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
Login

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
Re: RE: RE: Upgrading From Meade 4.5

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Art Brown on November 4, 2000 15:43:46 UTC

Resolution and Definition.

These qualitites determine the sharpness of a telescopic image. Resolution is the ability to separate or resolve two adjacent point images. Definition is the clarity of extended images. Extended images include the surface of the moon, planets, etc. All stars are point images.

Resolution depends on aperture. The only way to improve resolution is to increase the aperature of the telescope. If you double the size of your telscope lens or mirror, you improve resolution twofold.

Definition depends to some extent on resolution, but also on the overall quality of the optics.

Also, there are limits to a telescopes capacity for magnification. The upper limit depends mostly on aperature. If you magnify an image too much, it becomes fuzzy and/or to dim to see. The general rule for extimating a telescopes upper limit of magnification is 60x per inch of aperature. Therefore a 2" telescope basically has an upper limit of magnification of 120x, a 6" is 360x, 8" 480x, etc.

A lot of factors enter into how much magnification you can find useful at any given time, such as air turbulence, quality of optics, etc.

Deciding on what size telescope to purchase involves a lot of factors such as portability, cost, where you will use it, etc. The best telescope you can buy, is the one that you will use. There are a lot of big scopes sitting in closets because they are to big to handle easily.

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 1994-2020 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