The first site allows the user to input different lenses and see what the beam divergence will be, good if you are thinking of changing the lenses in your pointer etc. The second site allows the user to input values that will determine such things as distance, divergence, power density etc.
http://www.lightmachinery.com/gausbeam.html
http://www.laservisuals.com/scanlite.php
http://www.lasershowsafety.com/
http://www.lightmachinery.com/gausbeam.html
http://www.laservisuals.com/scanlite.php
http://www.lasershowsafety.com/
