Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site pyuxt.UUCP Path: utzoo!watmath!clyde!burl!ulysses!gamma!pyuxww!pyuxt!marcus From: marcus@pyuxt.UUCP (M. G. Hand) Newsgroups: net.rec.photo Subject: Re: lenses are sharpest at medium aperture Message-ID: <132@pyuxt.UUCP> Date: Sat, 9-Jun-84 14:42:06 EDT Article-I.D.: pyuxt.132 Posted: Sat Jun 9 14:42:06 1984 Date-Received: Sun, 10-Jun-84 01:17:49 EDT References: <757@hammer.UUCP> Organization: Bell Communications Research, Piscataway N.J. Lines: 13Optimum sharpness aperture depends entirely on the design of the lens. Since with most lenses the designers strive towards a fast lens (ie one that has a large maximum aperture wrt its focal length, in this context), and since most photographs are taken somewhere in the middle of the f-stop range, the designers compromise somewhere in the middle, although it is *easier* to make a lens whose maximum sharpness falls at the small aperture end of the scale because you don't have to worry so much about spherical aberation, edge effects, internal reflections and all that bad stuff..... marcus hand (pyuxt!marcus)