Back to Home

General 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 | Misc. Topics | Post

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
If Your Collimation Is Off...

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Andy Kidd on October 12, 2002 17:04:15 UTC

IME one can get 'astigmatism' type effects such as only being able to get 'one side' of your FOV in focus at a time [also w/ an f5 scope coma (which you can't do anything about short of getting a paracorr) will start to come into effect- mostly away from the center of the field though].

IMO, 'masking', 'stopping down' or some form of reducing your aperture is mighty silly [unless just to remove a mirrors turned-down edge from the image (or in the event your mirror is of spherical figure rather than parabolic)]. If you want a smaller aperture or longer f-ratio scope- why not just get one [with a newt, 'stopping down' is NOT the same... the relative increase in obstruction % can become dramatically detrimental].

Jupiter being lower on the horizon IS, under the majority of conditions, going to make the 'seeing' of it worse [and probably nearly 'exponentially'- the amount of atmosphere one is looking through doesn't increase linearly as you drop in declination].

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