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Old 17-07-2017, 05:56 PM
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OzEclipse (Joe Cali)
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Join Date: Jun 2012
Location: Young Hilltops LGA, Australia
Posts: 1,185
Quote:
Originally Posted by hamishbarker View Post
Forgot to add, i plan to install a compter fan blowing across the front of the mirror a la Alan Adler's sky and telescope article for better cooling and warm boundary layer elimination.

I also have a 200mm f3.75 spherical mirror from aliexpress which i bought thinking it was focal length of 750mm rather than what it actually is, radius of curvature. I might try to parabolize it for figuring learning and then build as a wide field scope maybe astroscan style to be durable for my son. Or maybe is that just too fast and difficult a job?
That is a hell of a mirror to use to learn how to figure! The re-aluminizing will cost you more than a new fully figured 8" f4 mirror from GSO will cost.
A new 8"f4 GSO is $219. I suggest you teach yourself mirror figuring on the Aldi mirror but don't re-aluminize it. Spend the re-coating budget on a new GSO mirror and use the change to buy some of the other bits and pieces then make him a telescope wrapped around a decent GSO optic.

Good luck whatever you do.
Joe
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