[DIY] Dual LCD Polarized display for Cheap!

[nubie]

Cool, I updated the forums.nvidia thread, but I didn't here.

I built a new rig to hold the screen and the mirror with Wood, angle brackets, threaded rod, and some angle stock.

http://picasaweb.google.com/nubie07/Ste ... 7970053378

This is a whole gallery of the new stand. The top monitor is having backlight issues, one of the fluorescent tubes may have died.

[The_Doctor]

How does the ghosting of the planar setup compare to the iz3d monitor? More, less? What about with crt and shutterglasses?

[nubie]

I notice nearly no ghosting (I have seen it, but usually it is on the edge of a building in shadow with a bright sky beside it, and I am not sure if that is due to my warped acrylic mirror or the glasses being askew on my head.)

I haven't yet tried a glass mirror, but I can clearly see the warp in my acrylic as a ghost pattern through my polarizer.

I haven't tried an iZ3D, so I can't really say.

As for CRT, there is absolutely no comparison, this is near perfect, and it can't switch eyes on you or lose synch as a bonus.

I would say 2 to 10 times as much contrast easily, and no flickering (I can't stand any flicker, even a standard monitor at 60hz will give me rioting headaches.)
It is a trifle dependent on your iris level, so if you were gaming in an entirely dark room you would see more ghosting, but I just have a 60-watt bulb on and it is nearly 100% because my iris is compensating for the ambient light. Fun fact, your eye is sensitive enough to catch a single photon of light, this makes it pretty tough to fool


If you wanted to set up a front-surface mirror and a pair of any type of monitor for direct view, see here http://www.crystalcanyons.net/pages/Tec ... ewing.shtm

This method has you look at one monitor directly, and use a standard mirror (or a front surface mirror) on your other eye to look at the second screen. I have thought of using this to make a franken-HMD, possibly mounted on an eye-level shelf with a movable chair, or a floating helmet supported by some sort of arm or chain to the ceiling. There are 10"-14" LCD screens that are 1280x768 or 1900x1200, and you could make quite the helmet rig with couple of those.

[winch8]

I've just bought a pair of paper glasses linearly (45/135) polarized. I discovered that my acer 1916w lcd monotor (19" widescreen) is polarized at 45° because
when i wear those glasses my right eye sees the scrren almost black while the left eye sees the scrren almost normaly bright. But i noticed also that i need some
light behind myself that hits the monitor becasue otherwise the right lens can't block too much of the screen light and this would surely cause severe ghosting on
a planar setup. Plus if you tilt your head even by very little margin the blocking filter begins to let more screen image to pass trough (ghosting would be assured), and if you
tilt your head a little more the screen image becomes too much visible to the right eye and you would simply loose the 3d effect and see a double image.
Real D 3d movies at the cinema like beowulf use circular polarization and also imax 3d theaters use circular polarization...i think itì's the only really effective and
comfortable way to see 3d, apart from shutter glasses with high refresh rates screens (but they don't work fine anyway on lcd monitors).

[nubie]

You are correct of course, and if you wanted to purchase circular polarizing material and put it over the screens you could, and then you wouldn't have that problem. This is a big step up from direct-mirrored, you can move around and all you need to do is keep your head level, which I usually do when I am on the PC.

I would almost rather buy an iZ3D or Zalman than get circular polarization, but I would want to test drive them first to see exactly what it was like (especially using a non-native pixel perfect resolution on that Zalman to see if the effect still works, some games have zero support for custom resolutions or non 4:3 displays).

I would really like a dual DLP projection rig with circular polarizers, then there wouldn't be any problem with tilting of the head.

[winch8]

Mmmmmm...putting circular polarized glasses over the screens...i read that circular polarized light CANNOT be reflected by mirrors so the half mirror could not reflect the
image of the second monitor. Do you know if it is true?

[winch8]

I am thinking that the new polarized glasses promised by iz3d could solve this problem!
In fact if, put the case, they are a sort of multiple linear polarized glasses, meaning that one filter
blocks all light polarized between 0°-90° and lets pass all light polarized between 90°-180 and the other filter
viceversa, the polarized light of lcd monitors would be filtered much better just like circular polarization!
Standard linear polarization is useful for applications like photograpy but the one i hypothesize is much
better for stereo 3d...
Do you think it is possible?

