The SB-400 has no manual exposure mode, unless controlled from my D40. The SB-400 cannot be controlled manually from any other camera as of December 2006. It works only in the excellent i-TTL mode. This means that, except on my D40, the tiny SB-400 can't be used as a battery-saving trigger for studio strobes. No problem; I can use any other old flash as a trigger in manual mode, just that I'd love to use my flyweight SB-400 if I could. Read the very nice review here