Aperture Basics for Photographers
When you’re learning photography, you may have encountered the term aperture or f-stop. But what is it, how do you adjust it, and how does it affect your photos? I’ll break it down in simple terms for you.
What is Aperture?
Aperture refers to the opening in your camera lens. Light enters through this lens opening to hit your camera sensor or the film in a non-digital camera. The aperture is measured in numbers, and those numbers are referred to as f-stops, such as f/2.8, f/5.6, or f/11, for example. It is controlled with an aperture-specific camera setting.
The f-stop indicates how big or small the opening is and determines how much light enters through the lens.
Overlapping lens blades adjust according to the f-stop, or aperture, choice.
How Aperture Affects Your Photos
The aperture controls the amount of light that enters the camera and can be used to affect the exposure (how bright or dark your photo is). When you open the aperture, more light is admitted. When you stop down the aperture to f/16, for example, less light is admitted.
When you review the example below, observe how the f-stop corresponding number relates to the lens opening size as the overlapping lens blades move according to the aperture camera setting.
An aperture, or f-stop of f/1.4, admits more light than f/5.6 or f/16, for example. (Slide from my online course, 37 Ways to Improve Your Photos in Minutes).
Because the Aperture controls the amount of light, the choice of f-stop controls and affects:
Exposure
Depth of Field
Your creativity
Assists with shutter speed, such as when you require a faster shutter speed to capture action.
Assists with obtaining a slower shutter speed when you want to blur water, for example.
When you look at your pictures and notice how light or dark they are, you are observing the exposure results and effects.
Additionally, consider the depth of field as you observe how much of the subject or scene has intentional focus. In other words, how much of your subject or scene is in focus from the foreground to the background?
How the Aperture is Controlled
The aperture can be controlled by the following:
In Automatic Camera Mode, the camera makes choices and adjustments based on the interpretation of the scene or subject.
When utilizing the camera’s semi-automatic Aperture Priority Setting, you, as the photographer, decide on the f-stop value or number.
Shooting in the camera’s Manual Mode as you, once again, decide on the f-stop value when considering the exposure results, depth of field, and, as necessary, the shutter speed
An example of the Aperture Priority setting as indicated by the letter “A”. Changing the mode dial to the letter M changes the camera setting to the Manual Mode.
Why Aperture Matters for Your Photos
When you observe your photos and those of others, please take your time to notice the overall result. For example:
Is the exposure pleasing, with no blown-out bright highlights or details lost in the shadows?
Is the depth of field greater or shallower?
When considering aperture basics for photographers and the aperture possibilities:
Intentional blur—subjects and scenes with intentional blur in the background that emphasize the main subject. This effect is referred to as a shallow depth of field and is often called bokeh (pronounced "boh-kay").
Landscapes – often have a greater depth of field as everything from the foreground to the background is sharp and in focus.
In low-light conditions shooting with a wider aperture (smaller f-stop number) assists in capturing the desired exposure without necessarily needing to change the ISO.
A landscape example of a greater depth of field with focus and clarity from the foreground to the background.
Depth of field refers to how much of your photo is intentionally focused from the front to the back.
The smaller the f-number, or f-stop, the greater the amount of light admitted through the lens. This is helpful for low-light conditions or creative uses such as blurring the background, which is a shallow depth of field, or bokeh.
The more significant the f-number, the less light is admitted, which is optimum for keeping everything focused, such as what you see on a postcard or landscape images.
An example of a shallow depth of field with foliage blurred in the background.
Creative use of the camera aperture setting to blur and simplify the background to have the subject stand out.
Aperture and the Exposure Triangle
You may have encountered the Exposure Triangle as a photography term. Aperture, shutter speed, and ISO are part of the triangle. These three settings can be adjusted singularly or in combination to help achieve the end result for your pictures, both in terms of exposure and in terms of capturing the subject or scene in the way you envision.
An example of using the aperture f-stop for a greater depth of field and a correct exposure.
In Conclusion
With an introduction to aperture basics for photographers, you have discovered that the Aperture:
Relates to the amount of light admitted through the lens.
It’s a key tool in controlling the light and look of your photos.
Can be used creatively, to affect the depth of field.
Is helpful in low-light situations.
Is useful for obtaining a faster shutter speed to capture action.
Understanding the aperture basics for photographers and how it works will help you take photos more creatively and precisely. Whether blurring the background in a portrait, keeping everything sharp in a landscape, or using it to assist with correct exposure or capturing action, experimenting with f-stops gives you more control over your photography.
Referencing your camera manual.
Your camera manual briefly introduces the camera aperture setting, what to look for, and how to adjust it to help you get started with your particular camera model.