Posted by Gary Poyner at 20:17 on 2010 Apr 15
Hi Paul,I’ve used Dobsonians for many years, and although I’ve been using a Meade 14 GPS for the past seven years, I’ll soon be returning to the joys of star hopping with a new 20 inch. I have been keeping my hand in with a 22cm dobbie as well though during this time.I observe variable stars – faint ones (CV’s to mag 16’ish) – from Birmingham. The best advice I can give is two-fold. Use the largest finder scope you can, and prepare your nights viewing with charts printed from one of the various planetarium software available. I use GUIDE 8, and would recommend this to anyone. It’s excellent for the faint fuzzies too. I would not recommend using a laptop – even in night mode – as this will affect your limiting magnitude. Just make sure you print the finder chart with the correct field orientation (Newtonian North to bottom, West to left), and remember that the stars drift towards the West. The finder is most important. 9×50 is OK, but a 10 or 12×60 is better. If you can get to mag 9 with your finder, you won’t have any trouble locating any object in the sky within a few minutes. Practice makes perfect of course, and after a short while you will be able to drop your scope on most fields without even looking. Good luck, and keep us posted as to how you get on.Gary