[MF3D.FORUM:1000] Re: Mounting tips?

["David W. Kesner" <drdave@xxxxxxxxxx>]

David Lee writes:

> If the window placement really affected the way the deviation was
> experienced by the viewer, then anytime there was an excessive deviation one
> would just have to mount it so that the excess was in fromt of the window.
> Discounting the problem of incorrect window placement this obviously could
> not be a solution to the problem, because the amount of deviation would not
> have changed.

Sorry David, but you are wrong here. Window placement can have 
an effect on deviation. If I had two film chips where the 
deviation between the near points is 2.0mm when the far points 
are homologous and I then mount (place the window way foward) 
so that the far points are 2.0mm apart it would spread the 
near points to 4.0mm. There is still only 2.0mm between the 
near and far points, but there is 4.0mm total deviation 
between homologous points.

This "technique" is used all the time by projectionists to 
reduce the excess deviation caused by enlargement on the 
screen. They simply move the chips (projector lenses) closer 
together which brings the scene through the window or off the 
screen as some prefer it to be called.

So yes, you could correct excess deviation by placing the 
excess in front of the window as long as the total on either 
side did not exceed your personal amount (2.0, 2.3, 2.7, etc.).

That's all for now,

David W. Kesner
Boise, Idaho, USA
drdave@xxxxxxxxxx