baffle placement refractor

http://www.berfield.com/baffles.html
http://www.berfield.com/okapi.html
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/2946940/Main/2943927
http://www.otterstedt.de/wiki/index.php/Blende_(Refraktor)