About the calculations, in the direct light where I was shooting the egrets I was getting a setting of 1/1600 at f/5.6 at ISO 400 from incident reading. I was shooting the egrets in direct light at 1/3200. this guy perched next to me at 45 degrees from direct sun and his face was in shadow. I was shooting manual and my existing dialed in settings rendered the image too dark, so I changed speed to 1/320 which is what I mean by the calculations...:D which got me the detail I wanted. I hope I make sense.
I've been trying to use the incident meter when shooting white birds especially in a setting like Gatorland and getting a base manual setting and adjusting depending on subject. I ended up nailing most of the exposure situations over there with the egrets.