My Passive polarised Dual-projector setup

[relaxman]

I tried many mpeg2 decoders, "gabest" seems the lowest cpu usage with best deinterlacing.
I also tried ffdshow, powerdvd codec, etc. The problem is not here.
I don't know it i convert my videos to 2 x264 file, the hardware accelerating would work on two streams in Stereoscopic player? Has anybody some good experience?

[Likay]

I have only experience of dual streams since a few years back. I recall i had quite some amount of one-frame-lag while single stereofiles played well. I used stereoscopic player but there are big chances that it's upgraded to minimize such effects.

[BlackShark]

Every time I tried hardware acceleration for my videos, it failed miserably or produced artefacts.
I've got a powerful quad core CPU that can manage dual 1080p H264 video, i'll just stick with it and suggest everyone to do the same.
Spend 10 minutes installing the codecs properly and save hours trying desperately to troubleshoot problems with hardware.

[relaxman]

"Every time I tried hardware acceleration for my videos, it failed miserably or produced
artefacts."
Yes, exactly! Stereoscopic player doesn't like hardware accelerated codec (dvxa and cuda).

Now it seems, our problems is also gone with 3.2Ghz E6700 CPU and
Stereoscopic player "Do not use directx exclusive mode" option.
Today i watched 2 hours footage (2xHDV 1080i with bob deinterlace) and
i get no tearing, no artifacts and cpu is always below 70%.
For 3840x1080 mkv-s cpu is about 40-50%
All this with a passive Ati 5450 on xp.

[yunti]

I'm considering a dual projector setup but worried about the sync issues mentioned in the first post.

1)Is this still an issue?
2)Is it an issue for both AMD cards and Nvidia (I currently have AMD 5870 but will change to what ever works)?
3)Does it mean that only films will work (via eg stereoscopic player) and not games?
4) I play virtually all my games via Steam - will these have the sync issue too?

[BlackShark]

The sync issues are still there when the projector are left running independently, however it is not systematic, sometimes they run in sync and sometimes they jump in and out of sync. I varies a lot according to the games and the framerate. It seems that when the game runs into the V-sync framerate limit, the extra available time allows the two images to be sent at the same time. Again this is not systematic, sometimes it works well, sometimes it just refuses to work.

For uncompromised gameplay, I'm still waiting for the side-by-side "not squashed" output promised by iZ3D which would allow playing with display grouping with the correct aspect ratio and solve one of the last major issues of the system (the last one being BluRay3D playback without having to RIP and re-encode the movie).
At the moment I can only play 2 games with display grouping : TrackMania and Audiosurf, all the other applications I have just render stretched 32:9.

One more thing : I previously couldn't activate the 24Hz mode when using display grouping (i had a major GPU driver crash), I just tried again with the latest AMD catalyst driver and it now works fine. I enjoyed watching my first movie in native 24Hz mode. Camera pans do indeed look smoother but it's not a big difference ; I think I am used to jittery content from games and am not that bothered to see jitter when watching movies.

[tritosine5G]

wow

ICC color management

http://voxelium.wordpress.com/2010/09/2 ... me-cinema/

This sounds total awesome with infinitec filters , no ? GPU color LUT... sorry for OFF theres no dolby3d topic

[yunti]

@BlackShark Thanks for the reply. That is incredibly frustrating that the games don't work properly.

I reread your comment on the first post (as it's not easy to digest at first exactly what is happening with the stretching etc of incompatible games). From what I understand it seems that the you are effectively getting the compressed side by side format for 1080'p' as per the HDMI 1.4a spec? As the IZ3d driver compresses the full 1080X3960 to this. (is that correct?). Does Tridef have the same issue?

You mentioned that it sometimes works when not in eyefinity mode (ie not 1080x3960) but as independent screens. Does it stay in sync for particular games etc.. or is it just completely random as far as you can tell? Have you tested with eg a frame counter to see if it always works if the card is rendering at least 120fps (ie 60 per screen) which should be above the vsync limit?

It's weird how I have heard the sync issue mentioned elsewhere. The old tom's hardware article didn't mention it: http://www.tomshardware.com/reviews/3d- ... 589-7.html" onclick="window.open(this.href);return false;
Not sure why they didn't seem to suffer the same issue? Have any other people with dual projector setups confirmed the issue.(ignore that just reread jack bauer's post)
(Is a dual projector setup impossible on an Nvidia card? Do they have the same issue if it's possible?)


