Tim TrottTim TrottA journey of a thousand miles begins with a single step


Collection of useful astronomy tools, calculators, reference guides and star charts to help with your astronomical observations and astrophotography.

Telescope Calculator
What's the optimum magnification for my instrument? Is the field of view of a given eyepiece too small to see all of the Moon? Is there a minimum magnification for my scope? What sort of limiting magnitude should I expect with an instrument of a given aperture? You can find answers to all these questions and many more besides with this interactive telescope calculator.
How To Calculate Star Trails
01/05/2009How-To Guides Tools
This star trails tool will give an estimate to how long an exposure you need for star trails to form at a given focal length and target declination.
Insanity is doing the same thing over and over again and expecting different results.Albert Einstein