Give this a go stew
http://www.sharpcap.co.uk/ , i have found it the best software to date that's free for webcam imaging. Has all the gain/shutter/lighting controls on offer and have used it with c210 Logitech and the 900nc
Have fiddle in the lounge room and tinker with the cam just hooked up to the pc and looking at a wall
Cloudy nights don't have to be a loss lol.