[net.astro] Use Caution if purchasing an Astroscan

canopus@amdahl.UUCP (Alpha Carinae) (07/08/85)

Recently, a good friend of mine who owns an optical coating business
replaced, or attempted to replace, the aluminum coating on the Edmund
Astroscan RFT.  It turns out that the parabolic curve on the reflective
surface was generated NOT by parabolizing the mirror, but rather by
the aluminizing process itself.  Therefore, if you strip the coating
you have also stripped the figure!

While aluminized and overcoated mirrors should last a relatively long
time (up to 10 years?), potential buyers of an Astroscan may wish to
take this bit of info into account before making their purchase.

I haven't checked with Edmund Scientific to see if they will "refigure"
Astroscans... but they must be able to.  Anyone know for sure?
-- 
Frank Dibbell     (408-746-6493)     ...!{ihnp4,cbosgd,sun}!amdahl!canopus
Amdahl Corporation, Sunnyvale CA     [This is the obligatory disclaimer..]
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