I was thinking about this today and I have come to the conclusion that I prefer sunset over sunrise. I know that in many situations it will depend on the exposure of your subject; however, if I'm going to go out shooting and don't know what I will be shooting I much prefer sunset.
Is it me or does the good light last longer at sunset than at sunrise? In addition there is more light to see with to compose your photo before the shot, it's warmer, and you don't need to wake up at 3:00am.
Sunrise



