Amazing value and simply insanely fun lens for us who love the wide angle.
This is a lens should be chosen for its ability to go to 10mm (= 15mm on DX), then such a wide angle through natural law imposes certain limitations in lens design and performance, avoiding at longer focal lengths, while a 10mm lens has the very good performance.
Like other wide-angle lens that is best in the middle and becomes a little darker, a little fuzzier and get a bit more chromatic aberration towards the edges. However, this has no impact on the ability to create impressive images.
The lens lacks image stabilization, but due the short focal length, it is not impossible to hand hold down to a one-second exposure time. (One should take a series of pictures and then choose the sharpest.)