The Creative Use of Aperture
Aperture controls how much of the scene appears to be in sharp focus. That’s the official version. But there’s a secret good photographers know about aperture, and it’s so simple you’ll want to rush out and try it right away. The secret is that aperture does two things very well: it can powerfully direct your viewer’s gaze and it has a huge impact on creating mood in your images. When you think about aperture this way, you begin to approach a potential photograph from a creative viewpoint first as opposed to a technical one. This is liberating because it frees you up to focus on the reason you do photography (to create your own unique images) and avoid the pitfall of becoming lost in the techy parts of making an image (to the detriment of creating your own unique images). But before you can get the most storytelling punch out of aperture, you need to understand how aperture works.
Luckily, aperture is like pie.
There’s a really simple concept behind aperture and – even more awesome – it’s connected to food. But first, you have to forget everything you know or everything someone has tried to teach you about aperture. Traditional teaching of aperture tells you nothing about creativity, so holding onto those ‘ought tos’ can be dangerous. Take a break, pour a cup of tea and clear your mind…are you ready? Here it is! Aperture is an awful lot like pie. Small numbers on your aperture dial like 1.8, 2.8 or 4 give you a small slice of pie (a small wedge of sharpness). On the other hand, large numbers on your aperture dial, like 16 or 22, return a big slice of pie (a large wedge of sharpness). This seems almost too easy but like with most of life’s basic truths, what appears deceptively simple is really a foundation for all those complicated decisions that follow. As a creative photographer, you get to decide just how much of the scene you want to appear in focus; do you want a thin or a large slice? Just like ordering pie! And of course whether you want a thin slice or a large slice is going to depend on where you want your viewer to look in your image and the mood you want to establish.
Examples of aperture in action.
Let’s see how aperture choice can impact your images. The photo on the left (below) was taken with an aperture of f1.4 giving a very thin wedge of sharpness. In fact, the only thing sharp is that rock in the foreground, and that is probably where your eye looked first in the image. The photo on the right was shot at f16 and everything appears sharp! While you probably still looked first at the snowy rock in the foreground, in the f16 image you likely spent more time looking at the mid-ground and background in the shot. There are a few basic principles of perception at work here. Humans tend to look first and spend more time looking at objects in an image that are large (especially if they appear in the lower part of an image), bright and detailed. So, you can use aperture, in conjunction with your understanding of composition, to not only direct where a viewer will look first in your image but also where they will look next. Just as important, you can create a completely different feel to an image just by changing your aperture number. In this example, which image seems softer or more subdued? Whether you want a dreamy feel or a ‘realistic’ or detailed feel in your image can be set in large part by your aperture number.
Let’s look at another example of the same scene shot with different apertures. In the two photos below the top image was made with a telephoto lens focused on the foreground tree and shot with an aperture of f5.6. Only the yellow tree is sharp and the trees in the background are blurry. The image has a softer mood and is more a contextual portrait of the yellow-leaved tree. The bottom image is sharp through out (f22 was used) and the photo is now about the forest.
You don’t always need everything in focus. For example, small aperture numbers on telephoto lenses create a wash of blur in the areas that are not in focus. This blur is called ‘bokeh’, but its effect is beautiful! You focus on the part of the scene you wish to appear sharp and choose a small number (for a small slice of sharpness) on your telephoto lens. In this shot, the foreground flower is sharp and the other flowers are not – but this image is about a soft mood and not a documentary shot of the details of the flowers so a small wedge of sharpness works to tell that story.
On the other hand, with a subject that is dynamic and full of detail you may want the largest slice of sharpness possible to render that detail throughout the frame. The photograph of the chairs below was taken with a large number on the aperture dial to give a large slice of sharpness. You might feel like you are wandering into the scene and to sit and enjoy the view to the sharp mountains in the background.
The three amigos.
Aperture is part of a triad of controls you have at your disposal to make compelling shots. The other two amigos in this triad are shutter speed and ISO. All three affect the look and feel of your photo, and their unique combination in an image is often referred to as an exposure. It can be challenging to learn about what one control does when all three controls are changing either because you are altering them in manual mode yourself or when the camera is doing it for you in a program or auto mode. We suggest you spend some time learning how the small aperture values, middle aperture values and large aperture values on your lenses affect the look of your photographs. The easiest way to do this is to switch your camera to aperture priority mode.
Aperture priority mode
The first step to really understanding aperture is to switch your camera to aperture priority mode. In this mode you are the boss of aperture. You tell the camera which aperture value you need for your creative vision and the camera automatically picks a shutter speed to return an average exposure. If you have your camera set to auto ISO, the camera will vary both the shutter speed and ISO to give an average exposure. All you need to be concerned about is aperture. Easy! If you’re just starting out, work in aperture priority mode, focus on the most important part of your scene, and then really pay attention in playback on your LCD to how your selection (small number or large number) influences where the viewer looks and the mood in your images.
From exposure to expression.
Understanding how aperture works can be confusing especially if you are concentrating on the technical components of aperture instead of thinking about what aperture really does on a creative level. That’s why a handy shortcut is to remember that aperture is like pie: a small aperture number returns a small slice of sharpness and a large aperture number returns a large slice of sharpness. But aperture is about much more than how much of the scene appears in focus. Good photographers understand the ability of aperture (in conjunction with composition) to direct the viewer’s gaze and establish mood in their images. There are a few more tips on using aperture effectively that you will come to know by playing and practicing – we know we’re still discovering the potential of aperture choice and we love to share what we learn with our readers! So, now that you’re initiated into the secret club of visual storytellers who count aperture as a handy tool in their artistic toolbox, there’s only one further question to ask yourself…where will your creative use of aperture take you?
To learn more about aperture, shutter speed and ISO be sure to pick up our Photography Fundamentals eBook collection