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 January 21, 2002 19:40:27 UTC

The direction of the lines depends upon the side of focus you are on. I generally prefer to do the Foucault test as you get to see the numbers of where the ROC is relative to the center of the mirror and you get quantitive results - no guessing if the curve radius of the lines are right but rather actual numbers of where the ROC is.
On a basically parabolic mirror, when the ends of the lines curve the same way as the lines, that's TDE while a hook the other way is TUE. Remember that with the parabolic mirror, the ROC is constantly increasing with the distance from the center of the mirror.

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 1994-2022 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