Overall, I liked how this photo came out, however the redish halo around the sun illustrates a drawback of digital photography to which film is not susceptible. The sun is so bright that the pixels it covers in the CCD (charge-coupled device) array of the camera become saturated. The saturated detector pixels continue to exhibit Einstein's photoelectric effect (see his famous 1905 paper, written at the age of 26!), producing electrons as they absorb photons, but they can only store a finite number of electrons (finite capacitance); when the "bucket" gets full, the excess electrons wander out into nearby unsaturated pixels, producing the halo. This phenomenon is often called blooming, and good CCD's implement tricky ways to sluff off this excess charge, so that blooming is minimized. I would think Nikon has implemented these tricks, as this is intended as a high-end imaging sensor, so perhaps the results here are actually far better than they would be without efforts to correct the problem. Of course, perhaps I have just misdiagnosed the problem entirely, but from the reading I've done, this seems the most likely reason for that halo. I did apply some sharpening to this photo, which can produce lines at boundaries between areas with a big difference in brightness, but not that much, and the halo was present in the RAW camera image, before any processing at all. If you agree with my analysis, or have a better idea what is causing the halo, add a comment by clicking on the comments field below the picture.