Many have asked how the 300 PF is for a birds in flight lens. Shooting down in FL, I had the Df / 300 PF on a shoulder strap and pulled it up “quickdraw” fashion when wanting to photograph a bird on the wing. The 300PF did an amazing job of the job! It’s so light on the shoulder, it’s great! And fast focusing and sharp images … oh ya! So in answer to the question if the 300PF is great for flying birds … it sure is!