In the August 2012 Sky & Telescope
In this issue's Binocular Highlights column it’s time to sweep up a pair of neglected-but-nice Sagittarius open clusters. So rich are the Milky Way fields found in this region that M23 and M25 rarely get the attention they deserve.
Based on my years of building and using telescopes I’ve come up with a list of the five biggest Newtonian reflector performance killers. In this month's Telescope Workshop I describe how you can overcome them and get the very best performance from your scope..