3D projector using Infitec method? - Page 2

I did some measurements with lenses from some of the commercial Dolby Digital Cinema glasses that I was able to get ahold of and posted numbers on another forum, but figured some people here might be interested in them.

I used a Minolta LS-110 that measures light off the screen (a Da-Lite High Power) and all measurements are in cd/m2. One of the lenses lets light through that looks very green and one very red, so I'll call them by those colors (and refer to them as filters). My room was getting a little bit of light into it and with the projector blocked and no Dolby lens on the meter I was getting about .01 cd/m2 near the end.

Here is what I got for measurements with a 100 IRE full screen image with an Epson 9500UB:

No filters: 51.8
Green filter on projector: 33.9
Green filter on projector and green filter on meter: 26.9
Green filter on projector and red filter on meter: .23

Red filter on projector: 8.8
Red filter on projector and red filter on meter: 7.4
Red filter on projector and green filter on meter: .16

I should probably mention that when I first started doing the measurements my room was getting enough light in that I measured .11 with the projector blocked and it wasn't too long after that when I tried putting both filters over the projector and measured .23 off the screen with no filter on the meter. But I don't know if the room light had changed by then.

As far as total light loss with this projector with a UHP lamp it looks like it goes from 51.8 to 34.3 if both eyes are added, or 17.2 if both eyes are averaged. Or a 67% loss if using the average of both eyes.

Later I did some measurements of sunlight outside. Off a white piece of paper I measured.

No filter: 17500
Green filter: 3600
Red filter: 8200
Both filters: 56

BTW: I have the glasses and projectors, but no way run 3D to them. If anybody near Seattle wants to try a dual projector 3D system like this and has a PC or something else that they could bring to drive the correct signals to the 2 projectors, they would be very welcome to come over and try this out.

--Darin

Thanks for the numbers. When you say green and red, are you referring to the left and right lenses from the Dolby glasses? I thought they both appeared to be somewhat grey... is that not the case?

Yes.

I just tried them again on a white piece of paper outside and at what looks like the correct angle the light they throw onto the paper with the sun shining through them can look pretty gray. They are curved and toward the outside the image takes on more color or if I tilt them the resulting image has more color.

I originally started calling them green and red after using them on the Epson 9500. When I put them on the projector the image on the screen is very green for one of them and very red for the other. I haven't measured the color balance that way.

I noticed when I saw the $80k SIM2 setup that uses the Infitec system that one image was more green and one more red.

--Darin

Thanks for the measurements.

Something to take into account though: Make sure that your LS-110 has the exact same response as the typical human eye. For example, all the photos I took with a Canon Powershot A700 show a huge color shift on the benchmark I am using for color calibration. Although my eyes (and other's) do see correct colors when calibrated:
http://www.mtbs3d.com/phpbb/viewtopi...980c5&start=32

A light transmission of about 45% is what I get for both filters (115/255).

33.9/51.8 seems a little high, but 8.8/51.8 should be definitely wrong. That may depend upon the kind of lamp your projectors use. If they are typical UHPs, you should have about the same response as on mine.

As far as PC output is concerned, I just ordered a Matrox's M9120 graphic card which has two hardware overlays and extended desk capabilities, so that both outputs are in sync. That should prevent you from tearing and/or judder (I am using reclock). I'll keep you informed when I have the card.

EDIT: @darinp2: You may be fortunate enough to have a color correction device built in your projectors:
from : http://www.hometheatermag.com/frontp...lcd_projector/
...you can read: "A color management system, RGBCMY, provides Hue, Saturation, and Brightness controls for all primary and secondary colors (red, green, blue, cyan, magenta, and yellow). "

Hopefully this could be usable to correct dolby/infitec color shifts. This would give you control over the 8-vertex cube mentioned in my link (still not so good as the 27-vertex cube though).

Jack

We (no need to name names yet... ) plan to introduce a projection system similar to Infitec/Dolby within next few months, but using a different filtration system. The pricing would be lower than amounts mentioned earlier in this thread, about similar to low/middle priced high-end home 2D projectors. The quality is, taking into account individual projector's capabilities like light output, equivalent to what you see in cinema.

