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
RE: Trade It Or Save It!

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Rick Crockett on March 16, 2000 20:26:22 UTC

Hi Anthony:

Do not try to regrind. That mirror has a value far greater than the blank which is all that it is if you regrind. Even then it is not really a good start for a variety of reasons that would take too much page.
As fast as it is, I doubt that it is a paraboloid, especially if it is not perforated. If used as a Schmidt camera (lensless if it is a paraboloid) it still is only about 80mm of focal lenght and as fast as it is any wobble in the mount would be unforgivable as the bright star will definately trail. Still on a good mount and with care in un capping, this is probably you most reasonable use.
What you would do is place a 4" to 4.5" aperture stop at the radius of curvature. There are some old articles in S&T about lensless Schmidts. You probably will need to make a curved plane filmholder and the curve probably will depend on the conic type of your mirror.

I believe this is the only practicle use for that fast a f-ratio but it might also have an application as a relay element in some form of off-axis reflector or hybred.

Good Luck and Have Fun,

Keep it as a novelty, trade to some one else that can find a value in it but don`t regrind it.

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