Back to Home

Eyepieces 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 | Eyepieces | Post
Login

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

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Daniel Johnson on January 31, 2003 22:05:01 UTC

For long-focal-length eyepieces that show a field of view that occupies the entire physical barrel of the eyepiece, a 2-inch diagonal helps. With such eyepieces (most 32mm or longer Plossls, or the new TeleVue 24mm Panoptic, for example) the eyepiece barrel itself serves as the field stop. You don't want anything that is 1.25 inches or narrower anywhere earlier in the light path prior to the eyepiece, since it would cause vignetting. However, for high-magnification eyepieces (with smaller fields of view), there's little or no difference between a 1.25" or a 2" diagonal.

--Dan Johnson

Follow Ups:

    Login to Post
    Additional Information
    Google
     
    Web www.astronomy.net
    DayNightLine
    About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy
    Unless otherwise specified, web site content Copyright 1994-2018 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