I've tried that with no result. I dismantled the camera to see if there was any indication of damp, and it does look like there might have been. How that would have happened is a puzzle as they are water tight. It may just be down to the age of the camera. As the camera is detecting and recording motion, I have fitted an LED floodlight with PIR to cover the same area as the camera with the result that any motion will be recorded in colour.