Depth of Field is one of the most useful things to understand in photography. It controls how much of your photo appears sharp, from the foreground to the background.
Once you understand DOF, you can deliberately choose whether you want:
- A blurry background behind a person
- Everything sharp in a landscape
- A subject isolated from the background
- Several surfers in focus
- A whole building sharp from front to back
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What is Depth of Field?
Depth of Field is the area of a photograph that appears acceptably sharp.
Think of it as a zone of sharpness running through your image.
Shallow Depth of Field
Only a small area is sharp.
For example:
Subject → SHARP → Background → BLURRY
This is commonly used for:
- Portraits
- Wildlife
- Flowers
- Detail shots
- Surfers against distracting backgrounds
Deep Depth of Field
A much larger area of the photograph is sharp.
Foreground → SHARP → Subject → SHARP → Background → SHARP
This is commonly used for:
- Landscapes
- Buildings
- City photography
- Group photographs
- Architecture
The Biggest Factor: Aperture
The easiest way to control DOF is with your aperture.
Your aperture is represented by the f-number:
| Aperture | Depth of Field | Background |
|---|---|---|
| f/1.4 | Very shallow | Very blurry |
| f/1.8 | Shallow | Blurry |
| f/2.8 | Shallow | Blurry |
| f/4 | Moderate | Some blur |
| f/5.6 | Moderate/deep | More detail |
| f/8 | Deep | Mostly sharp |
| f/11 | Very deep | Lots sharp |
| f/16 | Very deep | Almost everything sharp |
The important rule
Lower f-number = shallower DOF
Higher f-number = deeper DOF
So:
f/1.8 → lots of background blur
f/8 → much more of the image in focus
Why Does f/1.8 Give You More Blur?
At f/1.8, the aperture is wide open.
This creates a shallow area of acceptable focus.
For example, if you’re photographing someone at f/1.8:
Person’s eyes: sharp
Person’s ears: possibly slightly soft
Background: very blurry
This is why wide apertures are popular for portraits.
However, f/1.8 isn’t always the best setting.
If you’re photographing two people standing at slightly different distances, one person might be sharp while the other is outside your DOF.
Sometimes stopping down to f/2.8, f/4 or f/5.6 gives you a better photograph.
Distance Also Changes DOF
Aperture isn’t the only thing that matters.
The closer you are to your subject, the shallower the depth of field becomes.
Imagine photographing a flower from 20cm away.
At f/2.8 you might get:
Front of flower → SHARP
Back of flower → SOFT
Move several metres away and the amount of the scene that appears sharp increases.
This is particularly noticeable with:
- Macro photography
- Close-up photography
- Wildlife
- Portraits
Focal Length Matters Too
Your lens also affects how you perceive depth of field.
A telephoto lens can produce very strong background separation.
This is one reason your Sony 200-600mm can create beautifully isolated subjects.
For example:
200-600mm
Surfer → SHARP
Ocean/background → BLURRED
This can make the surfer stand out from the background.
However, remember that DOF isn’t simply determined by focal length alone. Subject distance, aperture, sensor size and your framing all interact.
DOF and Your Sony Cameras
Your Sony APS-C cameras, such as the:
- Sony A6000
- Sony A6400
- Sony A6700
are particularly good for learning DOF because you have control over aperture and focal length.
The APS-C sensor also gives you a useful balance between subject isolation and keeping enough of the subject sharp.
DOF for Surf Photography
This is particularly important for the type of photography you do.
When photographing surfers, you need to decide whether you want:
Isolated Surfer
Use something like:
f/4 – f/5.6
with a long focal length.
You can get:
SURFER = SHARP
BACKGROUND = SOFT
This helps draw attention to the surfer.
Multiple Surfers
If several surfers are at different distances, consider:
f/5.6 – f/8
This gives you more depth of field and increases your chances of keeping multiple subjects sharp.
Fast Action
Don’t forget that changing aperture affects your exposure.
If you move from:
f/4 → f/8
you’re letting in less light.
You may therefore need to compensate with:
- Faster shutter speed
- Higher ISO
- Or both
This is where DOF connects directly with the Exposure Triangle.
