This is a very highly rated lens in this price range. And it is full frame if you have a film camera that you might want to use it with. The coverage on the K10D is very close to about 90 degrees from side to side of the frame.
It does have a little barrel distortion, but is easily straightened with PTLens. Full registration is very inexpensive for this program: $15
You can download it here:
PTLens
By the way, this lens is selling for $185 to $215 everywhere else - so get it while you can!
I enjoy my Zenitar! it is a very, very sharp lens, especially stopped down a stop or so!
Here is an example after PTLens and resize:
Click on the image to view it in a larger size