The art of practical photography has been around for 176 years. Coined by Sir John Herschel in 1839, the word “photography” simply means “drawing with light”.

With that in mind, I wanted to write a three part series all about light, and how to use it to record incredible moments in the bush. The exposure triangle, and all the theories that go with it, can be incredibly daunting for new photographers. As I mentioned in my last blog, whether you are a seasoned professional or brand new to photography, these are fundamental principles that we all need to know and understand to get the best out of our photography. As with anything that requires skill and knowledge, photography is about virtuosity- being able to do the common uncommonly well.

Without giving your brain a workout, and going into too much detail, the DSLR cameras today work by using an array of millions of tiny cavities called “photosites” to collect the information that is coming thought the lens. In a nutshell, this information is a record of the light that the lens has captured- the shades and tones, the brightness and darkness, and the different colours. That’s all the technical stuff out the way.

As photographers, we practice the art of capturing moments (the moments that we draw with light). When taking photographs in the field, we want to ensure that what we are recording is what we saw through our own eyes- thus accurately representing the moment that stirred us to take the photograph in the first place. In order to properly represent these moments, you need to understand the way that your camera records the light around you so that you can use it to your full advantage. The first, and possibly most important, thing to understand is aperture.

Aperture – Amount of light. 

Before I go any further, I want you to link two words together forever in your mind: Aperture and pupil. An aperture is a hole or opening through which light travels- just like the pupil of your eye. The aperture opens and closes to increase or decrease the amount of light that your camera records.  Again, think of your pupil dilating and constricting when you shine a torch into your eye.

F/stops and aperture

Again, without making your brain sweat unnecessarily, aperture is linked to a measurement called F-stops, which is a calculation based on the focal length and the diameter of the aperture at any one time. Simply put, f-stops (or more commonly recognized as f/n) are a way to understand how much light you are letting in at any one time in order to control it.

Here’s the important thing to remember about f-stop numbers (and something that has always been slightly counter-intuitive to me): The smaller the f/n number, the more light is being let in, and the larger the ‘pupil’ of the lens. The larger the f/n number, the less light and the smaller the ‘pupil’ of the lens.

Depth of field and aperture

OK, so you know that the aperture is the opening, or pupil, through which the light travels to the sensor. The amount of light is measured in f/stop numbers, and that a small f/stop represents a wide opening and a large f/stop represents a very small opening. The next relationship you need to know about is that of aperture and depth of field. Depth of field (or DOP for short) is the distance between the nearest and the furthest objects that appears acceptably sharp in an image. A shallow DOP will give that beautiful macro feel to a photograph, where there is a small amount of the image in focus and the rest is softly blurred in the background. A deep DOP will render an image where almost everything is in focus- typically a landscape or wide-angle shot. Manipulating the aperture is the easiest and most often utilized way to adjust DOP.

The most important thing you’ll need to remember is that a wide aperture (small f/stop number) will create the shallowest DOP as it lets in a large amount of light. On the other end of the spectrum, a large f/stop number will let in a much smaller amount of light, creating a deep DOP, allowing much more of the photograph to be in focus. This is typical of landscape photography, or wide-angle shots.

This shot of our recent Easter Breakfast demonstrates a shallow depth of field. It was shot on f/5.6 on a bright morning, so not my lowest f/stop number, yet it still let in enough light to give that shallow feel, and the soft blurry background with just the front section in focus. Photograph by Amanda Ritchie

This shot shows you what a deep DOP looks like, with a large amount of the photograph in focus. This was shot by Richard Laburn on f/22.

The effect of aperture on other parameters of light

The last thing I want to include in this post is that everything to do with the way we manipulate the light available to us is dependent on each other. If you go out and practice using your aperture priority setting on your camera to see how the various f/stops change the feel of your image, you will also need to keep in mind that shutter speed, and sometimes ISO, will be affected. But more on that in later posts.

For now, go and take a look at our most recent post on The Week in Pictures and notice the f/stop numbers that are referenced in each caption. You will see that the theory that I have touched on above has been put into practice. For even more information on this, and other aspects of wildlife photography, download our eBook here.

As always, practice makes perfect, so grab every opportunity that you have to play around with aperture, and learn from the various ways you can use the amount of light available to you to capture life around you.

Let me know in the comments below if you found this post useful, and if you have any other ideas you would like me to explore in future blog posts.