[nubie]

I don't know, I would rather have a mitsubishi 3D DLP for around $1600 at 60 inches!! http://www.amazon.com/Mitsubishi-WD-607 ... B00166BNFS

[distantreader]

I had couple of Dell 2407WFPp but for the life of me searching on the net for their polarization characteristics still couldn't find out, none of the specs I've seen mention this characteristic, just hoping someone in this forum might know what it is? (I'm hoping they are 45 degree to make my life easier), contemplating of putting them into a planar setup and in the "researching" phase in hope of a better S3D experience than CRT/shutterglasses. Any help is appreciated.

EDIT: using my shutterglasses with normal position I can see the screen of the LCD, tilt the glasses 45 degree and it's almost black. With the shutterglasses at 90 degree it's clear again. So even this doesn't tell the polarization angle of the Dell's (since I don't know the polarization angle of the shutterglasses, I assume the pol. angle of the shutterglasses are the same as that of the polarized glasses that people used in their planar setup ?), is it safe to say the Dell's are polarized at 45 degree ?

EDIT2: Tried the shutter glasses with my laptop LCD and found that with normal horizontal position it's black and in perpendicular position it becomes clear so I think the best way is to buy a pair of polarized glasses and test it with the Dell's LCD to make sure it works/or not and if the 45 degree glasses don't work with the Dells then I should be able to try the 90 degree ones, I hope they do exist.

[StereoGaming4Me]

I'm about 98% complete with my dual acer 20" planar cube.. was wondering about convergence settings in the old nvidia cp but the other thread helped out there. The last thing I'm trying to figure out to make the planar complete is whether or not my top lcd needs the brightness and contrast to have higher luminance than the back lcd. On the XP desktop I still get a horiztonally flipped image from the top lcd until I engage a game - then the top lcd flips horizontally after DX9 is implemented.

Should the back lcd or top lcd be brighter and higher in contrast for tweaking convergence and separation, since that is the final step here and I haven't had a lot of time to do any testing?

Thank you to anyone who can offer advice! Have a great day!

[StereoGaming4Me]

Hey nubie.. how are you?

I was wondering about the pop out effect with this.. mine is set up correctly and plays a good number of games but if there is any pop out it somewhat just shows at the front of the cube at a seemingly closer distance to your eyes. If a bracket method is used, does any kind of light become a big problem anywhere along the line with reflections and shadows anywhere? I'm asking because in the dark and with a bracket where you can't notice the glass too much that perhaps the S3D effect does appear to pop out from the screen into thin air as well as depth... because mine is like looking into an lcd monitor almost 2 feet deep with a very compatible game. I would think with a bracket you would have a neat holographic pop out effect in pitch dark, but another post mentioned something about needing a little light so the pupils do not dilate to reduce crosstalk.

It would be great to hear a comparison for the bracket method and any change in pop out or S3D for your setup!

Peace

[nubie]

Sorry, I haven't had mine setup in several months, busy with broken down cars and major home remodel (and a backhoe and Diesel truck for a friend).

Half the fun for me is playing around with all of the different settings, I don't really like pop-out personally, so I try to avoid it. I like it if it looks like a window into another world. My eyes nearly refuse to Diverge though, so maybe that explains my reticence.

Now that you mention it I want to try a "pop-out" demo in a dark room, maybe something like a spinning globe or rose.

What did you use for a mirror? I am thinking of buying a real glass beam-splitter (AKA half-silvered, two way mirrored, teleprompter mirror) from a local glass store, my acrylic is warped and the coating is water damaged (did I leave this in the rain or sneeze on it?)

I am glad you got it working , I need to build a proper mirror bracket for mine that can be adjusted with a simple screw, I have an idea that may only take a couple dollars, just need to get my car running and these rooms built.

[StereoGaming4Me]

Sorry, I haven't had mine setup in several months, busy with broken down cars and major home remodel (and a backhoe and Diesel truck for a friend).

Half the fun for me is playing around with all of the different settings, I don't really like pop-out personally, so I try to avoid it. I like it if it looks like a window into another world. My eyes nearly refuse to Diverge though, so maybe that explains my reticence.

Now that you mention it I want to try a "pop-out" demo in a dark room, maybe something like a spinning globe or rose.

What did you use for a mirror? I am thinking of buying a real glass beam-splitter (AKA half-silvered, two way mirrored, teleprompter mirror) from a local glass store, my acrylic is warped and the coating is water damaged (did I leave this in the rain or sneeze on it?)

I am glad you got it working , I need to build a proper mirror bracket for mine that can be adjusted with a simple screw, I have an idea that may only take a couple dollars, just need to get my car running and these rooms built.

