T3D Re: Tom's 1.2 mm question

[john bercovitz <bercov@xxxxxxxxxxx>]

> The significance of the 1.2 mm comes in projection.  Stereo
> projection is usually set so that (1.2 mm) x Magnification =
> 65 mm (or 2.5").  This is done so that the eyes would not have
> to diverge (as they would if this product was larger than the
> eye spacing).

I'm not sure I'm following you here, George.  I don't know very
much about projection but I assumed the idea was to make sure
infinity homologues were at about 2.5" so no one has to diverge.
Of course, if the audience is a long way from the screen, you 
can increase the separation above 2.5" because people _can_ 
diverge a little.  But for certain comfort, 2.5" would be the
limit.  

I can say all this and then I have to tell you that I think at
our club, the projectionists set the separation to taste.  8-)

I have more questions but I am getting very rusty on this stuff
and I have to get to a meeting right now.

John B


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