Color correction will be done on a PC, for a start, though this unfortunately would somewhat limit the functionality, and later using dedicated electronics box. Full HD, stereoscopic, would be supported in any case.

Would you consider buying such system? Is there some additional requirement you see as critical? Do you see as important that glasses will be without batteries (and priced lower than active glasses), and no polarized screen is needed?

Please note that you can't purchase anything yet. I would just like to hear more opinions to prepare a better product.

Can you explain what your "different filtration system" is? Is it based on color wavelength?

Pterodactyl,
The short answer to your question is: yes. The slightly longer answer is: depending on the quality.

I'll throw my own prices out: I have $2k to spend on a new 1080p projector. I would spend $1k-$1.5k now on a current Panny or Samsung or Optoma (I'm not really in the market, so I'm not sure what I'd buy) but I'm saving my pennies until I can get a 3D 1080p PJ for $2k, and not make (much of) a sacrifice on 2D PQ. If I could name my price and my tech: that would be the price and the tech would be Infitec or something very similar. I don't want to mess with a silver screen if I don't have to, and I don't want to deal with 2 PJs (if I don't have to) and I don't want heavy, expensive, battery powered active glasses. And I want something that will work with existing media (PC games/media, console games, 3DBD).

So, tell me more about your product/pricing and I will tell you more about how interested I am.

akhaksho: yes, it is a color wavelength system (and wavelengths can be chosen so that existing glasses are compatible), but it uses different kind of filters on projector side, put at different places within optical path. The filters are produced according to our specifications by a specialized optics company in United Kingdom and are of very high quality.

xhonzi: you have described my ideal system as well, unfortunately we are not there yet with pricing and features... We are still finalizing all the details - will need at least few weeks more to determine everything - but we will probably have to start in $10-20k range. 2 PJs are still required.
We also hope to contact some of the big projector manufacturers and share the technology, which should bring the prices lower further.

About color calibration... to our experience, it requires quite a complex model to do it properly. After many months of experimenting, we've come to a model with 125-vertex cube, each vertex with 20 parameters; 4-dimensional matrices, interpolations, constraints... lots of mathematics and locking engineers in a dark room to stare at calibration patterns...

Interesting. Do you have any info online where I could learn more? Are you a startup?

Thanks for the additional info. Is that $10-$20k per PJ, or for a pair?

Why can't we take an existing 120hz (4x colour wheel?) DLP projector, put the filters on the colour wheel, add the colour calibrators, put on some glasses, and call it done for an affordable price?

Okay, I know we're not there yet... but come on!

Personally I'm only interested in polarized 3D. Glasses are the cheapest around and I can use my Gunnar 3D and Oakley 3D eyewear with it. Not to mention it supports all HDMI 1.4 components with the Optoma 3D-XL. Way cheaper too.

Polarized is nice... if it weren't for that darn silver screen and the darn hotspotting that it comes with. It's also inherently a dual PJ system, or an expensive polarizer add on. But other than that, I'd be happy with it.

P.S. You're of course welcome to your own opinion, but why did you come into an Infitec thread just to say that you prefer polarized? Maybe you're just trying to give Pterodactyl another data point.

P.P.S. Have you seen Dolby 3D/Infitec? It's the best commercial 3D I've seen, and I was pretty happy with polarized before. I still am happy with commercial polarized 3D, but Dolby/Infitec is superior. And I think due to the unique challenges for polarized on short throw projectors- I think Dolby/Infitec would be a better solution in the home... if they could just get the price down on the R&D. I think the actual physical cost isn't too high, it's mostly just the R&D. (someone correct me if you know better).

The web is still being worked on and 3D-related contents is scheduled to go online next week or later. We are not a startup, we have many years of experience in R&D of industrial electronics and are a partner company of some of major FPGA chip manufacturers. The 3D technology for projectors (patent pending) is actually only one of several we have developed.

