Setting a custom white balance to correct the colour-cast from halogen lamps can work wonders for cold, pre-dawn light.
Black-crowned Night Heron in pre-dawn light.
Canon EOS 1DX, EF70-200mm f/2.8L IS II, 1/800 sec @ f/4, ISO 2000, 2 x 1000W halogen floodlights tripod, hide
In the semi-darkness of pre-dawn, this Night Heron was illuminated by halogen floodlights. Halogen light gives a warm orange colour-cast to an image if you let the camera manage white balance. To remove the cast, the white balance on the camera is set to a low value (2800k). This has the effect of strengthening the blues in the cold natural ambient light. A high shutter speed was used to freeze the Heron and capture the rounded splashes of rain water on the surface of the lake.