Other methods of controlling fo cus

Focus & Recompose Using the centre focus sensor, and AF-S (Single-servo AF mode), point the focus sensor at the subject, half depress and hold the shutter release button to focus and then hold the focus. Recompose the picture, then finish pressing the button to take the picture. The focus will be held as long as you hold down the button, allowing you to take multiple pictures if one of the drive modes is selected. As soon as you release the button, and press it again, then the camera will refocus.

Good for accurately focusing on a completely stationary object

Bad for any moving object. It can also lead to poor composition, and can give the game away when shooting street photography with the subject at any point within the frame. Back button focus Advocates of back button focus swear by this method, where the autofocus activation function is removed from the shutter release button and focus is initiated using the AF-On button on the back of the camera. The camera should be in AF-C mode so it will continuously refocus whilst the AF-on button is held down. To lock the focus, simply release the AF-On button.

This method works well if you’re using a Dynamic AF-Area, where the camera selects the focus point. If you want to use a moveable point focus, then this method is not ideal, as your thumb has to activate the AF-on button whilst moving the focus sensor, giving it two jobs to do at the same time. This, for me, is where back button focus falls flat. Good for sports and other actionpacked photography; focus tracking; shooting on a tripod Bad for precise and accurate focusing; combining with a moveable focus sensor