A guide to depth of field, hyperfocal distance and focusing techniques
Pictures that are sharp from the foreground through to infinity, pinhole camera pictures that are slightly out of focus, pictures that display the “Orton” effect. Do landscape pictures need to have front-to-back sharpness any more? Mark Bauer explains all about DOF, diffraction and hyperfocal distance
Although it is not a ‘rule’ of landscape photography that pictures should be sharp from the foreground through to infinity, certainly it is a strong tendency, and I go so far as to say that the vast majority of landscape images exhibit this front-to-back sharpness.
In order to achieve this look, it is important to understand depth of field, and how to control it. The first thing we need to understand is that there is only one point in a photograph that actually is truly in focus. Depth of field is the zone, in front of and behind the actual point of focus, which appears sharp.
The main factors which affect depth of field are the following:
- Lens choice: shorter focal lengths have greater depth of field than longer lenses. Wide angles are popular in landscape photography, therefore, not just for their ability to capture sweeping vistas, but also because of their greater depth of field.
- Aperture: the smaller the aperture (larger f/ number) the greater the zone of sharpness. As a result, many landscape photographs are taken with the lens set to relatively small apertures such as f/11 and f/16 (depending on camera and sensor/film size). A lot of photographers prefer to avoid stopping their lenses right down to the minimum aperture though, because the effects of diffraction (see below) can cause a softening of the image which cancels out what you gain from the increased depth of field.
- Where in the scene you focus: choosing the correct point of focus is vital. You can shoot with an ultra-wide lens stopped right down, but if you…