Telescopes that are hauled across the landscape to observing sites away from home get out of alignment, or collimation. Getting things back in order is part of the job of observing. Some telescopes such as Maksutov-Cassegrains with a silvered secondary and refractors tend to keep collimation almost forever (unless mistreated). Other types need to be checked and adjusted sometimes every time that they are used. This little paper will discusss Newtonian type reflectors.
Your local chapter of the Royal Astronomical Society of Canada
