If you have a point-and-click digital camera made by Canon, you may be able to turn on all sorts of features usually reserved for more expensive SLRs. That includes live histograms, depth-of-field calculation, under and overexposure highlighting, and — best of all — shooting your pictures in RAW. The secret is CHDK, an enhanced, free software replacement firmware.

It is not clear what CHDK developer Andre Gratchev intends the initials CHDK to stand for, but the user community has speculated that it means Canon Hacker’s Development Kit. In any event, you don’t have to be a hacker to use CHDK; it is as close to a plug-and-play camera enhancement as you will find.

CHDK works because many of Canon’s recent digital cameras are based on the same DIGIC II chip. To see if your camera is supported, review the list in the CHDK FAQ. If you have a supported model, the FAQ provides step-by-step instructions for getting the correct firmware and loading it onto the camera. Although all of the supported cameras use the DIGIC II processor, each model is different, which required the CHDK developers to dump the factory firmware and do some reverse-engineering.

Let’s walk through the steps required to get CHDK rolling on the PowerShot S2 IS. And don’t worry — unlike replacement firmware customization on Wi-Fi routers and some other hardware devices, this is all non-destructive and highly unlikely to damage your camera. Nevertheless, if you are under warranty or are prone to accidents, proceed at your own risk.