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Hey there fellow 3d-ers!

I'm going to repeat a couple of unanswered but desperate questions for anybody who has tried or knows about:

1) 3d slide projection using polarized filters
2) taking anaglyphs

I read in the 3d net that a "silver screen" is required, for example one painted silver. Well, I have a bunch of cheap polarized glasses plus one decent filter, and I grabbed a flashlight and the filters and did some testing to see what kind of material retained polarization the best...I found that fine-grain aluminum does a pretty good job, better than silver spray paint, at making a polarized image  projected onto it disappear by rotating the viewing filter (fade, actually). BUT, even at minimum brightness, the image is still slightly visible, AND ONLY FOR THAT PARTICULAR VIEWING POSITION. 

So my three questions are, 

1) does a faded but not disappeared image prevent a stereo effect from being achieved ? (ie. each eye will see mostly its own image but also a bit of the other eye's)

2) why is it that in a small theatre that shows polarized 3d films everyone in the room can see the effect, regardless of position? It seems (from my testing) that one needs to be in a specific position for a particular arrangement of the glasses and projector filters...I looked up close at the screen after the show, and it was indeed silvered, but also with regularly-spaced tiny holes...what is this for?

MY BIG BURNING QUESTION:

3) Should ALL 3d photos be taken as parallel views, or is keystoning (centering a specific NEAR subject in both images (non-parallel views) have advantages in some cases? I have read that keystoning is bad...BUT, I've seen some awesome anaglyphs that had the DISTANT objects more greatly separated than the near ones....which seems contrary to the parallel-view method. What is going on?! I just got back a first batch of 3d anaglyphs, and most have problems, probably due to the picture-to-picture angle I used...WHAT is the correct technique for taking stereo pairs?! I can't find any clear reference to this anywhere, and I'm dying to know. More specifically, what is needed to have objects seem to pop out of the image plane? Longer baseline, keystoning, or simply nearer objects?


Thanks to anybody volunteering some info!

Adrian Schubert    (adrian.schubert@xxxxxxxxxxxx)


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