R.Acevedo,


Despite the examples of issues with the 15-85, I still recommend it. Really, it is part of "knowing your lens". The 15-85 is very good, not perfect. My experience is that thereis some barrel distortion at 15 mm (3.14% measured by photozone.de), but that it quickly goes away (24 mm they measured 0.581%). My experience the issues with vignetting and barrel distortion diminish by 18 mm (not measured by photozone.de). Also, for comparison to the other lens you mentioned, the 18-200 mm, photozone.demeasured 4.48% barrel distortion at 18 mm.


As a question for Stephen/others, is there more than one type of distortion going on inthe photo of Big Ben at 15 mm? It is certainly extreme. I am wondering ifpart of it is"convergence of parrallel lines"?A perspective issue?


Thanks,


Brant