[photo-3d] Re: curved projection screens

[Peter Homer <P.J.Homer@xxxxxxxxxxxxx>]

John A. Rupkalvis wrote in reply to my post

>Kodak actually offered purchasers of Carousel and Ektagraphic projectors a
>choice of either flat field or curved field lenses.   The reason, however,
>was because of the slide, and not the screen.
>
>If you projected glass-sandwiched slides, you wanted the flat field; if you
>projected uncovered slides, the curved field would be the better choice.

I am suprised that there would be that much curvature in unmounted slides unless they "Popped" under the heat. 

>I never saw mention of the effect of the Ektalite screen curve on edge
>sharpness.  Since true flat field lenses are hard to make (and expensive),
>it is likely that the curve did at least a partial compensation for
>conventional projection lens curvature (the Ektalite curve is in the right
>direction).
>
>Were your stereo slides mounted in glass?
  
I may have tried some of my earliest slides which were glassed but mostly I use unglassed RBT mounts, I dont remember any difference between any of my slides when I projected them with my FED and the screen curvature must have overcompensated any curve in the slides. I do not get the same distortion with the FED on a normal flat screen. P.J.Homer 

>Anybody else have any experience with this?