One of the things I love about the K135/2.5: Mount it on the Vivitar 2x TC and find yourself holding a lovely 270mm near-macro lens. Stop it down a tad. Now thar's a way to shoot flowers in the field.
-Lon
Fred wrote:
If it is SMC K 135/2.5 it is very, very good lens, very fast albeit a little heavy. It is believed as a one of the best Pentax 135mm lenses. Probably only A135/1.8 is better. Mine is like new, great built and very sharp. Highly recommended
I agree with every word that Alek has said. I'm fortunate enough to have an A* 135/1.8, but I am not willing to part with my K 135/2.5.
I would only add that, if instead it's the "Takumar Bayonet" 135/"2.5", that it is a pretty decent lens, all things considering, a little slower than the K 135/2.5, but usually a decent buy if you aren't spending too much for it (and can tolerate the silly multicolored markings on the barrel).
Fred
