According to Thom Hogan in his excellent "Complete Guide to the
Fuji FinePix Pro S2" the presets should approximate the following
Kelvin values:
Sunny 5400K
I'm actually beginning to think it's slightly higher than that, perhaps 5500K, maybe 5600K.
Shade 6000K - 7000K
Fluorescent 1 4100K - 4200K
Fluorescent 2 3000K
Fluorescent 3 3450K
Incandescent 3000K
Note that Thom also says that fluorescent K is notioriously
difficult to judge, because of various manufacturing standards.
Actually, it's because fluorescent light is not a heat-source type of light and doesn't emit a continuous spectrum. Thus, it's difficult to assign an exact color temperature because Kelvin involves a black-body heat source and continuous spectrum.
Also, note that Fuji's published numbers are lower than I've seen elsewhere else for fluorescent. #2 is obviously a "warm tube" of some sort, while #1 is obviously a "daylight tube" of some sort, but none of the Fuji supplied numbers I've seen come close to matching what fluorescent bulb manufactuers give in their technical specs. Perhaps Fuji's using Japanese standard bulbs I'm not aware of, perhaps they've got the numbers wrong, or perhaps they've made a visual assessment to assign the numbers (remember, the S2 tends to overemphasize reds and has more yellow in the greens than normal). I think the primary thing to take away is this: if you look at the labels on the tubes and see "warm", then #2 or #3 are the clear choices. If you see "daylight," then #1 or #3 are the likely choices. If it's an older bulb or not marked, I'd start at #3. Of course, you could simply do a custom white balance and ignore those, which is what I do.
For those of you comparing D100s and S2s, white balance is one area where the Nikon beats the Fuji hands down. While the Fuji gets Automatic white balance correct more often, it just simply doesn't have the setting flexibility for someone who knows color temps well and wants to manipulate them directly.
--
Thom Hogan
author, Nikon Field Guide
author, Nikon Flash Guide
author, Complete Guide to the Nikon D100
author, Complete Guide to the Nikon D1, D1h, & D1x
http://www.bythom.com 
