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3D glasses (not the retarded red and blue kind)

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I want to build some 3D glasses (the kind that blocks one eye from the tv after the other at the same frequency and phase that the tv switches between showing the image intended for the left eye and the right eye).

I am new to this site and to building anything useful so your help will be extremely appreciated!

I think that I need 2 LCD's - one for each eye, but this could be the wrong thing to use.

Is it possible to use an lcd (such as those used in a calculator) to achieve my intended purpose? lcd's used in a calculator are clearly too small to cover an eye, so I would obviously use bigger ones (provided they are manufactured). I would also need them to be able to switch on to off at 30 Hz or more. Also, they of course need to be transparent when in the 'off' part of their cycle (which they would be if I understand lcd's correctly).

So are lcd's what I'm looking for or is there a better way to achieve this?
 

Torben

Well-Known Member
Maybe you could look into using the drivers from a couple of cheap auto-darkening welding masks. These things go from transparent to dark in around 1/20,000 (or faster, for the good ones) of a second which should be plenty fast enough for your purposes. They use LCD windows.

A cheap auto dark mask will set you back about 50 bucks new, less used. You probably don't need anything more for a proof-of-concept prototype. You don't need a good mask for this purpose and I think the price would prevent that anyway. :)

Anyway, the important thing here is that yes, LCD can do what you want and is more than fast enough. I remember 3D goggles like this being on the market 10 or so years ago (for computer games, IIRC) so it's certainly possible.


Good luck!

Torben
 

Sceadwian

Banned
Yeah, the hard part is finding the LCD's to use in the first place. Welding mask LCD's would work but you can't trim them they're bulking and welding masks are expensive. LCD shutter glasses are dirt cheap though

How about these? Just modify to your hearts content.
Wired 3D Glasses LCS-LCD Shutter Interlaced VR 3-D NEW! - eBay (item 120341244236 end time May-26-09 18:04:38 PDT)

By the way, be careful with shutter glasses, MANY people suffer from 'VR sickness' while using them, and obviously it's bad for epileptics as well. I personally can't use them longer than about 60 seconds or I get bad nausea. But this is due to the slow flicker rate. Modern 3D movie theaters have rectified the problems of shutter glasses (Do a wikipedia or google search for Real3d) but the technology to do that is not easily within the reach of a hobbyist.
 
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mvs sarma

Well-Known Member
@Dr. McSteinsworth,
You are a doctorate. Perhaps i am not fit to advise . but i fear we need not damage the precious eyes given by god with flickering signals. the television is adjusted for 50frames /sec(25+25 alternate)
and I fear it would not be possible to see flicker free at less than that, even if you use polaroid sheets (even if they could be controlled by an electrical signal, that I HAVE NOT heard of).
 

Sceadwian

Banned
mvs saram, what on earth are you talking about? Shutter glasses have been used for years, and they generally switch at around 60hz. The problem is the DEPTH of their switching. When off one eye is almost completely black, then it turns back on.. This modulation depth is what causes the problems not the frequency. If the modulation depth is deep enough (on off for example) I can see flicker at upwards 1000hz if the duty cycle is 50%, but only when the source is moving, or there's another out of phase modulation nearby (I can see the harmonic flicker) The fact that the switching of the eyes is perfectly anti phase that causes motion sickness when you move your head. I bet if you looked at the optical cortex of a person looking at a 3D screen with LCD shutter glasses on it'd be lit up like a Christmas tree.
 
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tcmtech

Banned
Most Helpful Member
If you have ever been to one of the I-Max theaters when they are running a full 3-D movie, the glasses you get are passive not active. They use vertical polarization for one eye and horizontal polarization for the other.
With the glasses on the movie is as bright and clear as any regular I-max movie but you do have the full 3-D viewing effect! And there is no sweet spot in the viewing area. Anywhere you are at still come across as full 3-D!:)

You will never beat that brightness, color, clarity and resolution with LCD based glasses. Plus the glasses are plastic with plastic lenses. I bet the mass production costs are well under $2 each! :(

Sorry to rain all over you. But to make you feel better go to las Vegas and take in a 3-D I-Max movie! ;)
 

House0Fwax

Member
They use vertical polarization for one eye and horizontal polarization for the other.
The kind that I have encountered (and have dozens of pairs kicking around) have 45 degree polarisation with the apex on the bridge of the nose, so it doesn't matter which way you fold the arms (on the cardboard type).
 

Sceadwian

Banned
Tcmtech, they're not vertically/horizontally polarized or even 45 degrees as house of wax thinks, they're circularly polarized, in opposite directions. And the movie without the glasses is NOT as clean and clear as the non-3D version. I can see the interlaced frames, as a blur to the image without them. It's like watching interlaced video on a computer, only worse because the perspective is different.

Circular polarization - Wikipedia, the free encyclopedia
Real D Cinema - Wikipedia, the free encyclopedia
 
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House0Fwax

Member
Tcmtech, they're not vertically/horizontally polarized or even 45 degrees as house of wax thinks, they're circularly polarized, in opposite directions.
Quote from Wikipedia;
"In stereoscopy, two forms of polarization filters are used: linearly polarized glasses and circularly polarized glasses (see the relevant sections in 3D glasses for further reading.)" (from the article 3-D film)

I'm not disputing circular polarisation, but the kind I have are 45 degree types.
 
