It was VERY late afternoon, and we got to that location about 30 minutes after I intended to get there. (Working with my wife and her friends is a bit like herding chickens.)
As a result, the sun was already behind the hill, and I opened the aperature all the way (I believe 4.0 on that lens) in order to capture all of the light that I could capture. Of course, the result was a VERY shallow depth of field.
It was already getting so dark that I the autofocus wasn't working well, so I focused manually on Katie's face. I couldn't see well enough to notice that Abigail was out of focus!
We crossed two creeks and drove home in full dark. LOL