Short answer: The hyperfocal distance is the shortest camera to subject distance where the depth of field is infinity.
Short Video Introduction
Check out this video from Matt Granger for a great quick introduction to hyperfocal distance:
Maximising Depth of Field
Hyperfocal distance is about maximising your depth of field. It’s about maximising the area that is acceptably sharp in the image we are capturing. When you set focus to the hyperfocal distance the depth of field starts half way from the camera to the hyperfocal distance and continues to infinity.
For a deep dive into depth of field check out this post.
Hyperfocal Distance Tables
PhotoPills have a great online tool for finding the hyperfocal distance for a wide range of cameras.
Below is a section from a hyperfocal distance table for the Sony A6000:
|Focal Length (mm)||f/5.6||f/8||f/11|
From this we can see that if the aperture is set to f/8 and the focal length is 28mm then our hyperfocal distance is 4.93m. This means as long as our subject is at least half way towards this distance, e.g. 2.47 metres away or further, then they will be within the depth of field and ‘acceptably sharp’.
Why is This Useful?
Having a very large depth of field, from near in front of the camera to infinity, is particularly useful for landscape photography. In the below image the dry stone wall in the foreground is in focus and so are the distant hills.
When setting focus manually, for instance on an older camera, then setting focus at the hyperfocal distance means you can shoot freely. As long as your subject is beyond half way to the hyperfocal distance then it should be acceptably sharp, as well as everything in the background.
Hyperfocal distance is also useful because when we know this distance we know that if our subject is further away than the hyperfocal distance and we focus on them, then everything behind them will be acceptably sharp because the depth of field will be infinity.