Great lens, but wish the images were a little more sharp.
Heath A. Wright, Amazon
11 August 2013
Summary: This is a fantastic lens, however as others have stated photos are not as sharp as they shod be at lower f-stops. At f2.8, unless you are focused to infinity, the in-focus image is not tack sharp even with a tripod.
Summary: A great wide lens, it is unique if you are looking at a prime with AF. And this was a deal breaker for me. What does this review add to the other 8 reviews: - how does the lens keep its value over time (has not been mentioned in any of the previous reviews) - list of available alternatives - no one...
Very good ultra-wide angle lens, at least when stopped down
Joseph L. Kashi, Amazon
15 December 2011
Summary: As expected, this Pentax Limited lens is extremely well-constructed and works very smoothly. It's a pleasure to use it. Optically, the edges are rather soft until stopped down to f8, at which point it's quite sharp. Contrast is excellent at all apertures and definitely enhances image quality.
Summary: I really enjoy using this lens for landscape photography. It's not super sharp wide open, but stepped down a bit becomes very nice. Good solid build quality. I find myself using this lens more and more.