Re: [ATM] source for mirrors/focusers/spiders

["Bob May" <bobmay@nethere.com>]

Probably the buggest reason for no comprensive sources is that it
costs only a few dollars more to assemble the parts and thus you
have another scope maker.  In addition, most of the producers of
the parts are more small time operators that are doing the
telescope stuff as an ajunct to there normal business.  Getting a
maker of focusers to also do spiders shouldn't be hard but it is
a different part with more choices for the construction of a
kit - tube diameter and secondary diameter for example.\
Prices on optics vqry widely because the quality of the figure
can vary widely between the various makers of optics.  Glass is
very particular at those accuracy levels and the ability of a
person do do the process also varies a lot.  There is definitely
a difference in quality between 1/4 and 1/8th wave optics as well
as whether that measurement is done on the wavefront or the
surface (1/2 the wavefront error). 1/8th wave on the wavefront is
4 time as accurate as 1/4th wave on the surface.
Bob May
bobmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net
Replace the obvious words with the proper character.

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