Re: ATM Big Bad Cheap Lenses?

[Del Stanton <sd20@earthlink.net>]

Edmund Scientific:

11 x 0.17"/13.0" FL Lens
                                   A fresnel lens is a
thin, flat piece of acrylic or similar
                                   material in which
are molded a series of small
                                   concentric stepped
zones. 
                                   CR30531-26 - $14.95 

URL: 
http://www.ScientificsOnline.com/Products/ListProducts.cfm?catid=178

DEl Stanton  sd20@earthlink.net

Robin Coope wrote:
> 
> 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