Getting the Eagle Eye

My husband Don won a new lens this winter and I finally got out today to give it a try.  We have a pair of eagles nesting nearby.  They fly around and around the nest whenever anyone walks into the field near their nest.  I didn't have good luck getting a shot of them flying but as I was leaving one of the eagles went back to sit on the nest.  From a distance I could see the white head in the nest but didn't think I would get a decent shot.  I was amazed at how I can see the eagle keeping a close eye on me! 
The lens is a Tamron 150-600 mm.  I think we are going to have a lot of fun with this!