If you’ve ever wondered how your camera will respond to extreme light conditions (or, more importantly, extreme contrast in a scene), this article is a must read:

Overexposure, Underexposure, and the Compensation Thereof (from Jeffrey Friedl’s blog)

Be sure to take the time to click through the “normalized to the base exposure” and “jpeg version normalized to the base exposure” sections. This is by far the best demonstration of a camera’s response to a high-contrast scene that I’ve seen yet.

The exact response shown here is, of course, specific to the Nikon D700 camera that Jeffrey uses, though you should expect similar behavior from other DSLRs. What will vary is how quickly the quality of the exposure will fall off as you step outside the “normal” exposure range.