I am leaving for La Paz next week. I want to shoot sea lions. Wich AF-mode can you recommand for the Nikon D810? the normal AF-c, Group AF, 3-D AF. Or would you recommand to prefocus ( Fix Focus), because of he speed the sea lions move? I will be shooting the nikon 16-35mm or the Nikon 16mm FE with 1.4 teleconverter.