On 30 Sep 2011 09:35:33 GMT, JakeD wrote:

Thanks to all for the suggestions. My cameras are already supposedly
weather-proof, but I am thinking that rain drops collecting on the front
lense could be an issue.

If the camera is already weatherproof put a lens hood on. Depending
upon the field of view of the lens a short length of 40mm or larger
pipe will suffice to keep the rain off. Experiment with lengths until
you start getting dark areas forming in the corners of the frame.
Paint the inside of the tube with blackboard paint and if splashing
rain is a real problem choose a larger tube and line it with thin foam
to stop splashing.

The built in IR illumination on most cheap cameras is of little use
except at very short range.