The greatest advancement in astronomy is probably the computer, for amateurs and professionals alike. Stacking images is now routine procedure for images published by amateurs. I'm coming to this software angle rather late in the game. Here are my first attempts using Comet Lovejoy as my target and the free software Registax:
Single 3-minute image, no processing
Stack of 4 images
What a fabulous sinkhole for my time that has just opened up!
I use this blog as a companion to my website www.brightstarstemeculavalley.org, where I call attention to local light pollution and share my enthusiasm for science and astronomy. I'm also a contributor to www.SkepticalScience.com.