This is called a varifocal lens, as opposed to a parfocal. A varifocal require that you refocus when you change focal length. It can be a pain to use, but it allows greater flexibility in optical design. The Vivitar Series 1 28-105 was such a lens.
Brian Walsh wrote: A zoom? Nah--I hope it's a multi-focal length lens akin to the excellent Leitz Tri-Elmar (28-35-50) or the new Voightlander ultra-wide/35 in the Leica M mount. [EMAIL PROTECTED] -------------------------------------------------------------------- mail2web - Check your email from the web at http://mail2web.com/ . - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
