Randy: > I bought a 105mm 2.5 Series One some years ago and at the time > noticed that its publihed test performance seemed generally > superior to the much older 90mm 2.5 Series One.
I haven't (yet) seen any test of the VS1 105/2.5. Do you have the details? Or, do you at least have the publication issue information? > That's to be expected with a design some 10+ years newer, a more > complex optical design and internal "zoom" type mechanics which > alter the element/group spacings as the lens is focussed to > maximize optical performance over the entire focus range, unlike > the 90mm 2.5. It would seem that Vivitar could improve on an old design from the 1970's, right? <g> However, I should point out that, in the VS1 90/2.5 Macro, the "internal "zoom" type mechanics which [also] alter the element/group spacings as the lens is focused to maximize optical performance over the entire focus range". I do have to admit that I don't know as much about the VS1 105/2.5 Macro's internal details (although I did own one for a time), and I can't say whether it does or does not have "a more complex optical design". In a sense, the inconvenience of the 90/2.5's 1:1 adapter might even be considered as an example of its own design complexity - <g>. > My 105mm Vivitar has performance sufficient for me to make 16x20 > inch prints from most of a full 35mm frame which compare favorably > against similar prints made from medium format negatives. I do have some scans of some macro test shots taken with the VS1 105/2.5 and the VS1 90/2.5 (and the AT-X 90/2.5, and the A 100/2.8, and the A 100/4, and the A* 200/4, and...]. While I have never blown any macro shots up to 16x20 (whew!), I have to say that all of these lenses do perform both really quite well and surprisingly also quite similarly. Comparing the prints side-by-side, I can occasionally find one lens may be just slightly better in one corner than another lens in that corner, but then I can often find the situation reversed in another corner (which probably shows more about my technique than it probably does about anything else - <g>). In any event, while I've recently put the scans of the VS1 and AT-X 90/2.5 "twins" on-line (with the URL's provided in another thread), I suppose I should get them all on-line...] Fred
