> Once you get into the world of MTF (modulation transfer function) > (wot's lenses got to do with modulation then ???) and its kin you are > in a brave new (or very old world) where people will pore over results > interminably. .... Yeah, I know, the optics guys here get all set up with their modelling soft= ware attempting to identify reflection patterns within lens systems, so the= y can cancel them out when looking at the stars ... How to make a space camera ... Get several lens made to spec, test them all, then select which ones you wa= nt to put together in one lens system, including rotation data for each len= s ... --=20 Scanned by iCritical. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .