Brad wrote:For a whole building?
Uh-huh!
Yes, it does face north. I have an awesome flash, but I have never tried it for that.
It does sound almost counter-intuitive, but remember, you already have quite a bit of light on your subject already, just not enough and the source is from the wrong direction. If you use the guide number alone, even with a huge honking flash at say 100', you will be blowing out the sky to pure white and overexposing the front of the building.
Here's the way I would try it. Meter on the front of the building, then stop down 1-2 stops as a starting point. Then set the flash to manual, full power. Then bracket and select the one that looks best.
That's what I would do, anyway.
