P3D Re: horizontal projection adjustment

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

Paul Baker writes:
   
>Apart from the fact that slight vertical adjustment is usually always
>needed when running slides mounted in different brands of mounts.

The key word is "slight".  If it is slight, then why is it needed?

(I personally do not see any difference in vertical adjustement when
I switch from RBTs to Albions or during projections in Detroit and
Cleveland where a variety of mounts are used so I am not sure if your
statement is correct or not)

>I tend to always adjust so the windows
>overlap EXACTLY, for two reasons:  I feel the window should be in the
>plane of the screen, and when there's intentional "through-the-window"
>effect this is the way to maximize it.  But most others in my club seem
>to try to go 50/50 on the horizontals, between the window and a distant
>point, which frankly I don't understand and don't feel produces the best
>presentation.  So, what the "correct" way?

I don't understand the club's practice...  It is better to talk about
infinity separation:  Do they increase it or decrease it?  If they
decrease it then they are bringing the stereo window in front of the
screen.  The extreme is to have the infinity points overlapping on
the screen.  That's a bad situation, IMO, but sometimes projectionist
tend to reduce the infinity separation either because they are 
projecting on a large screen and want to maintain a 2.5" infinity
separation or they try to reduce ghosting by matching the highlights.
For screens up to 70" that I have used, I have always put the stereo
window on the screen, and I agree that this produces the best results
for me too.

-- George Themelis


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