On Sun, 9 Nov 2003 16:11:34 -0500, J. C. O'Connell wrote: > With full frame 35mm, even a 1000mm lens wont fill the frame so > 300mm is definately too short for lunar photography.
One hundred millimeters focal length per one millimeter on-negative size, approximately. A 400mm lens with two 2X t/c's gives approximately 2/3 full frame vertically on 35mm film. TTYL, DougF KG4LMZ