22 Apr
2005
22 Apr
'05
2:33 a.m.
On Apr 21 2005, 21:55, John Foust wrote:
It doesn't make any difference to the focussing of the scanner optics
whether it's seeing an image produced by light reflected from a plane,
or light from some other source producing an image in that same plane.
--
Pete Peter Turnbull
Network Manager
University of York
At 07:21 PM 4/21/2005, you wrote:
>You could just remove the fiche viewer screen. You don't need the
>screen to form the image, you only need the (virtual) image from the
>viewer's lens system to be focussed in the same plane as the
scanner's
optics.
Actually, since the image is usually focussed on the back
surface of the viewer screen, you'd want to remove it anyway.
Pointing the scanner at the plane in space that happens to be the
viewing plane of the fiche viewer isn't going to result in an image.
The scanner wants to see reflected light. Focusing the fiche
projection at the scanner's sensor is a different sort of problem
that would involve changing the scanner's optics, no?