I'm trying to work out the best 3d projector setup to go with and had thought about the JvC x3 (RS40) 3d projector, but when testing it, the dimness, being limited to 1080p@24HZ and that I find shutter glasses tiring are pushing me towards the dual projector setup.

Ideally it would be via the infinitec method (so I don't have to have a silver screen that isn't as good for 2d). But there isn't currently a method for doing the colour shifting for games. (without going for the very expensive infitec hardware box). The 3d-vip, 3d-theatre may do this but it looks like it will be limited to 1080p@24Hz. (http://www.3d-vip.com/" onclick="window.open(this.href);return false;). So it looks like the best option is dual polarised, however I presume any sync issues will be common to polarised and infitec setups (if it ever worked for games).

And tritosine that's a great find for MPC, that would certainly seem to make it easier to watch movies via the infitec approach. Would love to hear if anyone managed to get it working using this, (jack bauer?) (Edit: Can it apply different profiles to each half of the screen?)

[tritosine5G]

(so I don't have to have a silver screen that isn't as good for 2d).

http://www.nexnix.co.uk/3d/3d_projectio ... terial.php" onclick="window.open(this.href);return false;

maybe this RP is better than silver, not tried it, and I rather want retroreflective shutter. Maybe once when I have better dual optics method I'll try dual projection. Be sure to ask about shipping practices if you order something (want it rolled up).

[jackbauer]

Just to keep you updated. I am releasing all my stuff for Infitec/Dolby3D color correction:
http://www.avsforum.com/avs-vb/showthre ... st20051188
Sorry, still no gaming...

[Fredz]

Nice, thanks for the update. Did you happen to take pictures of the DDD calibration test with your new solution to compare it with your previous one or a polarized rig ?

[jackbauer]

Sorry I just dont know what you are refering to. Please link me.

But in any case:

Infitec color calibration is done manually (*). Taking a picture of the screen is of no use (at least with a regular camera).
Sensors are not adapted to take advantage of the comb-like wavelength filters and recorded colors are not the same as what you really see with your own eyes. I did the test.

(*)Doing the calibration manually doesn't mean it is not accurate.
Although you cannot pretend to tell the abolute value of a color with your eyes, most of the calibration step is done in a differential way:
- One image with no filter but dimmed to simulate filter attenuation (Color are absolutely correct)
- The other image with filter. The only thing you have to do manually is make up for the color difference.

Even professionals do the calibration manually:
http://www.avsforum.com/avs-vb/showthre ... st19504307

I am not sure I answered your question...

Jack

[BlackShark]

I think he meant the DDD alignment picture (although most people use it as a crosstalk test).

[jackbauer]

OK. I didnt do the DDD test.

My new filters give slightly better results as far as ghosting is concerned. Less than I expected. But my ultimate goal was to get flat filters in order to integrate them right inside the projectors.

These filters are still outside the projectors at the moment so I have slight color shifts in the corners (thus wavelength shifts), and ghosting is likely to show up there.

Although ghosting has never been an issue with infitec, I did some testing. Instead of the DDD test, I used a vernier scale of my own to quantify ghosting with numbers:
http://img337.imageshack.us/i/ghostingtesthalfsbs.jpg
I remember I got less than 2 in the corners and about 1 in the middle of the screen with the old filters coming from dismantled glasses (I use an improved version of the patterns that I can move around to reach the corners).

(It has to be said that color correction has no impact on ghosting)

I will test the new filters and try to make photos.

Jack

[Fredz]

Ok, it would be nice to be able to see that DDD ghosting test with your new filters. For now that's the only method which allows anyone to compare ghosting between 3D solutions, and the resulting images have been quite conform to the appreciation of viewers.

[jackbauer]

OK, here you are:

NO color correction.

Without the glasses:


Through Left and Right lenses:
...
There is slight ghosting in the hi-contrasted center pattern.
Also, as I said, I am getting slight ghosting in the corners.

If I move the image around to center the corner patterns, I have:
...
This time, I am getting ghosting on the "L" (which is now in a corner), less on the "R".

Although this is very acceptable, it will become much better when the filters are inside the projectors.
1. Light beam will always be perpendicular to filter
2. Filter will be sitting between the lamp and the panels

Infitec claims that extinction ratio be around 1000 in theory.

