The Ultimate 3D projection system: A Practical Discussion Thread - Page 48

So back on topic so to speak. for the ultimate 3D passive system aside from the filter tech what is the setup ?

1. HDMI demux box or PC / HTPC ?
2. a pair of 1080p native DLP or LCD, 3LCD, LcOS/D-ILA ?
3. Gain screen or not ? ( black diamond ? )

ive been thinking of getting either two optoma HD20 or Epson 8350's and fabricating a portable rack that includes either the PC of a demux box. I appreciate your ideas and thoughts .

A demux box I think would be the best for most. It makes it easy to just hookup a bluray player

Htpc are still mostly a hobby for people.

Of all of the home theater owners I know, I would venture to say that only 1 in 5 have a HTPC. Most want a simple solution that integrates with their already existing equipment such as blu ray players and AVRs. I think you want to still provide HTPC capability, but the demux solution will open up your base to a larger group of people.

One question I have is how does someone revert to a single projector solution for 2d?

I am a PC user, It's the most flexible solution, however I can see clearly as day that current PC with dual-out is far from ideal : ergonomics are horrible, and there will be compatibility problems as application developers embrace Nvidia and AMD standardized 3D outputs (3DTV play and HD3D) which only support official 3D outputs Hdmi 1.4 and DisplayPort, and Windows 8 will make it even easier for developers by unifying these into a univesal DirectX 3D output.

As much as I love my current setup, I am eagerly waiting for a good demux box.
However the requirements on that box differs depending on what usage is expected.
Most people will consider hdmi1.4a enough since they watch BluRay, some TV broadcasts and games on PS3 or Xbox360.
PC users wouldn't be satisfied by that : PC users like myself want FullHD at 60Hz per eye.
At the moment Nvidia 3D Vision is leading the market with their proprietary DVI Dual-link system, but it isn't ideal since AMD does not support it as they prefer to use DisplayPort 1.2 or Hdmi @ 3GHz. The ultimate system needs to be compatible with everything.
Luckily, Nvidia's brand new graphics card claims to support both Hdmi @ 3GHz and DisplayPort 1.2, they haven't updated their official list of supported devices yet for 3D, but at least the hardware has what's required, so a universal solution is now within reach.

The ultimate demux box should then be compatible with Hdmi1.4 @3GHz, that's a minimum.
I however have some doubts about how many inputs the box should have. The main problem is how do you connect a PC and other sources (external BluRay player, TV set top box, game console) to this one demuxer.

I do not have an AV receiver yet (I'm planning this for some time this year) but I know that AV receivers are currently designed for Hdmi1.4 minimum specs and would not support 3GHz input. So you'd need two inputs on the demux box, just to make sure the thing is usable by both a PC and all the other home 3D devices through current AV receivers.
An other issue is surround sound with these receivers, how do you get the sound from the PC to the receiver while it's on a separate hdmi link.
The Hdmi audio return channel isn't supposed to transfer all audio channels, I don't think receivers would support 5.1/7.1 through the return channel.
All current Hdmi 3GHz graphics cards have only one Hdmi ouput, so you have to split the audio and video through one of these ways :
-use Hdmi for video and optical out for audio
-use DisplayPort for Video and you have the choice between Hdmi or optical out for audio

The easy way out is to use optical audio out, and then the user has more choices for video out (Hdmi or DisplayPort), because I am almost sure it would work but wouldn't be "ultimate" for BluRay movies but it doesn't change anything for PC games (since game audio is generated in real time)
The "ultimate" way would probably be to use hdmi for audio but I do not know if Display Port and Hdmi work simultaneously when playing protected BluRays, the HDCP protection scheme might cause trouble.

Anyways, back to the original question : What types of inputs the demux box needs : I reckon at least one Hdmi1.4@3GHz is mandatory, for PC uses and for future-proofing possible home systems upgrades.

A nice addition would be a 2-input hdmi switch so that we can plug both the PC and an AV receiver at the same time, however we could probably use a separate switch for that so it's not that important.
A nicer option for this secondary input would be to have DisplayPort 1.2 input so that PC users can have more choices (Hdmi or DisplayPort)


My current solution for this is to clone video outputs and manually switch off one of the projectors.


#2 doesn't have a unique answer, it depends on many factors like RBE sensitivity, usage for games or not, and most importantly : money.
#3 A white matte screen is the ultimate goal. There's a money factor in it though since it requires brighter projectors, which are expensive. High gain screens also have some fans for the light boost and for parasite light rejection. BlackDiamond claims to provide the best of both worlds but it's EXTREMELY expensive, it has it's fans though (see the BlackDiamond thread in the screens section)

Hi. Believe that this splitter is good to divide the 3D signal into two? From blu ray 3D player to the two units OPTOMA 3d-xl.

http://www.ebay.co.uk/itm/Cablesson-...item56483fe5c1

And when you do, how do you avoid uneven lamp decay? I have to say, I've seen the SIM2 DUO system (two Lumis projectors with Infotech), and while the 3D was superb, it was no better than a single Lumis SOLO with triple flash. One hi-performance 3Dprojector seems so much more sensible than going to all the trouble of properly aligning and calibrating two lesser projectors and fiddling with filters...not to mention dealing with the intrusive presence of stacked projectors (if, like the majority of homeowners, you don't have a separate projection room). There were two key words in the title of this thread: "Ultimate" and "Practical". I think postings over the past few weeks have ignored the latter and have drifted into a dialogue better suited for the Geekologie blog.

