RE: ATM Big Bad Cheap Lenses?

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

Thanks for all the ideas.   We actually started with a relay lens system
made from fresnel lenses spaced at 2f, but if if you use any more than four
fresnel lenses you start to get unacceptable degredations in quality. I said
that quality wasn't much of an issue, but I was thinking in terms of normal
optical standards, where you want to resolve the doubles in epsilon Lyrae or
whatever.

I am in fact using an infinite conjugate relay lens system now, which is
essentially two telescopes facing each other.  I should revisit that and try
making a small-lens finite conjugate relay system in between the Fresnel
lenses.  If I could use 3" lenses it would be easy to find ones of the right
focal length that aren't outrageously expensive.  I think though, that the
larger the lenses I can get, the better the viewing angles, which while not
critical, would be nice.  I will experiment this weekend using some 1"
lenses I have in my optics cabinet, but in the meantime, any lines on larger
but comparitively low quality bi convex lenses would be great.

I shall let you know.

Thanks,

Robin Coope
UBC Physics and Astronomy
Genome Technology Lab