Aperture is one of the three key elements of exposure in photography — along with shutter speed and ISO. It controls how much light enters your camera and how much of your image appears in focus.
Whether you’re using a DSLR, mirrorless camera, or smartphone with manual controls, understanding aperture will help you create photos with beautiful background blur, sharp landscapes, and everything in between.
In this complete guide, you’ll learn exactly what aperture is, how it works, and how to use it creatively to improve your photography.
What Is Aperture?
Aperture refers to the opening in your lens that lets light into your camera. It works just like the pupil in your eye — it can widen or narrow depending on lighting conditions.
Aperture is measured in f-stops, such as f/1.8, f/2.8, f/4, f/5.6, and so on.
- Wide aperture (e.g., f/1.8) = more light = shallow depth of field = more background blur
- Narrow aperture (e.g., f/11) = less light = deep depth of field = more of the image in focus
📌 Important: A smaller f-number means a wider opening. It sounds backward, but it’s just how the scale works.
How Aperture Affects Your Photos
Aperture impacts two major things:
1. Exposure
- A wide aperture lets in more light → Brighter image
- A narrow aperture lets in less light → Darker image
2. Depth of Field
- Wide aperture (f/1.8–f/2.8) = Shallow depth of field = Subject in focus, background blurry
- Narrow aperture (f/8–f/16) = Deep depth of field = Everything in focus from front to back
This makes aperture not just a technical tool — but a creative choice.
Examples of Aperture in Action
| Aperture | Scene Type | Result |
|---|---|---|
| f/1.8 | Portrait | Subject sharp, background blurry (bokeh) |
| f/2.8 | Food/Product Photography | Focused object, soft background |
| f/5.6 | Street photography | Moderate focus range |
| f/8–f/11 | Landscapes, Architecture | Everything sharp from front to back |
| f/16+ | Bright scenes, Sunstars | Maximum sharpness (watch for lens diffraction) |
📌 Portraits often look best at f/1.8 to f/2.8
📌 Landscapes often look best at f/8 to f/11
What Is Bokeh?
Bokeh refers to the aesthetic quality of the blur in the out-of-focus areas of a photo.
- More noticeable with wide apertures (f/1.4–f/2.8)
- Depends on lens design, distance from background, and light points
Beautiful bokeh is popular in portraits, food shots, and creative photography — it helps separate your subject from the background.
How to Control Aperture on Your Camera
DSLR or Mirrorless:
- Use Aperture Priority Mode (A or Av): You set the f-stop, camera adjusts the rest
- Use Manual Mode (M): You control everything
- Adjust with a dial or touchscreen, depending on your camera model
Smartphone:
- Use Pro Mode in apps like Halide, ProCamera, or Lightroom Mobile
- On some phones, Portrait Mode simulates shallow depth of field
- True optical aperture control is only available on select smartphones
Factors That Affect Depth of Field (Beyond Aperture)
While aperture is the main control, depth of field is also influenced by:
1. Distance from Subject
- The closer you are, the shallower the depth of field
- Step back for more in-focus areas
2. Focal Length
- Longer lenses (e.g., 85mm) produce more blur than wide-angle lenses (e.g., 24mm)
3. Sensor Size
- Cameras with larger sensors (e.g., full-frame) create shallower depth of field at the same settings compared to smartphones or crop-sensor cameras
Tips for Using Aperture Creatively
Portraits
- Use f/1.8–f/2.8
- Focus on the eyes
- Keep the background distant for better blur
Landscapes
- Use f/8–f/11
- Focus one-third into the scene (hyperfocal distance)
- Use a tripod if needed for longer shutter speeds
Street Photography
- Use f/5.6–f/8
- Keeps more of the scene in focus
- Helps capture quick moments without refocusing
Macro Photography
- Use f/5.6–f/8 for sharp focus on close subjects
- Depth of field is extremely shallow — every millimeter matters
How Aperture Affects Lens Choice
Some lenses have a fixed maximum aperture, like f/2.8, while others change based on zoom, like f/3.5–5.6.
Prime Lenses:
- Fixed focal length (e.g., 50mm)
- Usually have wide apertures (f/1.8 or wider)
- Ideal for portraits and low light
Zoom Lenses:
- Variable focal length (e.g., 18–55mm)
- Often have narrower max apertures
- More flexible, but less light for blur
📌 Tip: A 50mm f/1.8 lens is one of the best and most affordable tools for learning aperture creatively.
Common Mistakes and How to Fix Them
❌ Overusing wide apertures
- Sometimes too much blur can hide important context
- Try stopping down to f/4 or f/5.6 for balance
❌ Using narrow apertures in low light
- At f/16, your image may be too dark unless you slow the shutter or raise ISO
❌ Forgetting to focus precisely
- At f/1.8, only a tiny slice of the image is sharp — focus on the eyes in portraits
Practice Exercises
Exercise 1: Bokeh Test
- Use a wide aperture (f/1.8–f/2.8)
- Photograph a subject close to the lens
- Place lights or textured background behind
- Observe the blur and shapes
Exercise 2: Landscape Depth Test
- Use f/4, f/8, and f/16 for the same scene
- Focus one-third into the frame
- Compare sharpness front to back
Exercise 3: Same Subject, Multiple Apertures
- Photograph one object at f/2.8, f/5.6, and f/11
- Watch how background and sharpness change
Final Thoughts: Aperture Is Creative Control
Aperture is more than a technical setting — it’s how you decide what the viewer focuses on, and how much of the scene tells the story.
Whether you want a dreamy portrait or a sweeping landscape, controlling aperture lets you:
- Balance light
- Shape focus
- Create emotion
Master it, and your photography will become more intentional, expressive, and professional — one frame at a time.