I bought this lens to its extreme wide-angle focal length super 8mm and give depth and personal charm has some shots and I'm really not disappointed with the results, this objective a little extreme does not produce exaggerated distortions on its shortest focal length and sharpness is excellent between f8 and f18 aperture range that I use most often, I have not yet made full opening test but that seems unimportant to me because this type Lens is interesting for the depth of field and therefore it provides with high aperture values.
In short, this is a treat for those who want to think outside the box in their compositions and also taken to fanatics or urban views often lacking back, landscapers will also find their account they care little for the angle shots that sometimes gives surprising results in 8 mm. One regret the inability to use a polarizing or other on this beautiful pebble filter.