[Fwd: RE: rkymtmem-3d-digest V1 #193]

[Joel Alpers <rkymtmem@xxxxxxxx>]

Note: This reply came to "owner-rkymtmem-3d@xxxxxxxx" by mistake,
so I'm forwarding it to the list -

Joel.

-------- Original Message --------
Subject: RE: rkymtmem-3d-digest V1 #193
Date: Mon, 19 Apr 99 19:29:43 -0400
From: Virtual Imaging (John Vala) <vidi@xxxxxxxxxxxxx>
To: owner-rkymtmem-3d-digest@xxxxxxxx (rkymtmem-3d-digest)

Ron Sage writes:

>Tom Deering asked about projector lenses.

>The condensors should have the rounded parts facing each other.

>[) x (]    hopefully there is room for the heat absorbing glass x. Is it
>possible It could go

>[)(] x [)

>RDS


  My reply:  The light between the two curved surfaces of the 
condenser lenses is pretty much collimated and so has the lowest 
power density over the area of the lenses.  If placed in position #2
[)(] x [), the light is converging and makes for a higher power density 
that the filter has to contend with.  So optically, there is no
difference 
(for the most part) but, practically you will keep the glass from
breaking 
due to thermal stress if placed in position #1.


John Vala