Jack

[AntiCatalyst]

Mounting infitec inside a standard LCD projector seems like a bad idea, because they aren't really filters, they are dichroic mirrors. All of the light that doesn't pass through it gets reflected right back to the LCD panels, which are very easily damaged by heat.

I'd suggest turning on either low lamp mode or high altitude mode.
EDIT; or come to think of it, low lamp mode would turn the fans down, so that's a no go too.

[jackbauer]

Mounting infitec inside a standard LCD projector seems like a bad idea, because they aren't really filters, they are dichroic mirrors. All of the light that doesn't pass through it gets reflected right back to the LCD panels, which are very easily damaged by heat.

I'd suggest turning on either low lamp mode or high altitude mode.
EDIT; or come to think of it, low lamp mode would turn the fans down, so that's a no go too.

Please read again at the end:
2. Filter will be sitting between the lamp and the panels (that you cannot do with polars)

In fact between the IR dichroic and the panels. Thats what Infitec do, should you send your projectors to them for the mounting, as they suggest.
And the panels actually get LESS light. (BTW mines are SXRDs, not LCDs)

The lamp might be at risk though, but its only the lamp. Maybe give a slight angle to the filter (like the dichroic filter). A few degrees will prevent focusing too much on the lamp core.

[Fredz]

Thanks for the images jackbauer, that looks pretty good...

As you said on AVS it's better than a dual-rig polarisation system and I'd say it's at least equivalent to a Panasonic VT25. Not sure if it's as good as a DLP projector with active glasses (H5360 for example), but it's very close and higher resolution anyway (1080p with 2 x Sony VPL-HW15, right ?).

Might be the ultimate solution for projection of 3D movies if color correction can be done right. Why didn't you take photos with color correction btw, are there any problems when displaying a stereo image ?

Did you investigate real-time color correction with pixel shaders in 3D APIs like OpenGL or Direct3D ? Maybe that can be done in real time for S3D gaming ?

[jackbauer]

1080p with 2 x Sony VPL-HW15, right ?

Right

Might be the ultimate solution for projection of 3D movies if color correction can be done right. Why didn't you take photos with color correction btw, are there any problems when displaying a stereo image ?

Answer is 7 messages back! Camera sensors dont really comply with notch filtering. I'll try to take pictures trough glasses with/without color correction. See what comes from that.

Did you investigate real-time color correction with pixel shaders in 3D APIs like OpenGL or Direct3D ? Maybe that can be done in real time for S3D gaming ?

No I didnt. I am no programmer and this is beyond my skills. Also I am no gamer and OpenGL/Direct3D is an unknown world.
Color correction cannot apply to gaming the way it is done (AVS script). But the answer to that issue seems so close... Using lookup tables is so simple that its a shame iz3d programmers (for example) have not looked at the subject yet.

[Fredz]

Answer is 7 messages back! Camera sensors dont really comply with notch filtering. I'll try to take pictures trough glasses with/without color correction. See what comes from that.

Ah ok, sorry, I didn't understand your message when I read it the first time. I don't understand why we should see color differences between a photo of an image instead of looking directly at the image, but I'd be curious to see a picture of that anyway.

No I didnt. I am no programmer and this is beyond my skills. Also I am no gamer and OpenGL/Direct3D is an unknown world.
Color correction cannot apply to gaming the way it is done (AVS script). But the answer to that issue seems so close... Using lookup tables is so simple that its a shame iz3d programmers (for example) have not looked at the subject yet.

Maybe they are simply not aware of the existence of such setups, did you contact them about that ?

[AntiCatalyst]

Mounting infitec inside a standard LCD projector seems like a bad idea, because they aren't really filters, they are dichroic mirrors. All of the light that doesn't pass through it gets reflected right back to the LCD panels, which are very easily damaged by heat.

I'd suggest turning on either low lamp mode or high altitude mode.
EDIT; or come to think of it, low lamp mode would turn the fans down, so that's a no go too.

Please read again at the end:
2. Filter will be sitting between the lamp and the panels (that you cannot do with polars)

In fact between the IR dichroic and the panels. Thats what Infitec do, should you send your projectors to them for the mounting, as they suggest.
And the panels actually get LESS light. (BTW mines are SXRDs, not LCDs)

The lamp might be at risk though, but its only the lamp. Maybe give a slight angle to the filter (like the dichroic filter). A few degrees will prevent focusing too much on the lamp core.

whoops, my bad

[jackbauer]

I don't understand why we should see color differences between a photo of an image instead of looking directly at the image, but I'd be curious to see a picture of that anyway.

