You will gain experience in using your telescope especially if you direct your attention to the main points of quality. You will find in time that you will become critical of imperfections of your telescope, casual or inherent. When you test your telescope's optics, you should be careful and pay close attention to your own eyesight and be guided by proper directions and only then will you have a good idea of the quality of your telescope. Remember that no telescope will give the most perfect image. Your telescope is good when you can see fine definition and not to worry about the out of focus star image. If there seems to be a problem with the telescope because of the star image, you can not say what the problem is until you make an examination of the out-of-focus image on a night fine enough to allow you to make a star test at high power, unless the fault is because of a astigmatism, maladjustment, or centering of the optics and on a good night these can be seen at focus.
Subject: MY THOUGHTS ON TESTING A TELESCOPE - Loron Knowlen 
Wed May 18, 2011 9:20 am
