The Street Photographer's Guide to Autofocus
‘Single Shot Autofocus is probably the easiest mode to get to grips with. The camera simply focuses on a subject and doesn't continue to focus, once you acquire focus. It will lock onto a subject and stay locked providing you are half-pressing the shutter button or pressing the focus button if you are using back-button focus.’
How to Zone Focus With Your Camera - A Street Photographers Guide
‘Zone Focusing is great for street photographers. Using one of three simple methods you are manually pre-focusing your camera and lens and adjusting your aperture, for a specific distance where everything will be in focus and will have a deep depth of field, within that area (zone) that you have set the focus for.’