Take RED for example. When filtered, you get R1 and R2 which are different wavelenght notches.
If a camera sensor is well built, it will have the same response as the average human eye for RED.
That doest not mean the response will be the same for R1 (ou R2) alone... They are not designed to take care of that.

More pictures:
I emphasised RED because this IS the color UHP lamps have issues with.

Source as is (capture):


Source with correction applied (capture):


Screen with no correction (photo):

It is much worse than that with my own eyes (and other's). Should be the same (reverted) as the previous one).

Screen with correction (photo):

Colors look exactly the same with my eyes. Red/blue are the same. Not here. Camera definitely does show different colors than human eye

Maybe they are simply not aware of the existence of such setups, did you contact them about that ?

I am not really involved in this as I do not play games. My present setup is perfect for me. No judder, no frame lag, no tearing, no ghosting. What else? (Nespresso??)
I posted a message here for them: http://forum.iz3d.com/viewtopic.php?t=1 ... c&start=43" onclick="window.open(this.href);return false;
But you, gamers, should wake them up!

Jack

[Likay]

Hi jackbauer!
I'm following this thread with great interest and i'm interested in getting a "starter" kit for infitec and still some of my curiosity. For now i have an ageing dual projection rig using linear polarization with stereopolfilters + lcd-projectors which practically leaves nothing more than extra resolution to wish for. There are a few swedish resellers of dolby 3d equipment and i'm pretty certain i can get the necessary stuffs there.
A question: I plan just to get two pairs of dolby glasses to use as filters for a start (i've heard the aperture is small though). inspite of that, will these to some degree show what to expect finally?
I have two 3-lcd-panel projectors and if successful with the glasses test i think i can mod these (devilish idea with good chance of permanent failure... ) by replacing the internal original mirrors with infitec dichroic ones if they have such stuffs. 3 mirrors will be needed for each pj in that case and i have no idea yet of the eventual (probably too much) cost for this.

[jackbauer]

A question: I plan just to get two pairs of dolby glasses to use as filters for a start (i've heard the aperture is small though). inspite of that, will these to some degree show what to expect finally?

Hello Likay,

Two pairs of glasses will be enough for you to to start with. My present setup uses flat filters from Dolby but I see very little difference compared to my previous setup with lenses from glasses. It is a little better in the corners as I have very short throw projectors (1.5:1).

History of my setups:
Linear polars => Dolby from glasses => Dolby flat filters


In case #2, the aperture of the lens is wide enough to let the full beam go through, but a little wider would have been better in my case (short throw). Thats one of the reasons why I ordered real flat filters.

Opening in plastic frame: 38 x 32 mm


With this setup you will have everything to make your decision. If you want to play videos, download my LUT tables and try them. If you are using standard UHP lamps, they would work well. If not, you can play with my calibration routines to make your own tables.

I have two 3-lcd-panel projectors and if successful with the glasses test i think i can mod these (devilish idea with good chance of permanent failure... ) by replacing the internal original mirrors with infitec dichroic ones if they have such stuffs. 3 mirrors will be needed for each pj in that case and i have no idea yet of the eventual (probably too much) cost for this.

Cost: A set of two flat filters (left and right) is listed at 320$ (Dolby Price List).

Would have been a good idea but...
Remember that an interference filter is a glass plate with several (~50) vacuum deposited layers. Spacing beetween layers is critical as this spacing defines which wavelength go through and which is reflected. If the beam angle is not 90 degrees, spacing increases, shifting the values. 10 degrees is enough to let crosstalk appear. Aren't the mirrors in a LCD projector 45 degrees ?

The best place to put the filter inside a projector is between the IR dichroic filter and the block of panels (before/after the fresnel lens I dont know).

Bad news for me: I just happened to open one of my projectors this afternoon.

Everything is pack up very tight and there is absolutely no room available to insert the filter, unless I take apart everything, that I do not want. I dont want to disassemble/reassemble the whole thing and say: Hey, I have those 2 screws left.... )


Too bad one can see 2 slits (one vertical, one horizontal), but I think they are here for air flowing, not for possible filters.
I thought of putting the filter in the lamp itself, building some kind of sliders to set the filter IN/OUT. That would have been smart, as this would not have impaired the projector's waranty. But:

1. In my case, they are smaller (50x50mm) than the lamp opening (60x55mm)
2. As they are highly reflective, they should not be put before the IR dichroic filter which belong to the projector.
So my filters will stay outside. One thing I could do is moving the setup farther away from the screen and zoom less. We'll see...

