Inside Tech Tip: Back-Button Focus

This ‘inside tip’ is one that many pro shooters use – and with good reason.  This technique is used when you wish to focus on a particular subject/object and then subsequently re-compose the image, leaving the chosen object in focus.  Back-button focusing, in essence, gives you the freedom to move between a chosen subject and composition, all the while keeping said object in focus.  Your camera won’t refocus on something that momentarily leaves and/or re-enters the scene. 

The most common method of focusing on a subject is to press the shutter button halfway to signal the camera to autofocus on the subjects. Back-button focusing, by contrast, often uses the * button or the AF-ON button (on some models it is located at the top right hand side of the camera body).  This technique is commonly used in fast-action sports and in busy situations where capturing a moment at the ready is imperative. 

This technique takes a bit of getting used to but, once you do, this technique has many advantages. It can also help you in situations where you need to focus between two subjects, all while recomposing the shot.  Like all techniques, practice is key, and with a little bit of experimentation, you may find the back-button focus technique to be one of the most useful you use.