Having recently decided a 15mm lens was in my future, I set about seeing what that future would cost me.. in order to decide how far in the future I'd need to shop. LBA forces a lot of such circular logic in order to justify more lenses, and it worked its dark magic again. Sitting on the auction site was the Sigma 15mm fisheye, gently used, for .. make offer?
I made offer. And now it's mine.
Regrets are pleasantly few. Yes I would have preferred the DA15 which is smaller and lighter, and has quick-shift focus override. On the other hand I will enjoy f/2.8 abilities and be full-frame capable if Pentax chooses to make a camera with a 36x24 sensor. Even if that's announced tomorrow I am not up for such a thing, as I really like the K-5 size and would not choose to carry a more massive camera. Still, others would definitely go for such a camera, and some of them will have DA15s - and they will covet my Sigma! And even if they don't, this is an excellent lens regardless of peers. In the 24x18-sensor world the fishiness is lessened but still there for entertaining shots. Outdoors, just keep the horizon near the center and trees away from the edge, and its fisheye characteristics are much minimized.
This should be fun!