Hi, Paul, If I'm not mistaken (and I may be) the Vivitar Series 1 3.8 24-48 constant aperture is the older of the two Series 1 that you mention, and it is also the sharper of the two. The other one is not constant aperture, I think it's 3.5-4.0, or something like that. It's not as good as the older one.
On the down side, the older, constant aperture one is big and heavy. I have it, and love it, though. I've not used the Pentax M 24-35, so I can't compare the two, but I can heartily endorse the Series 1 3.8 24-48; it's a wonderful lens (if you can get over the size and weight). If I'm wrong about the info in the first paragraph, someone can let me know. cheers, frank Paul Franklin Stregevsky wrote: > Erstwhile PDMLer and sharp-lens fanatic Shel Belinkoff wrote that this is > the zoom for people who don't like zooms. He prefers it to the Pentax 24-50 > f/4 PKA. It's the only zoom he uses regularly, and the build quality leaves > nothing to be desired. > > If the idea of a 24-35mm manual-focus zoom appeals to you, but not the idea > of spending $200 or more, you might want to explore some other options in > used glass: > > 20-40 f/2.7-3.5 Tamron two-touch (77mm filter) > 21-35 f/3.5-4.2 Sigma one-touch > 24-40 constant f/2.8 XR Rikenon two-touch (same as the Tokina AT-X below) > 24-40 constant f/2.8 Tokina AT-X two-touch; offers the PKA setting, unlike > the Rikenon > 24-45 f/3.8 (I think) by Soligor > 24-48 constant f/3.5 Vivitar Series 1 > 24-48 constant f/3.8 Vivitar Series 1 (not quite as sharp as the original > f/3.5) > 24-48 f/3.5-3.8 Tamron SP > > Some of these are available at surprisingly low prices; nearly all, > including the f/2.8s, usually cost less than the Pentax 24-35. However, most > are considerably larger and heavier. I have photos of all, if you're > interested, plus selected specs and collected comments for most. > > [EMAIL PROTECTED] > -- "The optimist thinks this is the best of all possible worlds. The pessimist fears it is true." -J. Robert Oppenheimer
