Re: ATM 90mm f-11 APO

[mike coslo <mjc5@psu.edu>]

	What I suggest is that you check out the Newport glass website. They
have kits for making refractors. No APO's but no expensive glass costs
either. I don't know the exact prices of Flourite glass, but I do know
it isn't cheap. A Triplet is quite a design process also. A nice
achromat might be able to fulfill your scope building lust for a while.

	- mike -

	

Brian Boothman wrote:
> 
>   I am still in the contemplation stage of this project.
> I was thinking that at only 90mm the glass could not be
> all that expensive. Perhaps I was wrong.
>  I was thinking of a refractor because I am limited to
> a small space and the mess associated with a large mirror
> is not an option in my location.
>  I understand that a lens can be more difficult in many ways
> than a mirror. But easier in some. Wedge and thickness are
> a factor with a lens but the surfaces are spherical
>  Testing is more difficult, the surfaces are smaller and
> more numerous.
> 
>  How much could 3 pieces of 90mm glass cost?