Flawed Flash
While the D100's built-in pop-up flash is great for fill flash in difficult lighting situations, working with an external high-powered flash is sometimes problematic.

Because of inconsistencies in the way the CCD reflects light, the D100's through-the-lens (TTL) flash exposure doesn't work at all with older Nikon flashes, such as my SB-24, and the camera's TTL flash stretches the definition of the term even with the built-in flash or with Nikon's newer DX-series digital strobes. In the D100 "TTL" exposure is based not on the metering of the light through the lens while an image is exposed, but on the measurement of a pre-flash that just precedes the actual shot. This works OK for group portraits, where everyone's standing still, but the pre-flash can last long enough to noticeably alter your subjects' expressions. And it won't be reliable for shooting a fast-moving dancer wearing a shiny dress, or when shooting a rapidly moving object under rapidly changing lighting: You're likely to get a bad exposure.

Furthermore, the remote TTL feature in the DX strobes (which allows film cameras to control multiple unwired strobes) is unsupported by Nikon's digital cameras. Shooting in a studio with a multiple-strobe setup, I found I had to do many test shots to find a manual exposure and color balance combination that yielded pleasing results, and I ended up with a lot of unwanted noise in high-key shots, something that was never an issue with my Nikon film cameras (see figure 6).

Figure 6: Getting good results with the D100 and studio strobes is far more difficult than with Nikon film cameras, and the resulting shots can have a lot of unwanted noise in shadows. Particularly vexing is the lack of reliable TTL flash control in this environment.

On the other hand, the D100 offers plenty of creative control over flash exposures, such as red-eye-reduction-, slow-, and rear-curtain-flash modes, as well as flash-exposure compensation (see figure 7). While the D100 doesn't do a great job of through-the-lens flash exposure, you can achieve excellent results with some manual tweaking. And being able to instantly review images and histograms on the camera's LCD goes a long way to ease the pain. As with the built-in pop-up flash, shooting with one of the DX strobes is great for fill-flash shooting, and these lights offer more power and a better angle above the lens.

Figure 7: The D100's built-in fill flash is most useful for brightening shadows in harsh lighting situations.

Figure 8: While the D100's TTL flash handling leaves room for improvement, it offers some sophisticated creative exposure options. In this hand-held shot, the camera is set to over expose the background before firing the flash to slightly underexpose the foreground.