I was in Kannur last week for Rajesh's wedding (see 'Birthday Bash') and headed to Parassinikkadavu snake park as soon as we reached Kannur. It was almost 5.30 by then and the shadows were lengthening. Snakes and animals kept in the cages were almost impossible to shoot at that light and I quickly headed to the center of the park, which has a well where a lot of snakes (mainly rat snakes) are kept:

Even though the top portion of the well was open, the light inside was very low. Also, I needed atleast a medium telephoto to take a close shot - so I settled for the Canon EF 180mm f/3.5L (macro) lens. Even at ISO-800 I was getting a very high exposure time and had to go for an under-exposed shot. I used manual mode, f/3.5, 1/50s and ISO-800. With the camera supported by the wall around the well, I was able to take this shot.

There was another corner of the well, where the sunlight was falling through a gap. And this fellow was right there, away from the crowd, enjoying the last few minutes of sunshine. I used the same 180mm lens and clicked - this time the light was a lot better. In Av mode, f/3.5, ISO-800, with a -1 exposure compensation, the camera reported a 1/500s exposure.