I got a 70/30 teleprompter mirror from telepromptermirrors.com or something close to that for $152 or so. What showed up appeared to be a 50/50 piece instead after the "white card test" proved nothing, and they accept no returns at all, but the 50/50 works just fine. I'm very happy with the planar. If you order from them, as soon as the glass arrives call them and ask them to walk you through the white card test to see if they sent you a 50/50 instead of a 70/30 or 60/30. If you see no gap when a white index card is at the mirror, then that is the silvered side according to that company. On mine, there was no difference and both sides had the gap, but the reflected top lcd colors are slightly off in desktop mode.. would you say that is that normal? Also, I have to tilt the berezin $3 glasses slightly clockwise on my face to eliminate ghosting sometimes.

Thanks!

[distantreader]

Hi folks, there are lots of posts about this dual LCD + polarized glasses but all are about a vertical setup. I got a noob question that's been gnawing: why there is no talk about setting it up horizontally, similar to planar/mirror setup? Is it because it's technically not possible? This would eliminate the hassle building a framework for the vertical monitor. (You guys can see I haven't dwelled into this too much technically hence this silly question, BTW anyone has pointer to some good read on this dual LCD+polarized stuff better than what google gives?). Thks. DR

[Likay]

There's nothing that goes against a horisontal setup. Either you can have both monitors close to each other and view them crosseyed. (Crosseyed for long times = Eyestrain)
Another way is to have one mirror and mirror one monitor horisontally and have one eye looking straight at one monitor and the other looking at the other one through the mirror. Advantages with this is that you wont need any semireflective mirror. One simple mirror will do. The drawback with this kind of horisontal setup (and a quite big one) is that you need to have your head perfectly aligned to have a proper effect though.

It should work though!

[distantreader]

Yep I tried the "2 LCD + Mirror" method using just a handheld small mirror and saw that it works with a head movement restriction and that's why I'm interested in "the beamsplitter + 2 LCD + polarized glasses" technique since it solves the head movement restriction problem. But so far I've read only about vertical setup of this technique and none uses the horizontal method given that with the horizontal setup there is no need for an elaborate framework to hold the upper LCD, in addition both LCD's can still be used normally easily (just remove the beamsplitter and you can have a dual monitor setup for work, put it back in and you have nice S3D setup for games), I guess that's why I thought there might be technical issue that prevents such a setup and want to check first since to me it seems more practical and useful than the vertical method. DR

There's nothing that goes against a horisontal setup. Either you can have both monitors close to each other and view them crosseyed. (Crosseyed for long times = Eyestrain)
Another way is to have one mirror and mirror one monitor horisontally and have one eye looking straight at one monitor and the other looking at the other one through the mirror. Advantages with this is that you wont need any semireflective mirror. One simple mirror will do. The drawback with this kind of horisontal setup (and a quite big one) is that you need to have your head perfectly aligned to have a proper effect though.

It should work though!

[Likay]

And of course you should be able to use horisontal with a semireflective mirror as well. If the polarization of the lcd's is 45° or 135° it should work without extra retarders+polarizers.

[distantreader]

I'd hope polarized glasses vendors should have all kinds of flavors to sell and not just 45/135. I don't know what my LCD's polarization are except that they are different from my laptop's which also an unknown. It's likely that's the laptop being 45 degree and the desktop 0 degree, in that case I need to order a pair of 0/90 polarized glasses without resorting to retarders, I think.

And of course you should be able to use horisontal with a semireflective mirror as well. If the polarization of the lcd's is 45° or 135° it should work without extra retarders+polarizers.

[Likay]

The problem is that the semireflective mirror only handles the polarizationshift if the lcd's polarization is 45 or 135°. (Otherwise you need to shift polarization of one monitor 90° or both 45°).
But as said: It's nothing that some polarization foil (slight expensive) in combo with retarder (very cheap) cannot fix though.
Check polarization.com for both retarder as well as for polarizers.
Use qw-retarder for 45° shift and hw-retarder or double qw's for 90° shift.
This is only needed if your monitors have 0 or 90° polarization angle.

[distantreader]

The problem is that the semireflective mirror only handles the polarizationshift if the lcd's polarization is 45 or 135°. (Otherwise you need to shift polarization of one monitor 90° or both 45°).

This is good to know. I wasn't aware of this. Tks.

