Dan Eckert

I've been doing some gaffing lately on small sets with digital cameras and I've wondered if I need an incident meter just to be on top of things when the DP asks for a change. It seems like I can get by without one as I've learned generally what I need to do to raise or lower a light's output a stop or two. But I'm green still, and I don't want to be caught off guard if a DP asks for something specific. Are there instances anyone has had on set where they were glad they had a light meter and knew how to use it?