Updated: Oct 6, 2021
Take a look at the headshot below and you'll notice that the background is blurred.
This isn't because I have trouble focussing a camera: it's an entirely intentional effect known in the photography world as bokeh, and it's common practice in portrait photography. It helps to separate the subject from the background, while retaining some of the colour, character and general feel of the background. Take a look at the shots below and notice the difference that a blurred background makes.
Taken on a smartphone with the first willing model I could find, the shot on the left is a passable portrait, where the subject is in focus and the background is blurred enough that the subject stands out. In the shot on the right the background is not blurred and so it competes for the viewer's attention. It's a distraction. This is not a good portrait.
How do we achieve this effect?
This simple but effective technique may have been at your fingertips for a while without you knowing it. So here's how to add bokeh to your shots.
If you're using a smartphone, most of the models from recent years should have a dedicated portrait mode. On my Samsung Galaxy S7 it's called "selective focus" so look around in your settings and find your equivalent. In this mode you'll choose what to focus on and the camera will blur the background for you. It may even offer the chance to blur the foreground and put the focus on the background should you prefer.
If you're using a DSLR/mirrorless camera, shoot in AV (aperture priority) mode and choose a large aperture (anywhere from f/1.8 to f4 should give good results. If you don't have a lens in this aperture range invest in a 50mm f/1.8 lens. These usually come in at less than £100 and will quickly become your favourite lens.
Camera should be close to the subject, but the subject should be as far as you can get it/them from the background. The greater the disparity in these two distances, the more blur you'll get.
So that's bokeh. Give it a go and feel free to let me know how you got on!