I highly recommend this objo and I do not regret at all despite my hesitation from the fact that it is not precisely stabilized and even 200 in a so rather dark theater without flash and I have 80% of my photos that are more than adequate or even excellent for my relatives who have seen the photos but a second parameter is also taken into account, the case which manages more or less the rise ISO (EOS 550D for me) while I know that a 2.8 L 70/200 would have been welcome in this case but it is not the same price ....
Outside I don not even speak, if == finally just breathtaking.
rather prefer replacing your goal rather than the housing in some cases.
do not forget to stick him HTMC UV filter to protect the lens.
that is all there is.