When you first pick up a DSLR or mirrorless camera, all those buttons and settings can feel a little intimidating. You might hear photographers talk about “fast glass” or “shooting wide open”, but for beginners, the first big question is often: What exactly is aperture?
Understanding aperture is one of those “lightbulb moments” in photography. It’s the key to moving beyond Auto mode and creating shots with beautifully blurred backgrounds and professional-looking depth.
In this quick-start guide, we’ll explain what aperture is and how aperture affects depth of field so you know how to take full creative control of your images. By the end, you’ll be ready to craft the shots you’ve always imagined.
What Does Aperture Mean?
At its simplest, aperture is the opening in your camera lens that allows light to reach the sensor. Think of it like the pupil of your eye:
- In bright light, your pupil shrinks to protect your vision.
- In the dark, your pupil expands to let in as much light as possible.
In photography, we measure this opening in f-stops (e.g., f/1.8, f/8, f/11).
The F-Stop Paradox
The most confusing part for beginners is that the numbers feel backwards: just remember that the smaller the f-number, the 'bigger' the opening.
- A small f-number (like f/1.8) means a large opening.
- A large f-number (like f/22) means a small opening.
Top Tip: If you want more light or more blur, go for the smaller number!
The Direct Link: Aperture and Depth of Field
Aperture controls light, but it also determines your Depth of Field (DoF). This is simply the 'focus zone' of your photo. It is the setting that decides how much of your image stays sharp and how much of it becomes blurry.
1. Shallow Depth of Field (The "Blurry" Look)
When you use a wide aperture (a small f-number like f/1.8 or f/2.8), you create a shallow depth of field. This means only a tiny slice of your image is sharp, while the background and foreground melt into a soft blur.
- Best for: Portraits, wildlife, and macro photography where you want your subject to "pop."
- Recommended Gear: "Prime" lenses, such as a 50mm f/1.8, are famous for achieving this effect affordably.
2. Deep Depth of Field (The "Sharp" Look)
When you use a narrow aperture (a large f-number like f/11 or f/16), you create a deep depth of field. This ensures that everything from the pebbles at your feet to the mountains in the distance remains crisp and clear.
- Best for: Landscapes, architecture, and group photos.
- Recommended Gear: A sturdy tripod is often helpful here, as smaller apertures let in less light, requiring slower shutter speeds.
For example, the first image below shows a shallow depth of field, and the second image shows a deep depth of field:
Credit: GERMAN SUAREZ (Pexels)
Credit: Stein Egil Liland (Pexels)
How to Practice: The "Aperture Priority" Trick
If you’re ready to see the difference for yourself, you don’t need to go full "Manual" just yet.
- Turn your camera dial to A (or Av on Canon/Pentax). This is Aperture Priority Mode.
- You control the aperture (the f-number), and the camera automatically handles the rest.
- Find a subject (like a flower or a friend) and take one photo at the lowest f-number your lens allows. Then, take the same photo at f/11.
Compare the two, and you’ll instantly see how aperture transforms the mood of the shot.
Which Aperture Should You Use?
- For "Bokeh" (Background Blur): Use f/1.4, f/1.8, or f/2.8.
- For Everyday Snaps: Use f/5.6 or f/8 (often called the "sweet spot" for lens sharpness).
- For Vast Landscapes: Use f/11 or f/16.
Ready to Upgrade Your Glass?
Now that you know what aperture means, you might find that your standard "kit lens" has its limits - especially in low light or when hunting for that creamy background blur.
Whether you’re looking for a "fast" prime lens or a versatile zoom, our team at Harrison Cameras is here to help. Explore our range of new and used lenses to find the perfect match for your photography journey.