The Ultimate 3D projection system: A Practical Discussion Thread - Page 55

Does anyone know if the LG CF181D (which I believe is an LCoS projector) has all its colors polarized in the same fashion as the JVC's LCoS?

It is not, it uses sony SXRD panels.

http://www.lg.com/za/it-product/proj...ema-CF181D.jsp

says its a "SXRD system projector using LCoS, an innovation that has strengths and advantages of both DLP (high contrast ratio) and LCD (superb color impression) technology. With the high response time of 2.5ms, LCoS technology provides amazingly sharp and detailed picture quality even in scenes with fast motions."

as far as I know all SXRD have green at a different angle

I know that the Sony 4k cinema systems puts a quarter wave plate after the LCoS to make all colors circualr. its claimed that this re-captures energy

polorization is only relative to a surface or axis, you can have S or P plane polorization at any angle depending on what you referance is.

there are better ways of poarizing light than the absorbtive types

http://en.wikipedia.org/wiki/Polariz...ing_polarizers

this may have been posted before but its got some cool animation of polarizing

I finished my 3d system, though it doesn't quite belong in the $3000+ category. I have two barco reality sim 6 projectors with omega filters mounted internally. The omega system is amazing, absolutely no crosstalk, but I would love a little more brightness. Perhaps I will figure out a way to jury-rig a brighter light into the projector.

Does that mean if you use two projectors that have green at a different angle you could use quarter wave plates to make each projector circular without losing light?

Are LED chips polarized?

How bout this for a system

-LED chip from Luminus Devices
-2x DC4 DLP chips
-Omega Filters
-DynamicBlack Technology
-Compatible with A-lens

I could see Projection Design releasing something like this with a huge price tag, but I would rather see a company like BlackMagic build it with a realistic price.

Any thoughts or changes? Is it possible for the LEDs to be made to match the L/R filter, meaning you could use two LED sources and and barely lose any light? Anyway this could be built and sold for less than 5-7 thousand?

That looks great. im so glad it is working well for you. most cinema systems with 3D have upgraded bulbs to offset the losses mine is no acceptation, but with dual Barco's i imagine it looks fantastic. we had an install in India nearly just like yours.
the internal mounting is the best way to go, it minimizes angles thru the filter to yield the most uniform color and extiction.
thanks for posting the pics.
you know we can make custom sizes and even custom mounts for a small fee. im working to impress certain people to get to working with a projector manufacturer to get this filter system integrated into a consumer product.

Yes it dose. with the right parts you can change any polarization.well i should add you can in some cases and not lose any reasonable amount of light. wave plates lose very little

Rob maybe you can help out, I remember you saying you made your own filter similar to the JVC SPAR filters you have. If you used two LCD projectors that have different polarization alignment could you simply use wave plates to make each projector circular without having an additional linear sheet at 45 degrees?

I know this would cause more ghosting because your glasses could only be matched to Red and Blue angle but this might be a good way to do large screens on a budget.

For those that don't understand what I mean, even with circular polarization there is first a linear filter, so to minimize ghosting you make sure your glasses match the linear angle. Hold up two circular lens to a light and rotate them and you will see that at some point they will be darker, that is the angle you would want to mount the filters.

Slightly off topic, but does anyone have any experience upgrading bulbs. I can certainly get a 600 or 1000 watt 6500k metal halide or hps bulb, mount it in the case, and power it externally, but I assume one would need to fool the projector into thinking it still had a working bulb. We really do need high powered bulbs for these 3d rigs, it is amazing how much light each passive (and active) system eats up.

the Omega 3D kit is now also listed for LCD optomized projection filters.

http://www.ebay.com/itm/3D-by-Omega-...item231c730e33

the kits may change a little soon as we end the beta listings. custom kits are also possible as far as filter size, mounting and # of glasses.

I have never played with up sizing a bulb in home theater units, only cinema systems. i would worry about heat management of a larger bulb in a small box but it makes sense. the focus of the light into the light engine is important in order to keep all the extra light your putting in but anything is possible.

For those still doing passive polarized 3d what screen are you using and how is the 2D and 3D?
Also anyone have good success with circular 3d and no ghosting? Lastly, were did you buy your filters?

For those of us looking to exchange our current kit for the LCD kit what do we need to do?

message me with contact info. also tell me how the standard filters are working and what throw ratio is your setup using? im still collecting feedback to help offer better setup advise

your right in that if the green is offset at a different angle a single wave plate external would not fix things in an equal way. in the sxrd system the polarization is done right before the LCoS, if one could place the right wave plate after the green channel then you could orient it to match the others. but this would require getting inside the light engine.