DOF and Shutter Speed
Depth of field doesn’t directly control motion blur, but changing aperture can force you to change shutter speed.
For example:
Starting point
f/4
1/2000 sec
ISO 400
You decide you want more depth of field:
f/8
You’re now letting in considerably less light.
To maintain exposure, you might need to increase ISO:
f/8
1/2000 sec
ISO 1600
This can be perfectly acceptable, particularly with modern cameras such as the A6400 and A6700.
DOF and ISO
ISO doesn’t directly change depth of field.
However, it allows you to maintain your chosen aperture and shutter speed.
For example, if you want:
f/8 for more DOF
1/2000 sec to freeze a surfer
but the image is too dark, increase ISO.
This is often preferable to dropping your shutter speed and introducing motion blur.
The DOF Sweet Spot
Don’t assume that the sharpest setting on your lens is always the best setting.
Many lenses produce excellent sharpness around:
f/5.6 – f/8
But it depends on the lens.
Very small apertures such as f/16 or f/22 can introduce diffraction, which can reduce overall image sharpness.
So don’t automatically use f/22 just because you want everything sharp.
Depth of Field Example
Imagine photographing a surfer.
f/2.8
Surfer: SHARP
Wave behind surfer: SOFT
Background: VERY BLURRY
Great for isolating the surfer.
f/5.6
Surfer: SHARP
Wave: MORE DETAIL
Background: SOME BLUR
Good general-purpose setting.
f/8
Surfer: SHARP
Wave: SHARPER
Background: MORE DETAIL
Useful when you want the environment to be part of the photograph.
The DOF Cheat Sheet
Remember these four things:
Want more background blur?
Lower f-number
→ f/1.8
→ f/2.8
→ f/4
Want more of the image sharp?
Higher f-number
→ f/5.6
→ f/8
→ f/11
Want stronger background blur?
Move closer to your subject
Want more background compression/isolation?
Use a longer focal length and adjust your distance/framing appropriately.
Beginner DOF Settings
| Type of Photography | Starting Aperture |
|---|---|
| Portrait | f/1.8–f/2.8 |
| Wildlife | f/4–f/6.3 |
| Surf photography | f/4–f/8 |
| Flowers | f/2.8–f/5.6 |
| Street photography | f/4–f/8 |
| Buildings | f/5.6–f/8 |
| Landscape | f/8–f/11 |
| Group photo | f/5.6–f/8 |
| Macro | f/8–f/16 |
These are starting points, not rules.
A Simple DOF Experiment
You can learn DOF very quickly with your Sony camera.
Find a row of objects at different distances — bottles, toys, books or even people.
Put your camera on Aperture Priority (A).
Take three photographs:
Photo 1
f/2.8
Photo 2
f/5.6
Photo 3
f/8
Keep the camera and subject in roughly the same position.
Then compare the images.
You’ll immediately see how increasing the f-number changes the amount of the scene that appears sharp.
DOF + Autofocus
Depth of field and autofocus work together.
For portraits, make sure you’re focusing on the eye.
For surf photography, your subject may be moving rapidly, so continuous autofocus such as AF-C can be useful.
The important thing to remember is:
A photograph can have a large depth of field but still be out of focus.
DOF doesn’t replace accurate focusing.
The One Rule I’d Remember
If you’re just starting out, remember this:
f/1.8 = small area sharp + lots of blur
f/4 = useful balance
f/8 = much more of the scene sharp
And don’t forget:
DOF is controlled by more than aperture.
It is affected by the combination of:
Aperture + subject distance + focal length + sensor/camera format + framing.
DOF Quick Reference
Want creamy background blur?
📷 Wide aperture
f/1.4 – f/2.8
Want a balance between subject and background?
📷 Medium aperture
f/4 – f/5.6
Want lots of the scene sharp?
📷 Narrow aperture
f/8 – f/11
For your Sony A6400/A6700 and surf photography, I’d generally start around f/5.6–f/8 when you need reliable subject detail, then open the aperture when you specifically want more separation from the background.
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