One of the most challenging things i have experienced during my safari and using a fixed lens (600mm eqv) is putting moving subject in a full frame, without cutting any parts of the subject. This male leopard was descending the tree at the end of the day and made his way to the bushes. My focus was to keep this big cat entirely in the frame while looking through the viewfinder, any movement could ruin the picture. There is no other choice, you move back its gone, its only a matter of seconds.