Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site lanl.ARPA Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!genrad!teddy!panda!talcott!harvard!seismo!cmcl2!lanl!jlg From: jlg@lanl.ARPA Newsgroups: net.rec.photo Subject: Cometary telescopes Message-ID: <19336@lanl.ARPA> Date: Fri, 11-Jan-85 20:50:52 EST Article-I.D.: lanl.19336 Posted: Fri Jan 11 20:50:52 1985 Date-Received: Mon, 14-Jan-85 02:55:54 EST Sender: newsreader@lanl.ARPA Distribution: net Organization: Los Alamos National Laboratory Lines: 13 For amateur viewing of comets, a rich field reflector (or better yet - a Schmidt camera) should be used. Comet tails tend to cover a fairly large part of the sky and be very dim. To photograph them well, you need low magnifiaction and large light gathering ability. Professional Cometary research observatories use Schmidt cameras with VERY low f-numbers (1-1.4). I sent a more detailed statement to the original poster of this question to the net. Maybe he will summarize further responses later. ------------------------------------------------------------------------------ If the Earth were a grain of sand, we'd all be REALLY tiny! (*8 James Giles