The mentioned price estimates are for a complete system: 2 PJs, software, glasses (undetermined number, we were thinking about 5 pairs for home and 10-20 for business users).
We are awaiting samples of ~$20 glasses, but will offer more fancy models too. We can add preconfigured PC and projector mounts and screens, if there is demand.

xhonzi, I 100% share your opinion, very high price of existing systems was one of the things that motivated us to try something new and improved. Costs of materials and work, however, simply set some practical boundaries for us too.

Thanks for the assurance! Well, let me know when you get near my neck of the price woods... I'll let you know if I win the lottery.

My new filters:
http://img811.imageshack.us/i/newfilters.jpg/
380 euros

Jack-Bauer

Are these the new filters that Infitec was said to be showing
at the ISE show? Matching glasses available, too (and at what
cost)?

Also, do you have any insights about the amount of light these
filters are losing?

Thanks for any information you might have.

Sticks

So - for a great infitec system, one would need:

-Two nice 1080p projectors with the following requirements:
-status: Plenty of them
---Lens shift (so probably LCD)
---Bright (If I read the above correctly, total light transmission is about 2/3 of the rating of *one* light path - so if your screen size/ambient light would need a 1000 lumen pj, you'd need a pair of pj's, each with minimum 1500 lumen)
---no short throw (1.7:1 or higher)
---anything else?

-glasses - now available continuously on ebay for $30 (there are several auctions going on right now at that buy-it-now price)
-status: Plenty of them

-demultiplexing- with the radiancemini 3d and the slew of forthcoming boxes like the 3dxl, cypress demultiplexer, 3d-vip 3d-theater and others, taking an hdmi 1.4 3d signal and converting it to a split signal is now pretty much no problem. Costs vary from $650 (3d-xl boxes are showing up for $319 preorders) up past $2500 ($1400 or so each for radiancemini 3d's).
-status: one available for $2800, lots of other options in preorder or pre-release status

-Color correction
-Status - hopeful?



So basically, one could get a pair of $1500-range lcd projectors ($3000), two optoma 3d-xls ($650), glasses ($30), and the setup would work with any hdmi 3d source, and the user would get a wonderful, low-extinction 3d effect... but would be limited to probably-not-quite-sufficient color correction. So what are the options there?

I know that the color management in most entry level projectors (at least the ones I've dealt with) simply isn't up to the task - the adjustments are there, but they don't have the range to deal with the major color shifts inherent in infitec filters.

-So there's an old box for a couple $k, and it doesn't support hdmi, much less hdmi 1.4. Not really a reasonable solution IMO.
-dedicated htpc would work for anything sourced from the PC itself, but would not function well for other sources (standalone br3d players, set-top boxes, video game consoles, etc), as the only hdmi 1.4 compliant video input I'm aware of is the aver3d, which is only compatible with nvidia, which in turn is not compatible with dual outputs. Are there other ways to input a hdmi 1.4 source into a pc? Or I suppose a dual htpc could work, placed in the chain just after the demultiplexer. Man that seems inefficient though!
-radiancemini3d has built-in CMS - I asked in the radiancemini thread if that would be sufficient for infitec color correction and never got an answer. Still, two of these could potentially serve as both demux and cms. Anybody got $2800 laying around to test with?
-3d-vip theater product is also reputed to be a splitter and a cms. reputed price is around $500. No release yet, but expected march-april


So it looks like this might be really feasible soon, if a true CMS is enough to handle the color correction. Anyone with CMS experience have opinion on whether it would have the range for this kind of correction?

Keep me posted!

My answer to private messages I got about the filters (lets share this info with the other members):

I got my new filters from a Dolby reseller in France. They are listed as "Cat. No. 835 Dolby 3D Calibration Lenses (left and right) $320 " in http://www.dolby.com/professional/pr...rice-list.html (see at the end).

These are bare 5cmx5cm square flat filters, about 2mm.thick. I built the frames.

Result: A little better than when using filters from the glasses (allows for a wider beam). Still, as I am using very short throw projectors (1.5 : 1), I am getting slight color shifts in the corners (beam angle is not 90 degrees on the edges of filters, so interference layer thickness varies). Resulting ghosting is still very reasonable (much better than a polarized setup in any case). I am getting a value of less than 2 with my favorite ghosting test: http://img337.imageshack.us/i/ghostingtesthalfsbs.jpg/

My hidden goal was to get flat filters in order to integrate them right inside the projectors, beetween the lamp and the SXRD devices (light beam is hopefully parallel at this location). At the moment I am a little lazy to do that, but I will keep you updated should this change...

