Here's what I would suggest, see if this helps: I'm assuming you don't have a gray card. The skin on the palm of your hand will do as a handy substitute. Put the palm of your hand in the same light your subject is in, in such a way that it fills the viewfinder of your camera. Take the exposure recommendation of your meter, and double the exposure (either open up 1 stop, or expose for twice as long). I've heard that this will work even if you have a dark skin tone otherwise, as the amount of light reflected off of the palm of a human hand is relatively constant regardless of race. Then bracket. Take notes and you'll see where the negative or scan ends up looking good.