Using back button focus for portrait photography offers several benefits:

Easily Switch Between Focus Modes

With back button focus, you can seamlessly switch between single-shot autofocus for static portraits and continuous autofocus for portraits with subtle movements, simply by holding or releasing the dedicated focus button. This flexibility allows you to quickly adapt to your subject’s pose and movements.

Maintain Focus Lock While Recomposing

When using single-shot autofocus, you can lock focus on your subject’s eye, then recompose the framing without having to refocus, ensuring tack-sharp portraits.This is especially useful for off-centre compositions or when working with a shallow depth of field.

Avoid Accidental Refocusing

Since the shutter release is decoupled from the focusing mechanism, you won’t accidentally refocus when taking the shot, even if something crosses in front of the camera.This prevents unintentional focus shifts that can ruin a portrait.

Precise Focus Control

With your thumb on the dedicated focus button, you have precise control over when and how long the camera acquires focus. This level of control is invaluable for portraits, allowing you to confidently focus on the most important part of your subject.

Reduce Shutter Lag

By separating focus and shutter release, back button focus can help reduce shutter lag, ensuring you capture fleeting expressions and poses. While back button focus requires some practice to master, many portrait photographers find the added control and flexibility to be invaluable for consistently nailing focus on their subjects.