First, I'll briefly mention that bracketed shots are a set of generally three photos of the same scene. One is under-exposed (a rather dark shot); one is over-exposed (very bright); and one is a more typical exposure. This can be done manually by changing the shutter time for each of the three shots, but it's significantly easier to have your camera do the heavy lifting. Canon (and probably Nikon as well) has a feature on their DSLRs called auto-exposure bracketing (AEB). With AEB, the camera will automatically adjust the exposure on three successive pictures. Just turn on AEB with your desired +/- exposure values, click the shutter button three times and you're done.
While at Riverside, I took three photos of the same scene of trees using AEB. I generally use -2/0/+2, though this time I happened to use -1.66/0/+1.66. I didn't have a tripod with me, but I was able to keep fairly stable.
|Underexposed 1.66 f/stops|
|Normal (+0 f/stop) exposure|
|Overexposed 1.66 f/stops|
Individually, all these shots are pretty poor. However, they each have some valuable color data to contribute, so I combined them all together into a high dynamic range (HDR) image using Photomatix Pro. Photomatix does a great job of making HDR processing seamless. Starting with aligning images properly (since I didn't have a tripod, each of the three individual shots was slightly misaligned from the other two) and allowing me to easily tweak settings for how to do tone mapping or exposure fusion.
I've played with settings so little that I hardly know what I'm doing, yet it's interesting to see the results that Photomatix and other HDR software can produce, such as this fairly realistic blend of the three exposures: