Does IMAX 3D picture differ in any way from a non-IMAX 3D picture?

[Kevin]

I was just wondering, for all yoou people out there that know loads of cool stuff, at the cinema, does an IMAX 3D picture differ from a regular cinema 3D picture?

The reason I ask is that I went to see Avatar in 3D when it first came out at my Odeon multiplex. A big screen, but just a regular 12 screen cinema.

I watched it, loved it and had absolutely no adverse effects from wearing the 3D glasses for almost 3 hours.

Today, I decided that I would like to enjoy the Avatar IMAX 3D experience, so settled in my seat to watch the movie, and within 20 minutes I felt nauseus, and headachey, and basically had to take my glasses off for the rest of the movie.

It took about an hour to get back to feeling relatively normal, by sitting there with my eyes shut, and just listening to it, but even after I felt better, I didn't dare put my glasses back on.

Anyway, could it be bacause it was an IMAX showing that I felt so ill, but was OK for the non-IMAX showing? Could it have been a dodgy pair of glasses? Bad seat? I just don't want this experience to put me off 3D movies in the future.

Thanks,
Kevin.

[Prav]

Haven't got an answer but I noticed that the 3D effect was less pronounced on IMAX - but again may be due to the glasses. Interested to hear others' opinion.

[anephric]

I think the polarising glasses are the same, pretty much. I'm not sure why the 3D effect would be any different.

[KennyVader]

I think it's a slower frame rate for Imax 3D. What kind of Imax was it - proper traditional large frame film-based Imax (e.g. BFI Waterloo) or Odeon style "Imax Digital" otherwise known as "Imax Lite"?

The normal digital 3D (non-Imax, e.g. Real D or Dolby Digital 3D etc) runs under something called Triple Flash which means the digital projector has been upgraded to show each frame of 3D films three times - so it shows L - R - L - R - L - R of each frame in 1/24 of a second, so you can sort of argue that it's 72fps (but every three alternate eye frames are the same). I do not know the exact details of proper Imax 3D but my understanding is that it's still at the same 48fps that normal 2D Imax is at (and has two apertures both showing continuously/overlapped rather than alternating).

[Kevin]

Originally Posted by KennyVader

I think it's a slower frame rate for Imax 3D. What kind of Imax was it - proper traditional large frame film-based Imax (e.g. BFI Waterloo) or Odeon style "Imax Digital" otherwise known as "Imax Lite"?

The normal digital 3D (non-Imax, e.g. Real D or Dolby Digital 3D etc) runs under something called Triple Flash which means the digital projector has been upgraded to show each frame of 3D films three times - so it shows L - R - L - R - L - R of each frame in 1/24 of a second, so you can sort of argue that it's 72fps (but every three alternate eye frames are the same). I do not know the exact details of proper Imax 3D but my understanding is that it's still at the same 48fps that normal 2D Imax is at (and has two apertures both showing continuously/overlapped rather than alternating).

Ah, that's very interesting, and does explain why I felt OK at the Odeon (regular), but sick as a dog at the IMAX at the Glasgow Science centre.

I guess this is the kind of effect that you would get if you tried to play 3D TV through a non 3D TV. The frame rates & sync would be well down, and you could easily end up with a splitting headache from temple to temple (not a lot of fun !)

Thanks for the info. I think I will steer clear of IMAX 3D in future.