bought this lens with some apprehension. I'm a bit of a purist when it comes to my lens collection and apart from one Sigma item I only own Canon glass. I own a Canon 550D and have never felt I could get a wide enough lens (that was also compatible with a full frame camera) for a reasonable price. A friend of mine owns the Canon equivalent of this device and it has always made me jealous. Since it's only about 15% the price of a Canon lens, I didn't have high hopes for the quality of the stills (or movies) this thing would be capable of. How wrong could I have been. For the money, this lens is just amazing. Wide but also very sharp at 100% crop. I am quite amazed at how good this product actually is. At this point (a week of extensive testing) I don't regret buying this lens at all. It works very well for pictures and videos (which is what I mainly use my camera for). Build quality feels solid, my only downside is that the focus ring on my device is a little rough in places. I also don't think this unit will stand the test of time as well as my Canons, although I'm not sure why I think so. In fact, using the lens is also a bit more complicated than its more expensive counterparts - as you've noticed in the description is the full manual; focus and aperture. I can understand that this isn't for everyone, but it didn't pose any major problems for me. Focusing can be a little tricky at times, but having Magic Lantern on your camera can really alleviate that difficulty. When you factor in the price of this kit and the price of its closest competitor, it's a no-brainer. At least it is for me. Looking at the comparison shots of this and Canon's 14mm counterpart, there's only a negligible difference in favor of the Canon. For a £1700 difference it's really not worth it in my humble opinion. If you need a wide angle lens, get this lens. You will not be disappointed.