The lamp compartment, the lamp and the IR filter (angled). Right behind, we can see the fresnell lens.

[Likay]

A question: I plan just to get two pairs of dolby glasses to use as filters for a start (i've heard the aperture is small though). inspite of that, will these to some degree show what to expect finally?

Hello Likay,

Two pairs of glasses will be enough for you to to start with. My present setup uses flat filters from Dolby but I see very little difference compared to my previous setup with lenses from glasses. It is a little better in the corners as I have very short throw projectors (1.5:1).

Thank you! I plan to use it initially as experiment and this is good news!

I have two 3-lcd-panel projectors and if successful with the glasses test i think i can mod these (devilish idea with good chance of permanent failure... ) by replacing the internal original mirrors with infitec dichroic ones if they have such stuffs. 3 mirrors will be needed for each pj in that case and i have no idea yet of the eventual (probably too much) cost for this.

Cost: A set of two flat filters (left and right) is listed at 320$ (Dolby Price List).

Would have been a good idea but...
Remember that an interference filter is a glass plate with several (~50) vacuum deposited layers. Spacing beetween layers is critical as this spacing defines which wavelength go through and which is reflected. If the beam angle is not 90 degrees, spacing increases, shifting the values. 10 degrees is enough to let crosstalk appear. Aren't the mirrors in a LCD projector 45 degrees ?

Yes they are but if somewhat successful with the glasses i plan to exchange the internal dichroic mirrors of the lcd instead of adding an extra filter! I made some loose studies about the 3-lcd principle and hopefully infitec has dichroic mirrors especially for 3-lcd's. I know they modify some existing projectors but not which types or how.
The mirrors in 3-lcd's are dichroic and maybe the extra filtering of the infitec glasses will cause a very high basecolor lightloss with some basecolors vs l/r-lenses. I have no idea how "narrow" the original dichroic filters in the lcd's are for now but it may cause some trouble...
I probably typed an error in previous post about needing 3 mirrors/pj. Two mirrors with infitec specs seems needed for each pj. The mirrors should be a tad cheaper than standard infitec/dolby filters since they do not have so many "active" layers but that's just a very uneducated guess... I'm not sure dolby sells those mirrors either and if they do i assume alignment might be very critical! If possible to get a hold of those mirrors one big plus is that the basic colors of the projectors are entirely replaced and the brightness should theoretically be the same as is now! Maybe metamerism between people will be reduced as well?

Everything is pack up very tight and there is absolutely no room available to insert the filter, unless I take apart everything, that I do not want. I dont want to disassemble/reassemble the whole thing and say: Hey, I have those 2 screws left.... )

Getting two screws as leftovers is not the worst thing that can happen... I'm certainly not determined to make such a mod to my pj's yet. Even if they're old they're deared but if i want to change the mirrors i need to take everything apart thus really risqueing the functionality of the pjs without possibility to restore them...

One thing I could do is moving the setup farther away from the screen and zoom less. We'll see...

If you have the space, definitely!


For my concern this could fall on many things. Maybe i'll try to get a hold of a cheap 3-lcd-pj with a broken lamp just for pre-tests.

Cheers!

[jackbauer]

I probably typed an error in previous post about needing 3 mirrors/pj. Two mirrors with infitec specs seems needed for each pj.

OK. LCD can use only 2 dichroic mirrors. But with Infitec, I am afraid you will actually need three of them:

Lets assume each color spectrum is divided in two: R=R1+R2 / G=G1+G2 / B=B1+B2

Assume projector #1:
R panel: R1 goes through, the others are reflected.
G panel: G1 reflected, the others go through.
That leaves R2 + G2 + B1 + B2. If you want only B1 to reach B panel, you must use a third dichroic mirror.

Also this mirror must not have a solid back. R2+G2+B2 must fall in a lumen trap. Never used.

To avoid crosstalk between the two projectors, you also need gaps between wavelength notches. You lose about 60% of the light overall.

The mirrors should be a tad cheaper than standard infitec/dolby filters since they do not have so many "active" layers but that's just a very uneducated guess...

Crosstalk requirement will not allow this. Notch edges must be steep and you will need gaps.

