Hi Dale, It sounds like you are heading for Europe or the Near East this August and want to get the prominences this time? Just a thought ... does that lens have an IR correction mark? If so, that should give you an idea. By the way, I will be on the Vistafjord, in the Black Sea. This time I will be shooting with FM2n's instead of Pentax. Bill > Date: Wed, 10 Mar 1999 09:40:02 -0800 > From: "Dale Ireland" <[EMAIL PROTECTED]> > Subject: chromatic aberration graphs [v04.n294/21] > Message: 21 > > Hello > Could someone e-mail me or direct me to a source for a longitudinal > chromatic aberration graph for the Nikon 500 F/4 EDIF (manual focus) > I am especially interested in how far away from prime focus in um is the > focal point for 656.3nm > Thank you > Dale Ireland > Astronomy Page http://www.drdale.com > Comets, Satellites, Eclipses, Photography, Fabrications Bill Ronald, Vancouver, B.C. [EMAIL PROTECTED] Member - RASC Vancouver Centre 49:15:00 N : 123:10:40 W