How about Color Correction? Have you made any progress there? If I decide to go this route I wouldn't mind recoding my movies with avSynth/x264. I have to rip apart the blu-rays and re-encoded the right stream anyway.

My Stereo Passive setup will be powered by HTPC only, so I have a lot of options. I am torn between polars and Infitec. Does anyone have any idea how polarized light would be affected by anamorphic lenses? I was thinking if I go Polar that I'll have to put the polars between the anamorphic lenses and the screen, big polars.

Color correction is now perfect for me. I cannot tell any differences in colors for both eyes any more.

But.... this is done through AVIsynth scripting. So Its OK for encoded movies, not for gaming (so far...).

For Blurays or Bluray ISOs I just dont know as I am not using any (for reencoding 3D blurays, google SSIFsucka).

Any Player which can use DirectShow filters (specifically ffdshow) can use my color correction algorythm. I dont know about PowerDVD.

Movie has to be played side-by-side or top-bottom, not frame sequencing or whatever else.

I know these constraints are a drawback but if you comply, you'll never come again to silver screen, believe me.

For about 40-50$ (2 pairs of Dolby3D glasses - they are listed at 17$ each), its worth a try... without anamorphic lenses for the moment.

If you are convinced, I suggest you go the route I am going in trying to implement reals flat filters (the ones at 320$) right inside the projectors, beetwen the lamp and the LCD/SXRD/LCOS whatever (there wont be anything special between the generated image and the screen). This you cannot do with polars.

Of course, there should be a way to set the filters ON or OFF. I am thinking about this kind of servo mechanism you use in models. I have some. Keep posted.

terrific can you link me to your latest code/scripts?


fine with me, don't care about games


I am converting blu-rays right now, I already know how to do that, It would be very easy for me to add the avsynth color correction



How is the performance of the filters in real time? For high bitrate HD content?



I am using a dual file format, all good there


sounds good


I don't think the anamorphic lenses are a problem. I am pretty sure I can set it up like this: pj > infitec > he lens > screen

I was concerned about anamorphics after a polarizer, potentially messing up the polarized light.


so there are more available?


I would say it would be easy to do that and build a caddy type thing for the filter so you could go back an forth between polar and Infitec.

Exciting times, gentlemen! Keep up the good work.

In case it helps anybody, the first thumbnail for this post:

http://www.avsforum.com/avs-vb/showt...6#post19426946

has the spectrums that each lens in the Dolby glasses lets through. I was thinking that the Sony VW200 might work well for a dual projector system with this system given the Xenon bulb, but it looks like even its spectrum is far from ideal.

--Darin

Busy today. Will sart providing you with the material tomorrow.

EDIT: http://membres.multimania.fr/chrono2...correction.zip (right click and save)
Thats for a start. Explanation/Usage/EditingColors later.

Wow that color correction is extreme!
Not fast enough for real-time on my i7 using separate 1080P left and right files

I am not sure how to make my script do full SBS
I guess it doesn't really matter that I don't know how to make Full SBS because I will be re-encoding these streams individually with x264 prior to viewing anyway.

I am just curious.

I attached a screen shot of the script in action, like I said before the color shift is pretty extreme, also the two frames are a little out of sync because I was skipping around a bunch to see how it looked.
I am really excited about Infitec, I have been buying and converting 3D Blu-rays while researching passive projection viewing methods. I think I am pretty much sold on the Infitec method, no silver screen required. So far I have Avatar, Resident Evil Afterlife and Paranha. Saw Final Chapter is on the way. I built a program with WPF that rips 3D Blu-ray with eac3to then constructs the right eye stream from the left and the delta and encodes it at the left eye bitrate with x264. I'll be releasing it once it is a little more polished. I attached a screen shot of that also. I plan to integrate the Dobly correction as one of the output options

Yes it is. If you think of it the other way around, your jpeg picture shows you exactly how it would look through the filters with NO color correction!