If possible to get a hold of those mirrors one big plus is that the basic colors of the projectors are entirely replaced and the brightness should theoretically be the same as is now!

Sorry Likay, 40% at best. R2 G2 B2 and gaps are definitely lost.

IMO, it should be better to use a single Infitec filter between the lamp and the first miror. You may lose an extra 5-10% light but it should be much simpler.

An idea:
Putting the filter in the lamp itself should be possible...

EDIT:
Interesting explanation/warnings about UHP lamps: http://www.ercservice.com/lamps/philips ... Lamps.html
...where you can read: UHP lamps are not good toys for casual experimenters. I agree.

Too bad. So I give up. Filters will stay outside ! Still much better than polars anyway.

Jack

[jackbauer]

Please find my Infitec/dolby color correction software kit version2:
http://jptheking.free.fr/3d/Dolby_calib ... kit-v2.zip

This of course is only for playing 3D movies. No gaming.
Jack

EDIT: Documentation can be found here: http://jptheking.free.fr/3d/Dolby_calibration_kit.doc

[jackbauer]

Likay, have a look:
http://www.avsforum.com/avs-vb/showthre ... st20269971" onclick="window.open(this.href);return false;

[Likay]

Thanks. I've got the filters quite some time ago but i lack the time to try it out properly yet (the drop-in of 3ds takes some of the freetime i have too... lol).
Much work but money drops in and very little time to spend them...

[hciputra]

Great thread, with regards to tearing due to Nvidia non existant horizontal span mode in Win7, wonder if anyone have used this before http://www.dhgate.com/mviewer-mv103-hdv ... 3759f.html" onclick="window.open(this.href);return false;
basically it does the spanning work, the box is tricking the OS to think that it is a very high resolution monitor which then split into 2. Maybe it will help in gaming too? Matrox have a box like this too DualHead2Go, but i think this Mviewer is superior as it uses dual link DVI input instead of VGA in the matrox

Regards

[BlackShark]

I think Matrox also has a DVI dual link version and a DisplayPort of the dual-head2go. But it's still an extra purchase.

By the way, iZ3D has introduced a side-by-side span mode in the latest iZ3D beta driver designed to leverage AMD Eyefinity span mode.
The feature is hidden in the config.xml file and is not documented yet. In some games, it works great, it other games it's buggy or fails to render, it's still a beta feature but at least it's there !

I've been able to play UT3 and Devil May Cry 4 with perfect sync. It's so good on the big screen !
http://forum.iz3d.com/viewtopic.php?p=30005#30005" onclick="window.open(this.href);return false;

[jackbauer]

I am actually using a matrox triplehead2go digital (dual link DVI required).

For video playing, it is the *only* answer I found to address the judder/tearing/sync issues. I can then use overlay and reclock. I am using 48fps as I am doing frame interpolation as well.

If you can do that with the graphic card settings, then there is no problem for you. I have never been able to achieve that on my side with 7 different entry level graphic cards (I am no player) including ATI, NVIDIA and MATROX. To speak truly, I have not tested Vista, Seven (I am an XP guy) and high range graphic cards. Mine is an ATI Radeon HD 3400 (no need for more).

Jack

[relaxman]

XP has issues with dual screen directx acceleration.
Only one is hw. accelerated, so this is why delay, tearing occurs.
This is fixed in vista/w7.

But despite this i have great success in XP with Ati 5450 and extended display mode. No tearing and no sync issue. I will test the 48 fps, but our movie is in 50i format, so we see 50fps right now

[BlackShark]

I do not have any 50p footage, but on my setup I can configure the desktop to run in 24Hz, 50Hz or 60Hz in eyefinity mode. No sync or tearing issues here.
I did try 24p footage though, and the difference in judder is noticeable (and noticed my MediaplayerClassic's playback statistics)

After a week of testing the hidden iZ3D side by side "span" mode.
There's a good reason why it's hidden : it's still very buggy.
There are very few games that run 100% perfect, the main issues are usually mouse pointer related and a difference in aspect ratio between 2D elements (hud, menu interface, etc...) and 3D elements (the rest of the game). However most games are playable and display with perfect sync, which is great !
My only real disappointment is that all Source-engine based games (HL2, Left4Dead, Portal 2,...) show a black screen ingame, and therefore are unplayable on the dual-projector.
I have high hopes that the situation will improve if iZ3D keep working on it and be as useable as any other output.