This image (50% reduced size and taken with my Canon 6D with a 400mm lens - 7 shot HDR using Enfuse with very little additional post-processing necessary) is a pretty good representation of what you see with the naked eye. At totality the corona produces easily defined streamers that extend out several times the length the the sun \ moon combination. The corona isn't so bright that it blows out and it isn't so dim as to be hard to see. It's really an incredible thing to see. A corona like this can only be seen at totality. Since the photosphere (surface) is 100,000 times brighter than the corona the corona can only be seen in totality since even a small sliver of the exposed sun blows it all out to the naked eye. As the sun heads to totality light levels drop a bit for the last 20 minutes before it happens. About 20-30 seconds before totality the light levels completely crash to twilight- like darkness. A few dozen stars can be seen and the sun takes on a look that is unlike what it was like only a half minute earlier. Even things like solar flares on the edge of the sun can be seen with the naked eye. Some interesting observations: The dogs and animals in the area started going bonkers about 10 minutes before the totality event and kept it up until about 5 minutes after. One guy even noticed bats flying around quite excitedly. The temperature also dropped a lot. I ended up putting my jacket back on for ten minutes. 20 seconds before totality the people in the area erupted in cheers of excitement. That isn't surprising since during that period the light levels and temperature noticeably drop on a second by second basis and the sun takes on its new and amazing character.