Canon Service Center - Great Results!

Unfortunately, a year or so back, I dropped my Canon 100-400mm IS lens, and while it didn't hit the ground hard, the filter shattered which in the end resulted in a very small nick in the external glass of the lens. The rest of the lens appeared to still function fine, but after months of use, I noticed that when IS (image stabilization) was engaged, the auto-focus was way too soft. In time, I stopped using the IS. After hearing that Canon's Service center did a nice repair job for a friend of mine, I decided to try them too. Sure enough, I'm very happy with the results.

Go to Canon's web site, surf to the support page for the EOS cameras and ask for a quote. Since my lens was out of warranty, they were not able to quote a repair price, but they said if I mailed it to them (at my cost) they would email me with the cost of the repair, and on my approval they would perform the repair in 7 days, and return it to me at their cost. If I didn't like the repair cost, they would also return it to me at their cost. The repair cost was reasonable, given what they probably had to do to fix the IS and auto-focus, and they also replaced the front glass, and shipped it back, and it works great! I recommend this same approach if you are not happy with the performance of your lenses too!