Basically: choose a wider lens, close your aperture, set your focus, and start to shoot without focusing again during the whole session. Ok, the whole technique itself is a little more complicated than that, but I think it actually sums up pretty well the idea behind it.
Zone focusing is frequently used when you do street photography, weddings, reportage, landscapes etc. The idea behind this technique is to understand that the more you close your aperture, the more things are in focus in your shot. Once you know that, you can actually set your focus once and go shoot without worrying about your focus again. And believe it or not, it’s even quicker than an autofocusing lens!
If you take a closer look at your lens, especially at its focus ring, you will find some lines and dots defining a certain area, and some numbers that correspond to your aperture – usually full stop apertures such as f/16, f/11, f/8 etc. If you set your aperture to f/16 for example, in the picture you can see that everything from 1.2 meter to infinity will be in focus. Basically, everything further away than 1.2 meter from me, will be in focus when I take a picture. Once this is set, I actually don’t have to touch at the focus ring anymore nor my aperture, I just refine my framing and set my shutter speed.
Moreover, the wider the lens, the longer this focus zone will be. The picture used for the former example is a 35mm. However, as you can see on the picture below, this focus zone at f/16 is much thiner with a 50mm (from 2.5 meters to infinity). This is also a reason why so much street photographers use a 35mm lens or even a 28mm or a 24mm. The wider the lens, the more things will be in focus in your shot. This way they can be mure more reactive to a scene as they only have to frame, set a shutter speed and take the picture.
Of course, you are not forced to use zone focusing to focus to infinity. When I do street photography, I tend to be in focus from 1.2 meter to infinity most of the time, but if I know something is going to happen right in front of me, I just slightly rotate the focus ring in order to get in focus from 0.7 meter to 1.5 meter or so. It doesn’t have to be very precise for a closer shot. It takes practice to know and feel how much you should turn that ring. But trust me, it works every time.
Combining this zone focusing technique and the Sunny 16 rule (find out more about this very important technique here), you are actually sure to get a good exposure and a shot in focus! This is why this technique is very important to know, it may be a good way to start film photography or a good way to start over with a different feel when you shoot.
Zone focusing should be used when you can actually close your aperture a little – when you’re in a bright sunlight or if you use a fast film – but it clearly doesn’t work if you have to use a wide aperture such as f/2.8 or f/1.4. It doesn’t work well also if you want to isolate your subject from your background – obviously because you have to choose a narrower aperture – but if may sometimes give you interesting results on larger format than 35mm and if the subject is very close to you.
The Sunny 16 rule and the zone focusing technique are the only two techniques I use every time I shoot. It’s the best way to be quick and creative with your framing, especially if you shoot street photography a lot. However, if I have the time to take my shots, especially for portraits, I always use a trusty light meter and I focus manually.
I might write something about street photography, tell me in the comments if it is something that might interest you in the comments!