With your meter, you just have to change the mode from the one you use in studio (synch flash) to ambient, and you are set.
Also, don't point an incident meter downward unless the light that you want to expose for is coming from below. The advice to do that was for reflected meters, like the ones in cameras. But you already have a far superior tool to the in-camera meter, so I would just use it.
I have the same meter as you do. Don't have the spot meter attachment, don't see the need for my work.
Originally Posted by rince
I use the "normal" dome out, pointed at the camera method for most shots. I duplex, dome in, when back lit. You'll see what that means when you get Dunn & Wakefield's book.
I developed 8 rolls Saturday from my RB and metered that way; every frame was exposed "just fine thank you", not a single screwy exposure in the lot.
Verify the right ISO/EI is dialed into the meter then trust what it tells you.