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 and the diaphragm are adjusted according to the f-stop or aperture choice.
Aperture Basics for Photographers
The aperture, or f-stop, 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 up the lens diaphragm, or blades, more light is admitted, such as f/2.8. For example, when you stop down the aperture to f/16, less light is admitted.
Reviewing the chart 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 observe the exposure results and effects.
Also, could you consider the depth of field as you observe how much of the scene contains intentional focus? In other words, observe 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 way of:
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 is indicated by the letter “A”. Changing the mode dial to the letter M changes the camera setting to Manual Mode.
The Aperture Makes a Difference
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 called 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, at f/8.
Also, notice how the intermittent cloud cover creates relatively even exposure without the extremes of deep shadows or blown-out highlights.
A mountain landscape captured in detail and greater depth of field at f/11.
An expansive scene photographed at f/8.
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.
Photographed at f/6.7, there is more detail in the foreground with a shallow depth of field in the background.
A dragonfly is highlighted with a shallow depth of field at f/6.3.
A bee on a flower photographed at f/2.8.
Aperture and the Exposure Triangle
You may have encountered the Exposure Triangle as a photography term. Aperture, shutter speed, and ISO make up the triangle. These three settings can be adjusted singularly or in combination to help achieve the result for your pictures in terms of exposure and capturing the subject or scene in the way you envision.
This is an example of using an aperture of f/10 for a greater depth of field and the exposure triangle to expose for the light conditions.
Aperture Basics for Photographers Can be Confusing, Here’s Why
There are times when we want to create an intentional blur, or "boh-kay,” but it just doesn’t seem to work, even with a wide-open aperture. Similarly, sometimes, a more stopped down aperture, such as f/10, creates a beautiful blur.
Why is that?
Some camera lenses have limitations that make it highly challenging to blur the background.
One way around this is to change your point of focus, either to a point closer to or farther away from you.
A lens with a more extended focal range, or amount of zoom, will create a shallow depth of field, which is affected by lens compression.
Lens compression is a visual effect that makes the background appear closer to the subject, and the distance between the background and foreground seems to be reduced.
Lens compression at work with an aperture of f/10, and a focal length of 400mm.
For example, a camera lens is often called a “kit lens” when it’s included in a camera kit with the body. This lens frequently has an 18-55mm focal length for a wide-angle view and minimal zooming capabilities. It has challenged many beginner photographers who want to blur the background but struggle to achieve it.
In comparison, the lens used to photograph the spider web at f/10 has a focal length of 80-400mm. When photographed with the extreme amount of zoom at 400mm, compression creates a shallow depth of field in this situation, even at f/10.
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.
It is useful for obtaining a faster shutter speed to capture action.
Understanding the basics of the aperture 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.
In my online course, 37 Ways to Improve Your Photos In Minutes, I provide more in-depth information, complete with practice exercises and reference slides if you would like more.
