The snake was completely unconcerned with me. I mean completely unphased. It could well have been blind because it didn't react at all to me moving around it. I was able to get fairly close and waved my hand about a foot from it's head in an attempt to get some sort of reaction, but I got nothing.
This photo was taken with my 300mm zoom (focal length of 160mm) so I would have been at least 3 feet away. Several attempts to get a shot because it was moving it's head this way and that, would stop for a second in which I could focus, and then move again as I took the shot (resulting in blurred image or soft focus).