Why don't the 3D glasses work?
Sunday, 07 March, 2010
We went to see Avatar the 3D movie.
We bought the 3D glasses home with us but they don't work now. I tried the computer and two different TV sets but they just don't work. Do they demagnetize them when you are leaving the theatre?
Sayed , , Australia
 No, the glasses are still working fine. If you go back to see another 3D movie they will work. (Unless it uses a different 3D projection method.)
Those glasses work because the movie is projected using two separate projectors, with eachprojector using light that polarised in a different way. The glasses allow each eye to only see the correct image for that eye. Your TV and PC can never produce the correct sort of image because they have no way of producing polarised light.
There are ways to produce 3D images for TV and computer screens but these generally use a different sort of viewing glasses such as electronic shutter glasses. These switch the vision on and off alternately between the two eyes, very rapidly and in time to changes in the L&R projected views. Paul Zucker
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PaulPosted: 10/03/2010 re: Why don't the 3D glasses work? Ive always found those 3d movies very hard on my eyes,to the extent of giving me a major headache,and to pc user staff:the link to this site seems to have vanished from the ninemsn homepage-any ideas why ??
(Perhaps they don't love us any more? It will be interesting to see how popular the upcoming 3D TVs sets are. You aren't the only person who is troubled by the effect Paul. -PZ) MaxAPosted: 09/03/2010 re: Why don't the 3D glasses work? There is a comprehensive explanation of all 3D technologies, including that of Avatar, on Wikipedia. JeffPosted: 08/03/2010 re: Why don't the 3D glasses work? I am interested to know if you can effectively watch 3D movies such as Avatar without using these special glasses. I have very poor sight in one eye (could almost be a Collingwood supporter!!)and have found in the past that the old 3D glasses with pictures that had a red/blue (or something similar) technology did nothing for me.
(Hi Jeff. I also have weak vision, especially in one eye. I found 3D Avatar worked for me, but if your vision is really bad in one eye you won't ever get the true 3D effect. But the polarising glasses are still a world apart from the old anaglyphic (red-blue) glasses. -PZ) MikePPosted: 08/03/2010 re: Why don't the 3D glasses work? There are several different ways of making and viewing 3D
A common way is photographing the scene simultaneously from two standpoints about 75mm apart and viewing the two images, one with each eye. There used to be 3D cameras that took two shots at once through a prism. This technique is over a century old yet still works.
Another is to use red/green filters as NASA has done on some of it's 3d panoramae.
Not sure what AVATAR has done, I haven't seen the movie but Paul is probably right in polarisation which is easy to achieve yet hard to pirate via tv
There was an interesting method of producing still photos using laser interferomety, Holography, but the image on glass looked like grey speckle until viewed. The interesting point was if the glass was broken, each piece contained the full image (at a reduced resolution of course) andrew peter collinsPosted: 07/03/2010 re: Why don't the 3D glasses work? It's a shame that cinema's here in OZ don't explain the technology behind 3D projections. It's actually very easy for the novice to understand if given the chance. Over in The States they even offer you a little cloth bag to put your glasses in after the movie thus cutting down waste and cost. You bring the glasses to the 3D movie you wanna watch and you get a discount for re-using your glasses at another movie. Cheers Andy :) |