The autofocus system will automatically adjust to keep your subject in focus, and the focus point stays red because the system is continually focusing. Download Here. Covers the following cameras: Nikon D6, D5, D4, D4s. Nikon D, D, D, Nikon D, D NIkon D, D Nikon D Nikon D, D, D Nikon D5xxx series, D3xxx series. Best for both moving and still subjects in the Description. This fun and easy guide helps you understand and use all the dials and modes, manage photo size and quality, take creative cont