Given a lens and a source-image at a known distance away from the lens, I'd   
   like to know what the lensed source looks like at different positions (for   
   example, in case of a real image, I'd like to know what the lensed image looks   
   like on a screen    
   positioned on the other side of the lens.)   
      
   Are there any geometric-optics software that do this?   
      
   Regards,   
   Siavash   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)