But as said: It's nothing that some polarization foil (slight expensive) in combo with retarder (very cheap) cannot fix though.
Check polarization.com for both retarder as well as for polarizers.
Use qw-retarder for 45° shift and hw-retarder or double qw's for 90° shift.
This is only needed if your monitors have 0 or 90° polarization angle.

Doesn't this cause additional loss of brightness? I hope it doesn't become as bad as what LCD shutterglasses has. Let's see, loss due to beamsplitter, loss due to additional retarder, loss due to polarized glasses. It can't be good. Before I spend time and money on this, I'd like to know more about this. Thanks Likay.

[Likay]

Yes, you'll loose a slight bit of light. However this can be used to compensate eventual light differences because of the semireflective mirror. Simply use ev. retarders/polarizers on the experienced brighter screen.

I once made a small vid how a retarder work. It's a quarterwave retarder and i use to it to shift 90° (should be two qw's or one single halfwave retarder for better performance) . You can check and estimate the light loss there.
http://www.mtbs3d.com/phpBB/viewtopic.p ... 8&start=14" onclick="window.open(this.href);return false;

[nubie]

Hi folks, there are lots of posts about this dual LCD + polarized glasses but all are about a vertical setup. I got a noob question that's been gnawing: why there is no talk about setting it up horizontally, similar to planar/mirror setup? Is it because it's technically not possible? This would eliminate the hassle building a framework for the vertical monitor. (You guys can see I haven't dwelled into this too much technically hence this silly question, BTW anyone has pointer to some good read on this dual LCD+polarized stuff better than what google gives?). Thks. DR

Good Question, since I haven't posted the pics in this thread yet, here is a link: http://picasaweb.google.com/nubie07/3DMonitor#" onclick="window.open(this.href);return false;

It works, but then where do your keyboard and mouse go? (Just kidding, I have used a slide-out keyboard tray before.)

This is how I used my setup until I got the mount built.

[distantreader]

Great! I've bookmarked it for future reference.
Could you pls compare the two setups with regard to ease of use, quality of 3D?
Thks much,
DR

Good Question, since I haven't posted the pics in this thread yet, here is a link: http://picasaweb.google.com/nubie07/3DMonitor#" onclick="window.open(this.href);return false;

It works, but then where do your keyboard and mouse go? (Just kidding, I have used a slide-out keyboard tray before.)

This is how I used my setup until I got the mount built.

[nubie]

Ease of use?

Mounted: Expensive, skill needed to construct, more room for keyboard and mouse, better view angle if you like to look down at the screen. May bump head on top screen leaning forward though.

On a desk: OK as long as you can get the mirror lined up. Best with a platform 8-12 inches above desk height so you have room on the desktop, and so you are looking into the screen. Needs nothing but 2 LCDs and a piece of glass, so near free. Nothing to build, just set on a desk. Option to slide second screen back and use 2 monitors (great if you do any 3D modeling/texturing, or work with Gimp/Photoshop)

I dunno, I think I wanted to build the mounted version because it makes the most sense, you look in a horizontal fashion and getting the second monitor out of the way helps.

[anotherFrench]

hi all, I'm trying to apply this method in a lcd projection system, so I searched a mirror that could do the trick.
I found 1 called "antelio" at a local shop so I guess you can find it anywhere, it seem to work great for desktop use, I tryed it with 2 17" crt's and the results look very good to me:
http://forum.allinbox.com/aspectgeek/Pr ... 9151_2.htm" onclick="window.open(this.href);return false;
I didn't try it with polarised filters, don't want to buy them because the 2 crt's setup was just a test and is too "big" to keep on my desk so I think it's better to use 2 lcd's wich are polarized already but the rendering of the 2 pictures seem to be very good
sorry it's a french forum but you can see the pics anyway.

[nubie]

Cool, I am glad to hear somebody is enjoying polarized light

This is a translation of that forum into English (haven't yet read it, will now.)
http://translate.google.com/translate?h ... 26hs%3DaK5" onclick="window.open(this.href);return false;


For Projection what you are going to need is called a "first surface" or "front surface" mirror and LCD projectors that are polarized at 45° or 135°, also a Silver Screen (or similar screen that claims to Preserve Polarization, or is good for polarized projection ).

I would strongly suggest that the 2 projectors have separate light paths (two lenses at the output). You will have bad results if you attempt to use a splitter (mirror glass).

Instead use First Surface or Front Surface standard mirror (or even a normal mirror for a start.) I have 2 good links to Lumenlab.com forums (you may need to register on the forum.)

