There is nothing quite like sitting on a rock behind your camera and having hundreds of Puffins swirling around directly in front of you; it's hard to explain how much fun it is to photograph them coming directly towards you. This happens a couple of times each day during my Deluxe Atlantic Puffins Galore (and so much more) workshop.
This is the first image I made with the (then) brand new Sony 600mm f/4 GM OSS Lens and I threw the Sony FE 2X on to test the combo for fast-moving flight photography. I think it passed the test with flying colors - smile.