It does emphasize the softness at e.g. 17mm f/4 but you'd notice that on the lower-resolution sensor too. I don't use UV filters; one particular problem is that UV filter + polarizer on that lens impinges into the image frame and taking the polarizer on and off is enough hassle without moving the filter too.
The Jessops in town had the 50D and the 17-85mm IIRC though in fact I'd brought mine so I could try it with that.
no subject
It does emphasize the softness at e.g. 17mm f/4 but you'd notice that on the lower-resolution sensor too. I don't use UV filters; one particular problem is that UV filter + polarizer on that lens impinges into the image frame and taking the polarizer on and off is enough hassle without moving the filter too.
The Jessops in town had the 50D and the 17-85mm IIRC though in fact I'd brought mine so I could try it with that.