From: "Jan van Gastel" 
To: 
Reply-To: "Jan van Gastel" 


A shorter focal length telescope will not collect more light, assuming the
same mirror diameter.
Visually, there is no difference between two equal aperture telescopes, at
the same magnification.
Fotografically, the shorter FL telescope of two equal aperture telescopes,
needs less exposure time for the same object under the same conditions.

Jan
http://home.wanadoo.nl/jhm.vangastel/Astronomy/
----- Original Message -----
From: "Arthur" 
To: ; 
Sent: Saturday, July 12, 2003 4:59 PM Subject: Re: ATM First Question



The shorter focal length telescopes collects more light,thus allowing you
to see fainter deep sky objects at high power. But, it's both the focal
length, and the size of the optics that make the shorter focal length most
desirable


Bill
-------Original Message-------

From: Steve Houlihan
Date: Friday, July 11, 2003 11:32:45 PM
To: atmlist
Subject: ATM First Question

Newbie Alert!

Does a short focal length have any advantages beyond making the scope shorter?

Steve Houlihan
Santa Cruz, California

sho{at}starband.net
http://sho.mystarband.net/
http://www.surfnetusa.com/sho



.

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