> I love it when you publish your test shots�they've played a part in > what I've bought, and haven't, ever since I got on the list a few years > ago. For me, when it comes to buying glass, a picture really is worth a > thousand words.
> Not having any zooms or any experience with zooms other than the > standard ick-zoom on my former brother-in-law's Canon Rebel, I have a > question. Since this ATX 100-300/4 is a high end zoom, is the fall off > on the corners and sides wide open over its focal range typical of most > zooms? > Dan Scott (Zoomless in San Antonio) Dear Zoomless: (<g>) Thanks for the test shot comments, Dan. I feel that even an embarrassingly simple low-res JPEG (with absolutely no esthetic value - <g>) might be useful to somebody out there, which is why I make such pretty dull looking photos available - <g>. As for the light fall-off, it's pretty typical on the 100-300/4, and might even be a little lower than average. Of course, ~all~ lenses (especially fast lenses) show some light fall-off wide open. In the Modern Photo review of this lens, the light fall-off values at 100mm and at 300mm (the only focal lengths tested for fall-off) were well under the allowable limits (100mm: allowable 1.1 stops, measured 0.6 stops; 300mm: allowable 1.0 stops, measured 0.5 stops). Of course, these are the values from f/4 - I know that at f/5.6 there is virtually no light fall-off, and the modest fall-off at f/4 would never be visible in images of most subjects anyway. Flavio mentioned earlier in this thread that the AT-X 100-300/4 is like a "300/4 lens (wrt weight size and quality) but with the option of zooming back too 100mm". That's a good description for this lens for me - it has remarkably uniform resolution and contrast throughout its range (unlike many longer zooms, where the lens often goes soft at the longer end). I probably end up using it zoomed to 300mm more often than to 100mm. Wide open, it gives the diminutive A* 300/4 prime a pretty good run for its money (although the F* 300/4.5 is sharper than either), which is not bad, considering its a zoom, after all. Fred
