Where to sit in a 3D cinema and how do they do it?

[Freke1]

I go to this 3D cinema (seen Pandavision, Dinosaurs and Haunted mine):

and tried to sit different places.
The screen is ~15m and I prefer (so far) to sit close ~10m.
This gives immersion since main vision (except edges) is seeing the 3D world and looks most natural.
So where is the best spot?

Also this is nothing like my tiny monitor, there's no ghosting, little light loss and I can't see the pixels so it looks like high resolution. The screen is white, not silver color. So how do they do it? The movies are probably 640*480 aren't they? They ones I've bought looks terrible fullscreen on a 19" monitor so how come this looks so good on a 15m screen? What is the secret? (they use standard polarized glasses).

[cybereality]

I am not familiar with those theaters but certainly the resolution must be better than 640 x 480. Thats not even DVD quality.

[Likay]

If the glasses are polarized it's most probably a silverscreen or maybe a virtual black screen which is rearprojected (projectors are at the other side of the screen). Virtual black screens are black when looking at them when projectors are off.
Even if it's called "silverscreen" it's experienced close to white. There can be a "glare" since the screen works a little like a mirror. I notice this only when taking pictures of it though. When trying the pandavision at Maxxima-Liseberg i found like you that the "best" spot was about 10-12 metres from the screen. Moving closer to the screen decreases the experienced deptheffect (don't ask me how come... ) while i had about the same depthexperience from 10-15 metres and backwards. But since fov decreases at longer distances i definitely prefer being at 10-12 metres in that cinema. I notice the same phenomena at home. Ideal distance to a 100" screen seems to be about 3-4 metres.

[Freke1]

ok, seems similar to my experience regarding distance/FOV.
The cinema don't use rear-projection because if You stand up the light is blocked.

This cinema is a couple of years old so I would expect:
no HD - but DVD (720*576) resolution which means 2cm pixelsize.
lots of ghosting - the screen is white (like a white wall in a house) so no silverscreen hence depolarization.
However the experience is much better in reality.

What I'm thinking is that if they can do it nearly perfectly on a 15m screen, then I can do it at home on a cheap 5m screen (non-silver) and with 2 cheap non-HD projectors (~800*600).

[Likay]

Ok. Maybe it's an infitec similar technology? Still passive glasses without need for a special screen but not polarized light. Instead they're using colorfiltering, like anaglyph but two red nuances, one nuance for each eye and the same with green and blue. Just a theory if the screen really is white. In theory the screen doesn't have to be silverish or grey to be a nondepolarizing screen. The whiter it is the better for as long as it keeps polarization.

With two projectors and infitec filters you should be able to build a passive rig using those. There will be no need for a silverscreen but you'll need at least two pairs of infitec glasses. Look this thread on the iz3d forums. http://forum.iz3d.com/viewtopic.php?t=1306" onclick="window.open(this.href);return false;
It did work for the guy but he had problems with coloradjustments. I'm not sure if it can't be adjusted but it doesn't seem simple.

[Freke1]

Thanks, great link!