Last glimpse of the Sun's photosphere

This was one of a sequence of shots of the setting Sun last Wednesday night from Kitt Peak. You can just see the last bit of the suns bright surface as it dips below the distant hills. In fact, the edge of the sun is broken into several bead-like parts. I did get about 2 more images before the sun was entirely gone, but this one had the bead affect best. This image was taken at 300mm focal length with an exposure of 1/640 seconds at f/8, ISO 400.