I use multiple exposures to create high dynamic range (HDR) images quite frequently. When photographing scenes with challenging exposures, this allows me to retain some details in both the highlights and shadows.
Many years ago, I captured a photograph of the Chapel of the Transfiguration in Grand Teton National Park using Kodachrome slide film. Slide film does not offer a great deal of dynamic range, so I had to choose an exposure that would retain details in the highlights (the mountains and sky) or the shadows (the interior of the church). I chose the highlights, so the interior of the chapel went dark.
I recently revisited this scene with my digital camera. This time, I captured five photographs. For the first image, I selected an exposure that would underexpose the mountains and sky slightly. This exposure so happened to be 3 stops below (-3 EV) what the matrix metering of the camera was recommending. From there, I captured four more exposures with each exposure being two stops more exposure than the previous picture. By the time I reached the fifth image, there was plenty of detail in the shadows to work with. My camera is securely mounted to a tripod throughout this process.
I then blend the five exposures using Nik's HDR Efex Pro2 software. Once I have a single blended image, I run the photo through my normal post processing steps in Lightroom 4 and Photoshop CS5. Here is the finished image:
Many times, I'll create a HDR image even though it isn't absolutely necessary given the exposure range. I find that the image quality can be higher with HDR in some cases. Rather than make significant post processing adjustments to raise the shadows and darken the highlights (which introduces noise and other artifacts), the HDR image retains full detail in those areas without the need to stretch the pixels.
An example of this was a recent photograph I captured of the Notre Dame hockey arena. After adjustments in Lightroom, the single exposure was able to retain details in the highlights and shadows. But, the HDR image retained far higher image quality throughout the photograph--particularly in the dark ceiling.
Although the dynamic range of the sensor in the Nikon D800 is amazing, I still find myself using HDR techniques under more challenging lighting conditions.