It's adaptable with surgery to the aperture lever and rear element shroud.
This lens was designed with autofocus in mind so you'll find manual focus less enjoyable (no damping, short focus throw) but that's obviously not a big issue with fisheyes.
For the price I'd rather buy an old fisheye-takumar 17mm f/4 in m42 mount, or the newer 16mm pentax-a fisheye f/2.8 both of which are manual focus, more compact, and sexier altogether
