Logitech Quickcam Pro 3000 Long Exposure Modification
Before I describe how I modified my webcam I must give credit to two people, without whom this project would have been utterly impossible.
Steve Chambers made the original discovery that many webcams can be modified for long exposures. He figured out how to do it to a some webcams (Philips Vesta models and Philips ToUcam models), and generously put the details of the mod on his website. Hundreds of people around the world have been able to modify their own webcams following Steve's instructions as a result. However, the Quickcam Pro 3000 uses different chips than the Philips webcams and Steve's mod cannot be applied point for point to the Quickcam Pro 3000. (Please note that Steve holds a copyright on his webcam modification technique. Here is a direct link to the copyright terms.
Martin Burri, following Steve's lead, figured out exactly how to adapt Steve's mod to the Quickcam Pro 3000, and just like Steve, he displayed his mod in detail for the whole world to see as well. My mod is basically a duplicate of Martin's mod, but I made a number of changes along the way. Some changes were the result of a different high-level design I had in mind, some changes were the result details I thought I could improve on, and some changes were forced on me along the way as I effectively ruined the camera bit by bit and had to work around my errors in order to keep making forward progress. In the end I was totally successful and I now have a fabulous long exposure webcam.
Disclaimer: I accept no responsibility for anything that results from anyone attempting to modify a webcam using my description. This is some really hard electronics work due to the incredibly miniscule scale of the electronics involved. You have been warned. Now go bust open your webcam!