New Second Edition now is stock! Richard Berry says in the forward to the second edition of Star Testing Astronomical Telescopes, Star Testing is a resource that should be on the shelf where you keep your most-often-used astronomy books. Toss it into your observing kit along with eyepieces, Oreo cookies, and packs of instant hot chocolate. Read it; absorb it; read it again. Star testing is an integral part of observing. If your telescope has properly adjusted and excellent optics, the star test will confirm that fact—and you are free to turn your attention to observing the splendors of the heavens. This book is highly recommended for anyone wishing to test and improve the performance of their telescope. For people frustrated with the inaccurate guesses, half truths and downright twaddle proffered on internet forums Suiter's book is like a shaft of light from the heavens illuminating a subject that is simple yet poorly understood. An invaluable addition to the library of every amateur astronomer. Many observers harbor misgivings about their telescope. The manufacturer may have guaranteed accuracy to one-quarter wavelength or as diffraction-limited but most telescope users have, at best, only a hazy idea of how to personally verifying such claims. Sure, there are ways to check the accuracy of individual components but for many they are hard to understand or require costly reference optics and other test equipment. Besides, telescope users are interested in the performance of the entire optical train, not just the main optical element. What is really needed is a test that can be used at the observing site, so that all the problems that impact on a telescope's performance can be diagnosed. Isn't there a simpler and more complete way than the complicated shop tests? Yes, the star test is such a method. It uses the entire working telescope. It is not a poor substitute or a work-around that uses bits and pieces of the optical system. It is the oldest and most sensitive of the optical tests—an inspection of the diffraction image itself. Star-test results apply to the complete imaging performance of the telescope. The star test is lightning-fast and requires only a good high-power eyepiece. It tests the telescope for precisely what it was meant to do. Bad or poorly-aligned instruments fail the star test unambiguously. The star test often allows you to correct the optical difficulty immediately in the field, when you might be frantic to have your telescope perform well to observe a once in a lifetime event. While the star test has been around for centuries learning it has often been hampered by messy mathematics and its visual nature. Most people who use it have learned it at the elbow of a patient Master. In this book, Dick Suiter becomes your Master. He carefully shields you from difficult diffraction theory and uses advanced computer generated graphics to show you the appearance of each aberration. Again and again, you will look at Dick's graphics and say I've seen that before. So that's what it was! The star test is a powerful but inexpensive way of obtaining better resolution and contrast. With this book most observers will find that they don't need a new telescope because they now can test, diagnose and fix the one they have. Using Star Testing Astronomical Telescopes as a guide, your telescope will perform to the best of it's abilities and perhaps it will show images better than you would have believed possible.