As promised here is one of the shots taken with my old Canon 400D and the 300 f/2.8. The combination of the two looks absolutely hysterical and entirely useless. Unless you are sat in your hide with the lens mounted on a sturdy tripod that is. The minute my 7D gets back from its repair I can guarantee, I will be out there making the most of it. I also borrowed a friend's 50D to see how that performed on the lens, it was obviously a great improvement over the 400D, the Herring Gull below was taken with this combination.