P3D Projector manipulation? No, thanks!

["Dr. George A. Themelis" <DrT-3d@xxxxxxx>]

>Either the projectionist will be constantly adjusting 
>the vertical, horizontal, and focus to provide the 
>best, least uncomfortable view possible or there
>will be no adjustment and the audience will have to 
>suffer with unfusable, out of focus, or misaligned 
>images.

NONSENSE with capital letters!  I use at least three
different mounts and only adjust the focusing in my
stereo projections.  I attend the Detroit and
Cleveland club where in the competitions (slides
entered are mounted in different mounting systems)
only the focus is adjusted.  And these are the most
comfortable projections I have ever attended. 
And then there are the situations where the 
projectionist try to adjust the projector for 
every projected slide and then we all suffer from 
this projector overmanipulation.

What you are saying just gives excuses to incompetent
projectionists to torture us ("but these slides are
mounted in all different mounts... so we'll have to
adjust the projector for every individual slide.")

The projector has three adjustments:  Focus, vertical
and horizontal.  Most mounts (minus the defectives, and
please do not use defective batches of mounts as an
example to justify this bad practice) confirm to certain
standards.  To discuss each adjustment individually:

1. Vertical:  All mounts (minus defective) provide
vertical alignment.  Vertical misalignments come from
bad mounting.  

2. Horizontal:  Most mounts follow a certain
specification for the separation of the apertures.
There is a small difference between different mounts
(I have noticed this when comparing the Albions and
the RBTs) but this small difference does not justify
adjusting the horizontal control IMO.  There are two
more reasons to adjust this:  To reduce on-screen
deviation (a result of bad mounting) or to reduce/
eliminate ghosting (very bad practice!).

3. Focus:  Yes, slides of different thicknesses 
require refocusing.  This adjustment is necessary and 
harmless.  It even helps an image to bring it to focus. 
"Ahhhhh..." says the audience..., not "ouch!".

There! I proved my point:  Projection overmanipulation
is not justified by the variety of existing mounts.

George Themelis

PS. Last time we discussed this, I was nicknamed
"DrT, Dictator of 3D"... I hope you understand why...