Back to Home

ATM Forum Message

Forums: Atm · Astrophotography · Blackholes · Blackholes2 · CCD · Celestron · Domes · Education
Eyepieces · Meade · Misc. · God and Science · SETI · Software · UFO · XEphem
RSS Button

Home | Discussion Forums | Amateur Telescope Making | Post

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Robert May on July 25, 2003 17:30:53 UTC

You won't get truely spherical until you are polishing the glass. At 120 grit, the spherometer usually stays within a tenth of a thou. over the full surface and that is good enough at that point.
The big thing to remember is that at the finer grits, doing the light reflection test should end up with an even yellowing of the lamp across the width of the glass when you are nicely ground out and the frosting size is even all over the mirror without any zones of larger frosting.

Follow Ups:

    Login to Post
    Additional Information
    About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy
    Unless otherwise specified, web site content Copyright 1994-2024 John Huggins All Rights Reserved
    Forum posts are Copyright their authors as specified in the heading above the post.
    "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET"
    are trademarks of John Huggins