Differential focus — guiding attention with blur
You’ve probably seen photos where the subject is crisp, but the background melts into soft blur. That technique is called differential focus, and it’s one of the best ways to isolate your subject and control where the viewer looks.
With today’s smartphone cameras and portrait modes, you don’t need a DSLR to create this effect—you just need to know when and how to use it.
What is differential focus?
It’s the use of selective sharpness to make one part of the photo stand out while everything else blurs softly. Your subject pops, the background fades, and your message becomes crystal clear.
It’s different from natural depth of field (based on aperture)—with smartphones, it's mostly software-driven.
When to use differential focus
Portraits: Emphasize eyes and expression
Product photos: Highlight features
Details in cluttered environments: Simplify complex backgrounds
Storytelling: Focus on action or emotion
How to create it on your phone
Use Portrait Mode
Activate it in your camera app. Position your subject well and step back slightly.Tap to focus
Tell your phone exactly where to lock sharpness.Use editing tools
Apps like Snapseed and Lightroom let you add blur or clarity selectively.Work with light
Bright subjects on darker backgrounds improve the blur separation.
When not to use it
When the background tells part of the story
When artificial blur looks too obvious or unnatural
When you need full scene clarity (e.g. landscapes, group shots)
Balance focus and blur based on purpose.
Did you know?
Differential focus has been a hallmark of portrait photography for decades. Classic 85mm lenses are prized for their shallow depth of field, and now smartphones simulate this effect with computational power.
Tips to improve results
Clean your lens! Smudges affect clarity.
Step back and zoom slightly for more natural blur.
Use contrast (light or color) to separate subject and background.
Common mistakes
Focusing on the wrong part of the subject
Artificial blur around edges
Too much separation, making it feel fake
Preview your shot before capturing, and adjust your distance and framing.
Related techniques
Use the search bar above to search for any composition technique, including the below:
Isolation
Selective Sharpness
Fill the frame
Conclusion
Differential focus gives your images focus—literally and emotionally. It helps you simplify, emphasize, and guide your viewer’s eye to what matters.
📘 Learn how to master this and 100+ more techniques in my book Stronger Photo Composition 4-Step System.
