[toni-a]

I had also a 17-55 that was faulty, I had it replaced, the new sample was simply astonishing. You get what you pay for. Maybe Canon 15-85 if range is priority could do the thing. However for me f5.6 for a standard lens is a no no since I mostly do portraits and low light. A large aperture is not only important for the picture itself but also for focusing since focus needs light, unless in bright dailight you will have the focus hunting. One feature I like a lot with Canon 17-55 is it is a true parafocal lens, focus doesn't change when you zoom. Its only drawback is vignetting especially at 17mm 50D corrects this automatically though.

To be noted at 17mm this lens is truly 17mm I noticed it is much wider than other 18mm lenses, my guess others are just lying about focal length