Some useful links. Note you won't be using a Koehler light source, but this might be of interest. http://www.micrographia.com/tutoria/micbasic/micbpt01/micb0100.htm http://micropix.home.comcast.net/~micropix/microsetup/ Parfocaling http://www.absoluteclarity.com/proper_user_set.htm -- cdb, colin@btech-online.co.uk on 16/04/2010 Web presence: www.btech-online.co.uk Hosted by: www.1and1.co.uk/?k_id=7988359 -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist