P3D Re: Projection problem

[Oliver Dean <3d-image@xxxxxxxxxxxxxx>]

Hi, Tom!

Tom Hubin wrote:
> If you stand behind the projector wearing viewing glasses then remove
> the glasses and place them over the projector, as if the projector is
> your face, with the earpieces pointed toward the rear of the projector,
> and the right lens over the right projector, the image should pass. If
> the image is blocked then the right and left polarizers need to be
> swapped or you need to be happy with pseudo 3d.

Sorry, Tom! You have it just backwards!  To make sure, I just tested
this with both my Compco 500 and my TDC 716 projectors. What you say
sounds logical, but it doesn't work that way!  What you're forgetting is
that, because the slide must be projected inverted, this also switches
the position of the left and right views in the projector, so that the
right-eye view is being projected through the left lens, and the left
eye view is being projected through the right lens.  With the glasses
oriented as you describe, the left polarizer of the glasses is being
positioned in front of the lens projecting the right-eye view, and
vice-versa. 

Accordingly, when you run your test as you describe, the images should
be blocked if the projector's polarizers are correctly oriented, and the
images should pass if the projector's polarizers are pseudo.  Regardless
of the correctness or incorrectness of my explanation, this is the
TESTED result you should get.  Your clearly described idea was great for
a simple test -- it just needed to be checked out first!

Cordially,
Oliver Dean