May 18, 2012

A Look into Depth of Field for Beginner Photographers

Photography can be a fantastically rewarding hobby - and although it may have once been an expensive one, equipment is slowly but surely becoming more accessible to everyone. With this in mind, it’s easy to improve your skills without much professional training or the most expensive kit.

Take depth of field for example. This is a term that is thrown around a lot in the world of photography, but for beginners, it’s hard to catch up with the jargon. In many ways this is a very technical part of photography, but it’s not too difficult for novices to grasp. OK Let’s break it down…

What is Depth of Field (DoF) in digital photography ?

Depth of field is essentially an area of sharpness:  it encompasses the distance between the nearest points in shot, all the way to the further objects. This area gives a zone to choose focus from. Of course, it is up to the photographer, what should be in focus and how sharply they want this part to appear.

depth of field photo

Knowing the terms for everything isn’t the be-all and end-all, but certainly with photography enthusiasts it can be difficult to avoid in a conversation.

How to get the desired Depth of Field with your camera ?

The depth of field, or this specific zone, is normally influenced by three factors; the aperture, the length of your lens, and how far away you are from what you want to photograph.

Talking about aperture in optics, this is simply referring to the opening in your camera through which light (and your image) travels. It is this opening that determines just how the rays of light come into your camera in the first place and can vary between different makes and models of camera. In the same way the shutter speed is in relation to how long the light has to reach the sensor in your camera, the aperture is in regards to the amount of light.

a) How to get wide DoF

If we’re getting technical again, aperture is often referred to as an f-stop and is expressed as numbers. You may be familiar with this as a decimal number. As the f-number increases, the depth of field increases too. For example, an aperture of f/32 will be greater than that of f/5.

wide depth of field 

When most of the image is sharp, this would be a wide depth of field. This is easier to achieve with a wider focal lens, as it allows you to see more of an area. Think about taking a photograph but you want to get more into your image. What do you do? Step backwards! Well, a wide angle lens allows you to get this additional depth of field without tripping backwards and bringing your camera all the way to your chin.

b) How to get shallow DoF

On the opposite end, if you are after a very specific area, you are restricting the depth of field, and so a telephoto lens is ideal in capturing these instances, particularly if your subject you want to concentrate on is at a reasonable distance away. Unlike the wide DoF, shallow DoF is the result of lowering down the f-number on your camera.

shallow depth of field example 1

shallow depth of field example 2

In order to get the balance right, depending on what end result you are after, there are plenty of calculators out there in order to estimate depth of field, many of which can be found online.

In this sense, photography and it’s depth of field can be meticulously planned prior to even taking your equipment out of its casing. Although incredibly useful, it’s important to remember not to do this for every image.

Despite being able to carefully calculate the depth of field in order to improve the scene of a selected picture, it is sometimes good to have these skills as a backup and instead to use your eyes to judge the situation. Photography is more often than not all about being captured in the moment, and being able to take a snapshot moment, and sometime you just need to feel it.

Brett Harkness

About the Guest Author:
Brett is a professional photography training provider and a part time commercial photographer. If you’d like to brush up your skills with some photography training, Brett provides courses in Manchester, UK.