Well I have decided to put together a passive dual projector setup for my dad's setup. We already have two LG CF181D projectors and I have just purchased the Omega Kit. At the moment we will be projecting on to just a white wall, but will hopefully be purchasing a screen soon enough. I have a couple quick questsions:

1. Will a geforce 440 gt support dual passive 3d?

2. Has anyone tried the omega system with a LCoS projector? How do the colors look?

3. How do the lenses mount to the projector? I have a feeling the mounting on the LG projectors might be tough.

Thanks for your help!


On a side note: is anyone willing to rent/lend out Avatar 3D Blu Ray? I am setting this system up for my Dad's birthday and would like to use Avatar to show it off (one of his favorite movies in 3D).

How soon do you need Avatar? I have a copy I will sell or rent out.

that would be awesome! I am setting this up for him next Friday/Saturday (May 4th/5th) and could send it back to you the following day.

Here's my problem. My Oppo, which has two HDMI outs (3D and supposedly forces 3D to the display even though the display is not 3D) will not send 3D to both Optoma 3D-XL boxes (only to one). I tried a HDMI splitter that's 3D capable and it won't send the signal to the Optoma boxes either since the displays are not 3D. Very frustrating. Is there anyone using a splitter to the Optoma boxes and getting a left 3D signal to one projector and a right to the other? If so, what splitter are you using? Anyone doing this with a 3D receiver that has 2 HDMI outs?

This brings me back to the question I was asking a year ago, but never got a satisfactory answer.

Why is green's polarity offset in the first place?!?

Both LCD and LCoS tech's use 3 colour chips and use dichroic mirrors to separate the light into colours and a trichroic prism to recombine the colours. Both kinds of colour chips are polarizing.

When I talked to some trichroic prism manufacturers, they said that the trichroic prism would reflect green (instead of pass it) if it wasn't 90degrees off of the other two. But they also said that they sell trichroic prisms that don't require the green offset, but they were more expensive. Like $10 instead of $5.

And what exactly is creating the offset? The light is unpolarized before hitting the green LCD panel, and it is polarized when it exits (enters?) the prism. The LCD chip itself will polarize the light. Is the vertical polarization coming from the chip? If so, that means that R & B LCD chips are of one kind (Horizontal polarity) and G chips are of another kind. Seems like that's a lot of work to avoid a $5 price increase in your prism.

Summary: Putting a wave plate in your Green light channel inside your projector would probably cause green to not transmit through the prism. The SPAR filters rotate G to match R & B by targeting its wavelengths.

1) should be good enough as far as I know. When you get it setup try World of Warcraft. It has built in 3D and is pretty impressive and free, but a huge download.
2) no idea.
3) There are pictures here of peoples mounts. I believe the OP uses a cereal box cut up and the filters taped to it.

I would add that a screen will make a big difference. I would at least go to a fabric store and get some blackout cloth. It is thick white material used to block light from windows. It makes a much better screen than a wall. I used it for a year or so. I also grabbed some black ribbon and made a border so it looked deliberate. It was like 16 bucks total.

the gforce 440 should work but i have not tried that one. in theory any good perfroming video card with the ability to run dual desktops should work with Tridef or Stereoscopic player.

make sure you ordered the LCD optomized Omega 3D kit. there is a separate listing for them. if not message me and ill make sure you get the right filters. the colors should look great especially if your throw ratio is not too short. ie 1.2:1

mounting them should not be hard. take a look back in this post and you can see a couple of good ways. the filter comes mounted on a plate with holes on the edge so you can just make a simple bracket and some #8 screws to hold the filter close to the lens. make sure the angle is perpendicular to the image beam for best results.

I've mounted mine on door hinges and mounted the whole lot on the racks where I place my projectors. you can see the pics. here:
http://www.avsforum.com/avs-vb/showt...280393&page=45

Motorman,

p.m. sent.

Cheers

[quote=motorman45;21945600]

make sure you ordered the LCD optomized Omega 3D kit. there is a separate listing for them. if not message me and ill make sure you get the right filters. the colors should look great especially if your throw ratio is not too short. ie 1.2:1

QUOTE]

thanks! I did purchase the LCD optomized kit. Can't wait to try this system out! Thanks for all your help!