On Sep 21, 2006, at 6:57 PM, Shel Belinkoff wrote: > One complaint is that when zooming the lens it extends like the > 16-45, and > I'm not real thrilled about that. This "feature" made me wonder if > there > are zoom lenses that don't do that, and do all the moving of the > elements > internally. I guess you might call it an "internal zoom"
I also don't like the modern idiom of tromboning zooms very much, but they work fine. Fixed length zooms seem to be restricted to only the top end lenses, like the Canon 70-200/4L and /2.8L, and others like them. The Pentax F100-300/4.5-5.6 is a fixed length zoom with internal movement of the zooming elements, and front group focusing. That's why I like it more than the 80-320 as a design, although the latter out-performs it. Tromboning zooms always make me worry about element alignment and rigidity of the moving lens group, but I suppose that there's just as much movement in an internal zoom, you just can't see it. Godfrey -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
