{\rtf1\ansi\ansicpg1252\deff0\deflang1033{\fonttbl{\f0\fswiss\fcharset0 Arial;}} {\*\generator Msftedit 5.41.15.1503;}\viewkind4\uc1\pard\f0\fs20 This program illustrates the performance of the Mertz telescope and represents the first optical system to use procedural ray tracing tor analysis. The keyboard interface is:\par \par 1) First hit the F4 key to turn on the final output ray bundles at the image plane. There are 5 image points in the image field from 0 to 4 arc minute included field of view.\par \par 2) If you hit (toggle) the F3 key, the rest of the ray bundles in the telescope are presented (disabled.)\par \par 3) The F1 key toggles the opacity/transparency of the mirror surfaces.\par \par 4) The F2 key toggles a plot of the surface normal at the point of ray incidence on the mirrors.\par \par 5) The program always rotates, pans, and magnifies/minifies the telescope around the center point of the screen. So\par \par \tab a) the x,y,z keys rotate around their eponoymously named CRT axes Pressing the shift key first, reverses sense.\par \tab b) the arrow keys pan the telescope\par \tab c) the m key magnifies around the center point. Pressing the shift key first, reverses sense.\par \par 6) You can rotate the telescope around 2 axes by left clicking and dragging the mouse while the cursor is in the windows frame.\par \par 7) Hitting the r key always resets the view to original conditions.\par \par 8) Under Windows in the Task Bar, F1 spot diagram shows the intermediate image at the F1 plane after the rays are focused by the primary/secondary mirror combination.\par \par 9) Under Windows in the Task Bar, F2 spot diagram shows the final image plane. The green circle encompasses the on-axis ray bundle and gives the scale for the diffraction limited Airy disk size.\par \par \tab For 8)and 9) you can move the image plane forward/backward using the up/down arrows to see the effects of mis-focusing due to image plane mis-registration.\par }