What happened to the ambient light sensor?
It isn’t needed anymore (and didn’t work that great in the first place). Basically, the only time it was used was when you pressed the FUNC button while doing a PRE white balance measurement. That not only complicated the white balance function, but in practice it didn’t always do as good a job as using the sensor. Why no ISO 100? The D3 (and D300) have a new low setting, which is essentially ISO 100. Nikon has been very consistent in following proposed ISO guidelines for ISO: the base ISO should be the optimal light gathering point for the sensor, and in both sensor’s cases, that would be ISO 200. Normally with a lower-than-optimal ISO setting the camera tries to keep the midtone curve the same and the highlights tend to clip faster, essentially reducing usable dynamic range. And for what it’s worth, there are intermediate settings at 1/3 stops between 100 and 200, as well (L0.3, L0.7, and L1; you’re going to have to think backwards to understand this, though!). But expect ISO 100 to
