector started shutting down due to temp. It was on the better end of the dual projectors (I had them side by side) I am worried my replacement projector is worse than the one it is replacing.
So in the end I really want passive, but not with this screen. I am sure a new one would be fine from a further distance, but I really think if I am going polarized I will look at the new Silverstar curved screen. I will certainly try motorman's kit first though.