Re: perfect slide mounting

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

>What is "mounting for the stereo window?"  I assume it doesn't mean mounting
>so that objects at infinity are aligned exactly the same way in the mask
>(mounting for infinity, right?), and it doesn't mean that the closest
>objects are aligned exactly the same way in the mask (mounting for...the
>closest objects?).  

What does "aligned exactly the same way in the mask" mean?  Constant
separation?  When you mount for infinity you have one clear objective: 
Place the chips in the mount so the infinity points have the same
separation.  Mounting for the window does not have any clear objective.
You mount the chips so that the stereo window is wherever you feel it looks
best (and the infinity separation changes from slide to slide).  Sometimes
you might feel that the closest object should be at window level (perhaps
what you have in mind with "mounting for closest objects") or perhaps just
behind it, or, possibly, in front of it.  It is a subjective call.

>So what is it, something in between?  And if so, how can
>you avoid adjustment between slides?

What kind of adjustment do you have in mind?  Adjustment of the
horizontal separation?  Why?   The projector is adjusted to have the
mask overlapping in the screen and, consequently, the stereo window at
screen level.  This does not change from slide to slide. What changes is
how the scene is positioned with respect to the window.  That might lead 
to a change in the corvergence from slide to slide when looking at infinity
and this is the main objection of those who prefer the infinity mounting.
But changes in convergence are generally harmless.  Plus, not every slide
is a nice scenic with clear infinity.  Once you know what you are doing
I believe you can mount slides succesfully without using a constant
infinity and these slides will look better.

To answer your question, no, I do not see why you need any adjustments.

-- George Themelis


------------------------------