This is my first time posting to the Canon Rumors forum, and I had an issue with a lens that I wanted to get some insight into and some advice on.
I purchased a refurbished EF-S 10-22mm wide angle lens a year or two ago from the Canon Refurbished store. I've been using the lens pretty regularly since I bought it. Recently I've noticed that the left side of pictures taken with the lens are really very soft, even stopped down (f 8 or 11 or so), and even when objects on the right sight of the picture (that are within the same plane) are sharper and in focus. I don't see the problem in earlier photos taken with the lens, and it does not require pixel-peeping to see the problem in the more recent pictures. I have never dropped the lens, and generally keep it stored in my camera bag, so if some sort of damage did occur I'm not sure what it would have been.
I know that wide angle lenses tend to lose resolution towards the edges and corners of the frame, but it is really the difference between the two sides of the images that leads me to believe it may be some sort of other problem.
Anyway, to get to the point, I was wondering: 1. What sort of defect or damage causes the sort of problem I'm describing? and 2. Has anyone sent a lens with a problem such as this to Canon and had it successfully repaired (and if so, do you recall about how much the repair cost)?
Thank you all for your help and advice!