Very nice post. I like on the one hand how you describe the light setting and on the other hand of course how the pictures turned out :)
But why did you mention the ND filter for the 2.0 1/250 photo? Wouldn't a shorter shutter speed like 1/2000 mean the same?
The correct exposure would have been f16 because it was full sun. But I wanted a shallow depth of field, so I slapped on my varying ND filter to knock down a few stops of light. It's like putting sunglasses on your lens. A great trick I learned by working on movie sets.
Lastly, when working with flash the limitation for most DSLR's is the flash sync speed. For my Nikon D800 it is 1/250 of a second.
I see! So the flash was the parameter I was missing :)
When dealing with flash there are two other variables of exposure to consider. It gets more complicated but a lot more control.