P3D Re: Projection problem

[Tom Hubin <thubin@xxxxxxxxx>]

Greg Wageman wrote:

> the emulsion side faces away from the viewer's eyes both in
> projection and in hand viewing.  (The slide is simply rotated 180
> degrees to invert it for projection.)  This gives the correct right-left
> orientation, as originally photographed, in both presentation methods.

I have projected mono 2x2's and they were inverted with the emulsion
side toward the screen. At least I am pretty sure that is what I did. 

The emulsion side is the surface with the scene (object) to be
projected. It should be close to the projection lens. Then the slide
thickness is not between the object and the projection lens. This way
the slide thickness does not contribute to spherical aberration.

I find it hard to believe that the designers of projectors would want to
include the slide thickness and accept the resulting spherical
aberration. I know the projection lens can be designed with a particular
slide thickness in mind but then all film would have to be the same
thickness. That seems unlikely.

Can you point me to references on proper slide mounting and/or
projection. Mono and/or stereo. Not technique, just principles will do.

Tom Hubin
thubin@xxxxxxxxx