Part 7 Lesson 3: Settings for landscape photography

depth of field

Cast your mind back to the beginning of the course, when we looked at how aperture affects depth of field - large aperture = small depth of field, and small aperture = large depth of field.

With landscape photography you usually want a larger depth of field, so that the landscape appears sharp from just in front of you all the way to the horizon. To achieve this, the key things to remember are:

1. A small aperture gives a large depth of field, so use f16 or f22.

2. Image quality decreases at extreme apertures, so avoid your smallest (each lens has a "sweet spot" around f8 that will produce the sharpest images so aim to stay as close to that as you can).

3. Depth of field is the section of your image that appears acceptably sharp to the naked eye, running in a line away from the camera towards the horizon.

4. Depth of field starts from your focus point and extends in front of and behind:

Hyperfocal distance

When you are standing in front of an epic landscape, what do you focus on? Are you on auto focus or manual focus?

Chances are, if you don't override the camera, you will focus on the horizon by default:

Your depth of field will start at the horizon, where you focussed, and extend in front of and behind that point.Think for a moment about what will show up on the final image though. Do you actually need all that area behind the mountain to be sharply focussed? No - because you can't see it. This area is wasted depth of field:

Now do some more mental gymnastics and think what would happen if you moved the focus point towards the photographer.

As you move the focus point, the depth of field moves with it. (You have to be using manual focus for this, you can't really rely on auto focus unless you are adept with the focus-recompose method.)

So you can use this technique of not focussing on your subject, but instead focussing in front of it, to extend the depth of field greatly. Here, the depth of field starts just in front of the photographer and still reaches all the way to the horizon:

The closest focussing point at which the depth of field will still extend all the way to the horizon (or "infinity" as your camera manual will call it) is called the hyperfocal distance for that particular lens. The exact distance will change according to:

1. the focal length of your lens (the "mm" number)

2. the aperture you are using

3. the crop factor of your camera

Do you like the detail or do you prefer a broad brush approach?

If you are a broad brush kind of photographer, all you really need to remember is that if you focus approximately 1/3 of the way into the scene, at f8 or f11, you will probably hit the hyperfocal distance. If it's an important shot, take a couple of extras, moving the focus point a bit further away from you each time.

If you want to know the exact hyperfocal distance, down to the nearest centimetre, then you will love hyperfocal distance tables. You can get them free online, or buy an app and carry them round with you always. I use a couple of different ones, but this is the kind of detail you get (this is from PhotoPills):

THIS WEEK'S PROJECT: Hyperfocal distance in practice

You are going to take 4 images with a different depth of field in each, and then compare them carefully to see if you notice a difference.

1. Use the same lens for all 4 shots.

2. Pick a scene with a clear field of view from your feet to the horizon. A big field with a tree at the end of it will do, or a view down a street. You can also do this exercise at table-top scale, but use larger apertures to see the effect more clearly (eg. f8 and f4).

3. Pick 2 apertures. One should be your smallest (eg. f22 or f16), and the other should be a mid-range (eg. f8 or f5.6). Write down the hyperfocal distances for your lens at each aperture. PhotoPills has a free calculator.

4. Take these 4 photos:

- focus on the horizon at f22

- focus on the hyperfocal distance point at f22

- focus on the horizon at f8

- focus on the hyperfocal distance point at f8

5. Download all images and compare at 100% magnification. Can you tell the difference between them?