Danny, You didn't mention the kind of gear you use; but it really dosen't matter what brand name happens to be on the lens. I've used Nikon & Canon myself, and of course there are many others. Anyway, I say this because not all lenses (even the same model) are created equal. I've been renting a 500mm Nikkor F4 whenever I need the long lens stuff and have had great results for not much money. It's usually available for me at a moments notice here in Kansas City, (unless the Chiefs are playing a home game!) I will probably buy this lens someday since I know it so well. The optics, sharpness, clarity, etc., of all lenses can vary and the only way to REALLY know value in a long lens is to take it out for a test drive. Focus and shoot the same subject under the same conditions (with a rock solid tripod) from every angle using the priorities, manual and AF, too. Try another lens and make the same tests. Then, look at the slides carefully, even make some prints. I work at a color offset printing company which also has a photo lab (very convenient) and I've found that "R" prints are better than "C" prints for test purposes since no interneg has to be make from the slide. You might want to try both types of prints from the same slide for another comparison study. Rail photography, like any visual art, is very, very subjective. We all see shots in magazines at times that make us clueless as to what made them worthy of publication; go figure. You might want to show your test results to others for comparison. Unless you make you're living as a professional (and maybe you do), I'd certainly consider renting a good pre-owned lens before shelling out many many $$$$thousands for a new one.
Wishing you good shooting in the new year! Bill Siegel -> SPORRS: Serious Photographers of Railroad Related Subjects -> Web Site: http://www.anet-stl.com/acphotog/sporrs