Thanks for all the replies.

Why build them? Because I think it would be a fun first project and 3D is cool.

Why are red/blue glasses 'retarded'? Because you look retarded wearing them (unless your a kid). But I guess the same can be said of other 3D glasses. But mainly, the video you are looking at appears red/bluish and not as real as it would look with other 3D glasses and you can still slightly see the red image through the blue lens and the blue image through the red lens.

I will look into the auto darkening welding mask and the wired 3D glasses.
 

Sceadwian

Banned
Sorry house0fwax. I thought Real D was the only polarized 3D viewing system out there, didn't occur to me that someone else might use V/H or various 45 degree versions. Everything release in the state recently uses Real D (that I know of)
 

House0Fwax

Member
Sorry house0fwax.
No problem sir.
The first film I saw in 3-D was 'Fantastic invasion of planet earth' (aka The Bubble 1966). I saw it about 1982 and was surprised that it was not anaglyph (red/green).
I still have the glasses that I had to pay seperately for. However all the films that I have seen since have used the same type.

From what I can gather, circular polarisation was being developed and was more expensive to produce ( which makes sence when you think about either making seperate units or cutting up a big sheet of film).
 

tcmtech

Banned
Most Helpful Member
I could have been wrong too. I just went by what I remember from the gal that explained the I-Max system and how the basics of the 3-D glasses worked.

I remember vertical and horizontal polarization being mentioned and how our eyes are not affected by which one goes to what eye but how that polarization effect can make two polarized and overlapping screen images fool our brain into seeing a false 3-D image.
And having a T-Rex come right out of the screen at me! :eek: :D

As far as the auto dimming welding helmets approach. I worked as a service tech for a welding shop and had lots of hands on experience with the auto dim helmets and honestly most use potted circuit boards and all are tiny surface mount digital controls. So I doubt you will will be able to hack into the control system.

And even when they are in the clear mode they still have a rather strong dimming effects to them. In daylight they are fair to look through but I doubt you could watch TV through one!
 

Sceadwian

Banned
They do it en-masse here in the states. I'm sure they have their manufactoring methods that work well. I get a pair or three (wife and stepson) every time I go to a 3D movie.
 

Torben

Well-Known Member
As far as the auto dimming welding helmets approach. I worked as a service tech for a welding shop and had lots of hands on experience with the auto dim helmets and honestly most use potted circuit boards and all are tiny surface mount digital controls. So I doubt you will will be able to hack into the control system.

And even when they are in the clear mode they still have a rather strong dimming effects to them. In daylight they are fair to look through but I doubt you could watch TV through one!
Hi tcmtech,

I never suggested using the lenses from one for anything more than a proof-of-concept; I just suggested using the drivers. And I don't think it would be hard to interface with one at all, potted or not. All you need is the trigger in signal (grab from the lines to the sensors) and the trigger out (grab from the lines to the LCD). As I also noted, I was mostly just pointing out that LCD would work (despite being likely to make the user honk).

But yes, I agree with your other assessments: passive would be a better and simpler solution.


Torben
 

dknguyen

Well-Known Member
Most Helpful Member
I thought they used polarized 3D glasses now instead of red/green. I just saw an IMAX and it was in colour, looked fuzzy without the glasses. I never bothered to turn my head sideways while watching the movie to actually see if they were polarized.
 

arhi

Member
polarised is nice when you can project the polarised light ... but fairly useless in home env. as your screen cannot change the polarity .... you could try using two projectors with polarised filters but I don't believe even that is that simple as you probably need special canvas to project to as normal canvas will mess up the polarisation... I just tried the laser pointer trough polarised glass, the reflection on the wall is visible however you orientate the polariser filter on your eye hence the "special canvas" problem ...

For "home use", the shutter or color filter glasses are the only solution... I remember the shutter glasses (LCD inside) that were controlled directly from my indigo2 gfx card... those were the times :D .. donno about nosia .. we used to play dog fight on SGI boxes with 3d glasses all the times for hours, no side effects .. (on the other hand, my wife get sick when try to play FPS on normal screen ... so everything is possible) :)

All in all, if you want a "home use" device, the shutter is the only full color 3d display tech .. if you discard color, the color filter glasses will do but that's the one you are familiar with. Note that shutter glasses have to be in sync with the application, you cannot just set some speed on them ..
 

Sceadwian

Banned
arhi, LCD monitors emit polarized light, I'm surprised no one has tried to do 3D with more sophisticated polarized setups.

Some people aren't as seriously effected by VR sickness, I'm not one of them.
 

arhi

Member
arhi, LCD monitors emit polarized light,
yes I know but, you cannot "change" the polarisation ... and in order to have polarised glasses work you need 2 sources (90deg shifted) from same point .. there's no way you can emit from your regular household screen 2 different signals from same point :D ...

As I said, in "home env" you cannot use polarisation ... as for specialised use .. polarisation is a big thing
 
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