Most of us completely rely on the autofocus of our camera. On my Nikon D800 there are two options: AF-S and AF-C. The first one is used for still life objects and the latter for moving objects. The S stands for Single Servo and the C for Continuous Servo. If you know in advance which situation applies it is easy to set the relevant option.
However, in practice when I shoot a group activity, I like to combine sport photography of activities and journalistic portrait photography of individuals. I have to act fast, so, there is no way I will continuously change from AF-S to AF-C and back again. For me this is not going to work.
After reading the extensive guides of the Nikon D800 by Thom Hogan (he writes excellent guides) I found out about the Pro Approach to Autofocus. The idea is to separate focus and release.
Standard they are combined in the Shutter Release. Pressing it halfway is to focus and pressing it completely is releasing the shutter. In the Pro Approach the focus is assigned to the AF-ON button. The only function of Shutter Release button is release. Furthermore, set the focus mode to AF-C.
This enables us to do the following:
- Portrait Focus on, for example, the eye by pressing the AF-ON button, then let go the button. Reframe and then press the Shutter Release.
- Sports Press and hold the AF-ON on the subject to focus on. While holding the AF-ON press the Shutter Release. In this case the AF-C mode makes sure the subject is followed even though it moves through the screen.
In the beginning it takes some time to get use to. Now it has become second nature. The only disadvantage is that it is not easy to give the camera to somebody else to take a picture. However, for me it makes life a lot easier.