ATM

Various items relating to optical design and construction. All About Eyepiece Designs An overview of the basic concepts and a very complete guide to the various eyepiece designs available. Measuring Focal Lengths How to measure the focal lengths of positive and negative lenses and mirrors. So pull out that box of surplus optics and start labelling! Vignette (22kb) Gerald Pearson's Vignette program calulates diagonal size based on field illumination. C source code is included in the .zip file. ATM Calculator A JavaScript calculator for common telescope equations. Works with Netscape Navigator 3.0 or Microsoft Internet Explorer 3.0. Eyepiece Focal Plane Positions Where various popular eyepieces come to focus, also instructions for you to measure your own eyepieces - make sure to send me the numbers you get! A Trip to Liebmann Optical A field trip to a professional optics firm. Interactive Ray Tracing (298kb) This is an early release of IRT for Windows. IRT is a full capability geometric raytracing package, suitable for development and analysis of both simple and complex optical instruments. Baffling Newtonains... A step-by-step guide to sizing and locating baffles to improve contrast in Newtonian reflectors. ...Or Not Baffling Newtonains An opposing viewpoint for improving contrast in Newtonian reflectors without baffles.