Understanding depth of field (DOF) and how to use it is one of the most important learning stages in creative photography. If we always keep our cameras on full auto mode, so that the (DOF) is chosen for us, we will never have full creative control over our images.
And although it sounds complicated at first, it’s actually very easy to understand!
The term depth of field refers to the amount of a photograph that appears sharp from front to back. So a photograph with a large (DOF) will be sharp from foreground to background, while one with a shallow depth of field will have a limited zone of sharpness, with areas in front of or behind that out of focus.
The depth of field is controlled by your choice of aperture, which is also known as an f-stop. This is a slightly bizarre sounding range of numbers, and depending on the lens it will usually start at around f2.8, and end at around f32. The formula is simple – the smaller the f-stop number, the shallower the (DOF) .
If you use your camera’s aperture priority (or AV) mode, you will be able to choose your f-stop, and the camera will set the appropriate shutter speed so that you will have a correct 'creative' exposure. And now you have control over the (DOF)!
In this blog I wanted to look particularly at using shallow depth of field. Why might you choose to have part of your photograph out of focus?
The reason is very often to do with the background to your subject. Imagine a person standing in front of a cluttered backdrop - a portrait of this person will look much better if the background is thrown right out of focus, than if it is sharp.
In the portrait above, DOP has been used, so you focus on the face and primarily the eyes. By the time you get to the ears, you can see the focus is already much softer.
A sharply focused, cluttered background will distract the viewer’s eye from the subject of the photograph, while a soft wash of out of focus colour in the background will allow the eye to rest on the subject.
This is true in many different genres of creative photography as well as portraiture – wildlife photography, flower photography, street photography, and many others may all benefit in the same way from having distracting or irrelevant detail thrown out of focus.
If you haven’t tried it before, set your camera on aperture priority, choose a low f-stop number, and have a go – you may find a whole new way of seeing photographs!