Outside of DLP every other technology used for 3D introduces some "ghosting". If you're not particularly bothered by this then who cares. DLP is limited when it comes to black level. It will be interesting to see how the dual system stacks up -- for example a dual system Epson 9500 and 7500 with active DI and FI for 3D vs. the Epson 6010 with no active DI or FI for 3D. I 'm hoping to find out soon (filters ordered and two Optoma 3D-XL boxes sitting here waiting -- my 6010 is ready for the comparison).

to revert to 2d is simple just turn off one projector ( turn off the right ) and flip the filter out of the way. i just turn off the 3d view in the stereoscopic player if its a 3d movie i want to see in 2d and if its a 2d video i can use several players on the pc.

I agree that one projector would actually be the ultimate. to really be a hot item to a mass market it should be a unit like the sim2 duo. that is very high priced. i know its possible to make someting like that way more cost effective but finding a manufacturer interested in doing so is not easy. the LG passive CF3D could use the omega filters, but 10k + ? it could be done closer to 6k even with high end 3 chip LcOS. one could take two jvc RS40's un case them and with the right beam combiner create such a unit. intergrate a demux in the box and you have it.
done well in a nice package would be Practical and high performing.

ghosting is only a result of the filtering tech and shouldnt be due to the type of projector. i agree the black levels are best with units like D-ila and sxrd or 3 chip DLP. i really look forward to your results

IMO and a lot of others ghosting is a problem with the tech. Go to the RS-45, W7000, HW30 thread started by Zoombie. You will see photos showing the differences in ghosting between the different technologies (DLP vs. LCD vs. LCOS) -- DLP is by far the best!

I read through about 25 pages of this thread and still cant determine whether you all have found a screen that performs really well with this type of setup.

What are the top performers that have been tested so far?

im sure that those test show some ghosting. its due to the filtering technolgy. after spending over three years developing and refining the omega 3d system ( panavision 3d ) and doing many heads up tests with all other technology out there in cinemas and special screening rooms its the filters. if each eye filter has enough rejection of the other eye's image there can be no ghosting unless the content is flawed. off angle performance of most 3d stereoscopic systems loses rejection even mine. but the differance with the omega 3d is the on axis rejection of the other eye is way over 1000:1 and worst case on edge is ~80:1 most ideal polorizing systems are ~200:1 on axis at best and fall off to nearly 10:1 in some cases off axis.
i will look at those threads more closely. having tested 3d on sony 4k cinema systems, 3dlp chip barco and christie, film and a new nec i would imagine there would be ideal matches for polorizing systems. dielectric multiband 3d systems that dont need a silver screen to preserve some of the polorization do not really show a differance with tyoe of projector as far as ghosting is concerned. not trying to argue just i have spent way too much time on stereoscopic projection maybe lol

if your going with a polorizing setup the screen matters. with the omega 3d system as with the dolby/infitech 3d you just need a good white screen of any kind. i havent listed screen types ive used but i will find some info.
by using a passive system with multiband filter tech you could use a decent white wall for all it matters. wont be as ideal as a nice matt white screen but silver screens have hot spotting, some more than others.

Yes you are right, but in a dual projection system the tech has nothing to do with ghosting, it is all about the filters. JVC is one of the worst with ghosting, but when you stack two of them and use filters I doubt you can see any.

Yes, and that's why I hoping the Omega filter system with dual projectors works better (less ghosting) than any single 3D projector other than a DLP and maybe as good as DLP.


Take a look at the differences in ghosting between the technologies shown by the photos in the link below (single 3D projectors).

http://www.avsforum.com/avs-vb/showthread.php?t=1382091

Those aren't different technologies though. They are ALL active shutter glasses. You are comparing apples to matchsticks. The Omega system is a filter, something like a polarizing filter. It is not affected by anything that causes ghosting on those projectors in that review. All that ghosting is related to image switching speed. In a dual projector system there is no image switching. One projector is always showing one eye's view, the other projector the other eye. Ghosting in the Omega system has everything to do with the filters, and nothing to do with the projector and its type(dlp/lcos/lcd).
Polarized is much the same, but it's ghosing is mostly affected by the quality of the polarizing screen.

1) demux for sure. I have both and will never use the HTPC for watching movies again. The software is too buggy.

2) Lens shift is pretty much a requirement. Also brightness is vital. I really think a 2k lumen projector should be a target. If we are talking higher end, I would go with two Panasonic 7000's (or if you aren't a gamer the Epson 5010). On the lower end, but with better brightness the Panny AR 100 looks like an amazing deal.

