Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site decwrl.DEC.COM Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!decwrl!dec-rhea!dec-nrlabs!naticchioni From: naticchioni@nrlabs.DEC Newsgroups: net.astro Subject: Large apertutre vs. small for nebular seeing Message-ID: <1045@decwrl.DEC.COM> Date: Tue, 11-Feb-86 07:34:19 EST Article-I.D.: decwrl.1045 Posted: Tue Feb 11 07:34:19 1986 Date-Received: Wed, 12-Feb-86 21:20:02 EST Sender: daemon@decwrl.DEC.COM Organization: Digital Equipment Corporation Lines: 37 NEWSGROUP: net.astro PATH: decwrl! SUBJECT: Deep Sky Viewing Telescope. POSTED: February 7, 1986 ORGANIZATION: Digitial Equipment Corp. Design & Evaluation Lab, Norhtboro, Ma. I AM INTERESTED IN BUILDING A 13 TO 14 IN REFLECTING TELESCOPE FOR DEEP SKY VIEWING OF NEBULARS. I HAVE A 4.25" F/10 NEWTONIAN THAT I USE NOW FROM 35X TO 200X BUT WOULD LIKE A WIDER FIELD OF VIEW AND A BRIGHTER IMAGE. THERE ARE SEVERAL COMPANIES THAT SELL LIGHTWEIGHT 1/8 WAVE MIRRORS AT F/4.5 TO F/6 AND THEY CLAIM THIS IS WHAT I WANT. I AM HOPING TO KEEP THE COST OF THE SYSTEM BOTH IN TIME AND MONEY MINIMAL BUT STILL HAVE A GOOD VIEW. THE SHORT FOCUS NEWTONIAN SEEMS TO BE THE WAY TO GO BUT I HAVE BEEN READING THAT A SMALLER MORE ACCURATE MIRROR WITH A LONGER F RATIO IS BETTER. IS THERE A TRADE OFF POINT IN SIZE, ACCURACY, AND F RATIO? I WOULD LIKE ANY RECOMENDATION ON WHAT OTHERS HAVE USE AND WHY? IS THERE ANY GOOD REFERENCES I COULD USE? ANY DATA OR FORMULAS WOULD ALSO BE APPRECATED. THANKYOU FOR YOUR HELP STEVEN M. NATICCHIONI DIGITAL EQUIPMENT CORP. NRO5/F2 30 FORBES ROAD NORTHBORO, MA 01532 (617) 351-4862 P.S. "A LITTLE EXPERIENCE REPLACES A LOT OF THEORY!" NRLABS::NATICCHIONI