Left the macro lens at home today and took out my vintage 300mm f/4.5 manual focus. My biggest problems have to do with exposure, and not so much focus. The eagle is a classic example. I had lots of time to set whatever I wanted before scaring him out of the tree.
Set pinpoint metering, and turned the exposure to +1. Still get an underexposed photo. I did remember to set my camera to take RAW photos, but it's going to be awhile before I get into new software.