Took these test shots with a lens that I've been looking for quite some time, the Pentax A 200mm f/4.
A nice manual focus lens that's a little hard to find as it didn't really have a long production run.
Nice build quality, good manual focus feel, not too heavy at about 400g and it has 8 aperture blades.
This lens has the A setting on the aperture ring so it can use every exposure mode available, something I can't do without.

The wild dog (actually very friendly) and monkeys were shot at a reservoir.
All with the K-7 wide open at f/4, uncropped and straight from the camera (Exif is intact).
Sharpness of this lens is good and there can be a little CA in high contrast situations but I just love the color rendition of original Pentax lenses...

[Adam]

Nice photos...but, more importantly, this thread made me aware of the existence of that particular lens, as I had completely forgotten about it. I've got an A200/4 macro, but not the regular version. I'm off to satisfy my LBA...