[nubie]

This is the most information I have, he says to use aluminum Graffiti paint and add "matte" finish modifier (mix into the paint) paint on a smooth surface for a screen.

http://www.lumenlab.com/forums/index.ph ... reo3d&st=0" onclick="window.open(this.href);return false;


For a design follow something like this: http://www.lumenlab.com/forums/index.ph ... t&p=208802" onclick="window.open(this.href);return false;

[anotherFrench]

I'm sorry, I have to answer point by point because I'm not sure I understand well everything you wrote, my english is very limited, especially with those "technical" words.

Cool, I am glad to hear somebody is enjoying polarized light

This is a translation of that forum into English (haven't yet read it, will now.)
http://translate.google.com/translate?h ... 26hs%3DaK5" onclick="window.open(this.href);return false;

great ! now even I can't read my own text anymore (just kidding)

For Projection what you are going to need is called a "first surface" or "front surface" mirror

I think I understand what you mean but do those mirror exist in half transparent?
for my project I need a mirror that would reflect half of the light and let 50% trough.
even if they exist I'm not sure to find them in france and I think this kind of product may be complicated to ship internationally

and LCD projectors that are polarized at 45° or 135°

you mean LCD monitors right?
I didn't look at the polarisation of my lcd's yet, it was very hard to find 2 15" that would be suitable for DIY project but I read somewhere that if the polarisation is wrongly oriented, I can take the filters off to apply new ones. it won't probably be very simple but to me, this project is meant to learn some technical aspect more than to give the best results.
of course I hope it will work great but the most important is what I can learn from it, as it is my first atempt to create such a project.

I would strongly suggest that the 2 projectors have separate light paths (two lenses at the output). You will have bad results if you attempt to use a splitter (mirror glass).

naah, that would be too easy LOL, I want to try with a splitter first to see if I can come up with some solution, anyway I bought 2 lenses just in case the result is too bad, then I'll use them to create a more conventional setup

This is the most information I have, he says to use aluminum Graffiti paint and add "matte" finish modifier (mix into the paint) paint on a smooth surface for a screen.

it's great information, I did spend a lot of time searching for information, especially about those silver screen because I wish to have a complete DIY set-up so I will read the link carefully and see if it is possible to make one

I thank you for taking so much of your time to answer, I hope this will help me to finish the project in good conditions and soon be able to see 3d on my own selfmade projector

[nubie]

I'm sorry, I have to answer point by point because I'm not sure I understand well everything you wrote, my english is very limited, especially with those "technical" words.

For Projection what you are going to need is called a "first surface" or "front surface" mirror

I think I understand what you mean but do those mirror exist in half transparent?
for my project I need a mirror that would reflect half of the light and let 50% trough.
even if they exist I'm not sure to find them in france and I think this kind of product may be complicated to ship internationally

This is a first surface mirror: http://astroprofspage.com/wp-content/up ... irrors.jpg" onclick="window.open(this.href);return false;

Most "beam splitters" are first surface.

and LCD projectors that are polarized at 45° or 135°

you mean LCD monitors right?
I didn't look at the polarisation of my lcd's yet, it was very hard to find 2 15" that would be suitable for DIY project but I read somewhere that if the polarisation is wrongly oriented, I can take the filters off to apply new ones. it won't probably be very simple but to me, this project is meant to learn some technical aspect more than to give the best results.
of course I hope it will work great but the most important is what I can learn from it, as it is my first atempt to create such a project.

I haven't tried it with the wrong polarized LCD, but the people on these forums tell me to use a "wave retarder", but I would rather just get the correct screens.

To check use properly polarized glasses ( http://www.berezin.com/3d/3dglasses.htm#Polarized" onclick="window.open(this.href);return false; ) :

I would strongly suggest that the 2 projectors have separate light paths (two lenses at the output). You will have bad results if you attempt to use a splitter (mirror glass).

naah, that would be too easy LOL, I want to try with a splitter first to see if I can come up with some solution, anyway I bought 2 lenses just in case the result is too bad, then I'll use them to create a more conventional setup

Well, the light output of a home-made projector will be bad enough, if you try to add a splitter it won't get any better.

Try to go to a glass shop and ask them about a half-silvered or half-mirrored glass, they might have some, then you don't pay money for shipping.

I would build 2 projectors, then project them onto the same surface. One of them should shine on a standard mirror first. (I have done this with projectors that I purchased, it works fine.)