"Used only outdoors, like the moisture and dust sealing."3.0 starson by RainerRo
Pros: Pros: Outstanding optical Quality. replaced my old, bulky and heavy 100-400. Using with 1.4 extender and some cropping to get similar results!
Cons: Mechanically anything but Pro-quality. Banged it slightly against a ship railing and a retaining ring inside broke, rendering the lens totally useless. The solid lens barrel did not show any sign of damage. Excellent outside, lousy inside.
Summary: Be careful when carrying this lens around. It may also be a good idea to have the camera turned off when not in use.
Also remember: repairs are expensive and if you do have to send it in it will take some time.