Here is a review left by a customer on a product. Would you say he was satisfied or dissatisfied?
Title: Unhappy :-(
Review: I bought this lens over a year ago with great expectations. I used it a lot but was not impressed with the images near 200mm and wide open. I was told that this lens does have a steep learning curve so I persisted.I decided to check for back/front focusing. I focused on the center line (Camera on tripod, IS off, Mirror lockup, manual focus with live view on 40D). The focus was centered on the "Focus Here" Line but it was not sharp. I had to zoom down to about 135mm @ f5.6 to get sharp focus. I was impressed with that sharpness, but I didn't pay for a 135mm f5.6 lens!I sent the lens to Canon for service and they said it was front focusing and they "made an adjustment". No difference as far as I could see. I truely had a bad copy but couldn't get it replaced after 30 days.I sold the lens and bought a 24-105 f/4L and couldn't be happier. I'm considering the 100-400 for my next purchase. I realize my experience is exceptional (In a bad way!), and hopefully you will have better luck.
