Fisheye HDR

I photographed this incredible 12-story spiral staircase in Ljubljana, Slovenia.  I used a 15mm Canon fisheye, and what's unique about shooting round subjects with a fisheye is that there is no apparent distortion because you can't make something that is round seem 'more' round.  Because this is such an extreme wide angle, there appears to be very little movement in the viewfinder when hand holding the lens.  Therefore, I was able to use the HDR technique in this situation without a tripod (which would have been impossible, anyway, to shoot straight downward) to hold as much detail as possible in the tones.  I used two-f/stop increments for the three frames I shot, and I had to raise the ISO to 1600 because it was quite dark.  I chose an aperture of f/5.6 instead of the maximum f/2.8 because I wanted to hold depth of field on the immediate foreground.