[jem]

unfortunately I don't think that the fisheye is a strong point in the Pentax lineup. It is adequate and I shot the Pentax 10-17 and the old FF 17-28 fisheye for years and I just assumed that since fisheye created a distorted image, "sharp" was not possible. Having purchased the Canon 15mm fisheye for my other system I can't believe what a good fisheye is really capable of.

I would say this is one of the ONLY instances where Pentax cannot match Canon for image quality. I don't have any experience with the other Pentax compatible 3rd party fisheye's

I really don't find this as surprising - not because your 15mm is a Canon but that it is a quality prime. As another member said - kind of an apple/oranges comparison. I have the 10-17mm Pentax as well and I like it for it's viewpoint and versatility in being an extreme zoom. For me, it picks up where my 12-24mm leaves off. For my purposes the inherent softness isn't a big problem. But, I can see how, for your chosen subject matter, the softness would be a serious flaw. And for that type of photography, I think I would be looking at a solid prime as well. My point is, they both (zoom & prime fisheye) have their place and use depending upon subject and compositional needs.

And your example: Really nice shot!

This thread has got me curious about the Sigma fisheyes - always had a weakness for the full circular effect.