Two white rhinos

I took this photograph of two white rhinos fighting over a dusty mud hole in Namibia as the sun was touching the horizon in the west. You can see a streak of faint reddish light in the foreground. That meant that the light level was quite low, and as I look back on my settings -- 1/200, f/4, 500 ISO -- I realize I made a mistake. The shutter speed was too slow, especially given the movement of the animals and the fact that I was using a 500mm f/4 lens hand held. My camera at the time was a Canon 5D Mark II, and admittedly it couldn't handle noise as well as cameras today. Still, the ISO should should have been higher so the shutter could have been faster. Too much noise can be dealt with to a certain degree, but an unsharp picture means its worthless. The general rule with using telephotos is that the shutter speed should be the reciprocal of the focal length. In other words, my shutter should have been 1/500. Today I would have used 1/1000th of a second just to be sure the picture was tack sharp. This shot is, in fact, tack sharp, but I got lucky. The great thing about so many newer cameras now is that we can use high ISO settings without the concern of too much noise. And with Neat Image software, if there is too much noise, we can eliminate most of it.