Here's my first few photos taken with the 100-400mm lens.
Here's a red-headed woodpecker (Melanerpes erythrocephalus),
then an eagle and a ringneck duck. The far away focus needs some work.
Here's some of the birds that came to the feeder in my back yard in Cincinnati, OH. I did not have my zoom lens yet so these are taken with the 12-40mm lens and cropped.