ATM Big Bad Cheap Lenses?

[Robin Coope <rcoope@physics.ubc.ca>]

Hello all from a new member

I'm helping with an art installation consisting of three 1x telescopes -
really image guides - which are about 24" dia x 12-16 feet long.  I've
designed optics with two Fresnel lenses at the ends and two bi convex lenses
inside.  To make this work I need 6-10" diameter leses with a focal length
of about 60".  I'd like to use more fresnel lenses but they all have a focal
ratio of about 1 which is too short.  Image quality is not an issue, the
lenses can be uncoated and/or plastic or whatever.  Cost obviously is an
issue.

Can anyone give me any advice or leads on where I might be able to find such
lenses?

Thanks in advance and see me if you need advice on building your own
scanning tunneling electron microsope,

Robin Coope
UBC Physics and Astronomy
Genome Technology Lab