Special? So special? You're in an
elite group of people, my friend, who own the fastest lens Pentax ever made
.
It's a bloody great lens if you can find it. Since you have, enjoy it, either by taking photos through it or putting it in a sock and beating your enemies with it, because, man, is it one
solid hunk of glass. Feels like it means business.
It's seven elements, six groups (that's one louder than the f1.4, innit,) either eight or night aperture blades depending if it's a K or an A model, respectively. You can tell simply by looking at the label on the front of the lens - inside the filter ring, it's a K, outside, an A. Also, this is where the phrase "SMC PENTAX-A" will be written - there'll be no letter after the "PENTAX" on any K lens.
For such a fast lens, what little there is in focus is sharp, and when stopped down it's amazing. It was a real pro-aimed lens, back in the day, and there're times when I wish Pentax made the f1.2 into an autofocus lens like they did with the f1.4.