I am using an AMD 1090T / 6 cores / one thread per core @ 3.2GHz along with a 4Gb DDR3 RAM.
What I can do in real time without a glitch:
- 3D half SBS with color correction (one file 1920x1080)
- 3D full SBS with color correction (one file 3840x1080)
- 2D 720p with frame doubling (as per http://forums.guru3d.com/showthread.php?t=288017)
- 2D 1080p with frame doubling
Not powerfull enough to do color correction AND frame doubling, even in halfSBS.

I am sure your i7 can handle this as well.
A trick I use : Force Zoom Player to use affinity with the first 5 cores (imagecfg.exe) so that ffdshow/AVIsynth can fully use the sixth core. Not sure this will work with Intel's but for my CPU its definitely an improvement.


Wow, your are an expert. I do not pretend to be the same. My skills are limited to basic-like programming. I make extensive use of WinBatch and a little C++ but thats all.


Remember that color correction profiles strongly depend upon the kind of projectors you use, and specially the lamps.
If you use the same typical UHP 200w lamp that is very common now, my tables should be ok for a start. This is not the case if you use a Xenon lamp for example (which is better than UHP but you will have to recalibrate).
Ideally, specific calibration should be done for each kind of projector. I intend to recalibrate once a year.


CALIBRATION. Creating the Dolby125.txt profile.

I have built a set of Winbatch (iterpreter) routines to show/edit calibration patterns on the screen.
Unfortunately, these are not "polished", but still usable by anybody. The best would be to have winbatch installed on your system, so you can edit the routines at your wish. Otherwise, I can compile the routines to EXEs for you.

I am writing a help file on how to use the routines and make the calibration. That may take a couple of days.

Basically, you have to set your graphic output to 2x1080p (3840x1080) and let the graphic card driver split the screen in half (affinity or horizontal span if ATI, whatever? if NVIDIA). All my patterns are 3840x1080.


Very interesting. That proves you have to calibrate for each projector. Infitec claims that they can do color correction for almost any kind of projector, including the UHP type, which is the worst case, as show at the end of http://www.jumbovision.com.au/files/...hite_Paper.pdf (terrible, isn't it?). UHP lamp is cruelly lacking red....

By the way, remember that Infitec and Dolby DO NOT use the same wavelengths. So stick with only one supplier. My sample profiles/tables are for Dolby filters/glasses.

Still I completly disagree on:

This is true only if you keep the primaries as such and only adjust their levels. But this is not the case when correcting. You have to matrix the colors (thats the reason why you cannot do that with the card driver or the projector settings).
For example, for the left filter, pure red [255,0,0] is converted to [255,68,0]. It means you add some green, still keeping red red. And because green is not blocked at all by the left filter, yo add a huge amount of brightness.

All along the calibrating process, you will be facing a tradeoff between color accuracy and overall brightness. I found that a 40% transmission factor (60% light loss) gives an enough accurate color spectrum, even in reds.

Jack

That is interesting, I never thought of it that way


Well I have an i7 laptop, Sony Z12, it is a dual core mobile i7, not quite the same as your AMD rig.

I plan on building a dedicated HTPC for this so maybe I can build one strong enough for real time calibration



WPF/C# is easy, all it is a program that sends out command line arguments and parses the results. You could certainly write C# if you can write C++


My laptop also doesn't have dual outputs, I can split it across my laptop screen and a TV or projector. I am in the planning stages here, trying to figure out what works best


Crap, I though the calibration could be done to match the filters not the filters / projector. This makes it a bit more complicated. Also it means I will have to get a better understanding of your excel file so that I can generate my own RGB tables.


You seem to have a very good understanding of the color matrix and generating the RGB tables, I am a bit lost there. I am hoping you can explain it more so that I will be able to tune some tables for my setup. No rush... as I currently don't have a setup.

All my files. Compiled and sources.
http://jptheking.free.fr/3d/Dolby3D_calib-v1.zip

Please read _readme.doc

Jack

Very helpful thank you.