This highly rated lens, as well as the sister lenses, the SMC 28mm f3.5, SMC 35mm f3.5 are among the best wide angle lenses in their time, at least certain in the Pentax line. Even today, the optical quality of these lenses stands up to the modern counter parts. Very sharp, excellent resistance to flare, well made, small and light.

I bought this lens, along with the SMC 300mm f4 from Stuart, a very nice guy! Got a chance to use it today on my "new" 1D Mark II. From the sample pictures, I am very happy with the image quality and I can see myself using this lens a lot.