Objective managed

Without a doubt.
I now use for a month, and after 400 pictures with the stone in a variety of circumstances (night, bright sunshine Sky, gray and rainy, dark and bright inside), it never failed me.
After 2000 pictures, fun is always in style. I review my notes on the rise, as the little extras are little. Used in conditions of extreme contrasts, high brightness and night, that goal has never wavered. Debuting in the photo there three months, I did not get to control so the object.
The results are very good from f2.8. Its size is impressive, but it goes with the perspective of 72 diameter. The sharpness is very good, and very nice bokeh, and despite the conditions, I have NEVER had any chromatic aberrations (purple fringing and other, or else, it makes up very well to development). To signal that the focus ring is turned "AF" mode, and it is not recommended that the focus manually if you have not moved the cursor to "MF", simply because you would force on the engine and thus become damaged autofocus. Moreover, as this is a wide angle, can be found perspective deformations, which is quite normal for such purpose.
The development works very well, except in low light or she becomes a little slow (see plant completely) but this is far from insurmountable. The stabilization works very well in low light conditions (I only use it in this case), I will put pictures of example later. Coupled with a polarizing filter, it is a joy.
The zoom ring is a bit hard, but at least it guarantees easy control. The manual focus is a little more flexible.

I'm really satisfied with this objective.

Used on a Canon EOS 550D.