Zone Focusing
This is one of the handiest things I ever learned.
I use it everyday with my Leica but I also used it a lot with my Pro auto focus cameras when using my 24 and 25mm lenses which have depth of field scales.
Most lenses these days are autofocus and they don’t bother with depth of field scales on their lenses anymore since so few people care to focus manually. Some thankfully do. You don’t need the scale for manually focusing directly of course.
Where it is so useful is when you want to set the focus BEFORE you bring the camera to your eye. When you prefocus on a given area (zone), whatever falls in that distance is more or less in focus.
There is only ever one point (distance) that is ever critically sharp but if it falls within the preset zone it is usually considered acceptably sharp for most purposes.
If absolute sharpness is your goal then zone focusing may not be for you. It worked for an awful lot of historic photos by legendary photographers but then nothing is for everyone and you may not even like the photos I’m thinking about. If that’s the case of course then you probably haven’t read to this point.
Now let's cut to the how to.
First choose an aperture. It doesn’t really work for wide open apertures as there is too little depth of field to work with. I typically choose f8. You can go even smaller if you want more. It is surprising how much more you get per stop.
Next, notice the scale that doesn’t move at the base of the lens. It will have a center point, likely represented as an arrow (but may just be a line). That is the actual focus point. The point of critical focus. It doesn't really matter that much for this but it’s good to know what things are in my opinion.
I’ll use a 35mm lens as a reference since it is my go to focal length for street photography. The principle applies to all focal length lenses with a depth of field scale just with different distances aligned to the f stops.
Now, with the lens at f8 consider what you are about to photograph.
Say you're walking along a busy street and you intend to photograph things/people on your side of the street. If you align the 15(feet) with the line coming from the 8 on the right side of the lens*, then the 8 on the left* side will be just to the right of the 5(feet) mark. That means that now your camera is set to photograph (in focus) anything that is between approximately 5.5 feet to 15 feet away. That is a lot of area and a very useful range for the situation.
All you have to do now is bring the camera to your eye and shoot.
This is the only way to shoot from the hip and get anything in focus routinely.
Another term that you may hear, hyper focal distance, is the same principle with one difference. It is the point where everything from a certain point to infinity is focused. I use that a lot. Most of the time in fact. I have the camera set at the hyper focal distance for my 35mm at f8 and I have it in hand and ready to go.
If I see something I am ready to photograph it. If I can get more time to do more photos then I will likely start to specifically focus on the subject. Having the camera ready to capture anything immediately without much thought or prep helps immensely since more often than not, my subjects are in motion and the moment only lasts a second or two.
When you get comfortable with zone focusing, you will be ready to release the shutter and walk on faster than any autofocus would allow.
Auto focus is great for a lot of things. I don’t think it has an advantage in street photography though and in some instances I feel it’s a liability. I hope this helped. If you have any questions feel free to ask.
*not all lenses focus by turning in the same direction. If yours is different then the principle is the exact same but you’ll align near and far on the opposite side of the scale.