3) Gain. I like a bright image so I would go with a higher gain screen. The brighter projectors you use the less gain you need. On the other hand any of the projectors I mentioned have much dimmer modes than their brights so if you have a high gain screen you can run eco mode and still be plenty bright. With my high gain Vutec Silverstar I can do 3D on my epson in 3D Cinema mode and not have to switch to 3D Dynamic which is too loud for me. A normal gain screen and I would have no choice.

This is all very personal of course.

Exactly! The technology shouldn't matter with a dual LCD 3D system with the Omega filters. A single LCD 3D projector or single LCoS projector like the Epson 5010 or JVC RS-45 projecters have ghosting issues, but by using two projectors with the Omega filters you bypass their "switching" limitations.

Does anyone know if the 3d-xl's introduce any additional input lag?

You can also bypass switching limitations (and considerable kludge) by just using a single active 3D DLP projector with 120Hz switching. Again...satisfying the qualifier of being "Practical". The images you shared of the W7000 certainly looked watchable...no ghosting. If you wanted to push more toward the "Ultimate" (where price is less of a factor), you could just go up market to a higher performing active 3D DLP projector from manufactures like DPI, SIM2, etc.

I have been told in the 3DXL thread that they do not. No one ran an objective test, however.

Not that this is entirely helpful, but I have a Monoprice 2D->3D convertor that adds <1ms lag. So it's possible to add an interim device like that and not pick up any lag to speak of.

im not sure that practical is going to mean best performing 3d. certainly a lot of home users will opt for an lcd flat pannel tv with active glasses and deem it most practical for getting 3d in the home. a passive system can have a far better image. a lot of people dont like active glasses and get tired of watching 3d with them. a lot of people have never seen a 3d system that has no ghosting at all and until its seen heads up to the other systems you dont know what your missing.

Active 3D isn't even close to ultimate. In a perfect active system (which none are close) each eye is staring at black half the time. In real ones you stare at black 75% of the time.
Now the real ultimate system would use something like the Omega filters to split a single bulb's light and run through two lcos/dlp chips and out through a single lens.

I can't vouch for the omega filters (yet), but I think we are lucky to have 3D moving forward at all with all the terrible 3D tech out there. I have owned a number of 3d lcd's/plasmas/projectors etc. Many (most??)displays/glasses combo's don't do 3D any justice at all unfortunately.

I have a couple of questions that perhap Rob on someone else knows the answer.

I have seen references on the web that IMAX uses the 45/135 orientation for their polarization with the 45 deg. orientation being for the left image and 135 deg. orientation being for the right image. However, several sources of 3D glasses are selling the 0/90 version claiming it is as used by IMAX. Does IMAX use both setups (perhaps one for film IMAX 3D and the other for Digital IMAX 3D?) and when the 0/90 verion is used is the 0 deg. orientation for the left or the right image?

Also for RealD does the filter for the right image use right hand circular polarization and left hand circular polarization for the left image, or vice versa?

Thanks. I forgot about the 3d forum. I just stopped by that forum and there doesn't seem to be any lag discussion. I am going to see if someone can do an actual test.

You say that like it's a bad thing. The key is how much time that 'half-the-time' turns out to be. With 120 Hz (60Hz per eye), you are unlikely to see any ghosting or jitter. 144Hz (72 per eye) is even better. When you look up at a light in the ceiling that's operating at 60Hz, you don't normally see it flickering.The problem comes when a projector is not fast enough to switch at 120 or greater. As for your assertion that no active system is close to perfect, I'm not sure what you mean. No technology is perfect. Everything is a compromise. Clearly most projector manufactures have determined that active is more practical than passive...even those, unfortunately, who have switching speeds that are too slow to render a ghost-free image.

By not perfect I mean most of active systems out there you are staring at black 75% of the time. Doesn't matter how fast you switch, it is still 75% of the time. I realize with 120Hz you don't see obvious flicker, but it is there. This creates an eye strain (minor if you have tolerance,but still there) that passive doesn't. Another big factor is passive glasses are super light compared to active. I am sure that will improve over time, but it is a big factor now.
This is why they are making flat screen tv's passive now. Those TV's have to cut the vertical resolution in half, but it is worth it to get passive for some people. I wouldn't want to game on one of those but for living room use I found them quite nice.

I assume you are referring to blanking time. With slower technologies such as LCD you are typically seeing one scan period out of two and a glasses opening efficiency of 50%. This corresponds to a blanking time of 4.1ms over a frame period of 8.3ms. With DLP this reduces to 2ms over the same 8.3ms frame period...unless you are talking about LED/DLP, in which case you're looking at just .9ms. So I'm not clear where your 75% figure comes in. Fatigue and ghosting are a by product of cross talk...or a momentary display of both left and right images on the screen at the same time. This is more likely to be an issue in bang-for-the-buck LCD/LCOS projectors.