As creators, we’ve all been there—the dream of capturing professional-looking videos on a smartphone. One of the most coveted effects for creating that cinematic look is the blurry background, also known as bokeh.
But achieving this effect isn’t just about background blur—it also depends on how your smartphone processes color and depth. Learn more about bit depth in smartphone filming to ensure the best video quality.
In the past, achieving this effect meant you needed high-end professional cameras with large sensors and wide apertures. Still, with the proper techniques and settings, you can get a stunning blurry background on your smartphone.
Let’s examine the four main factors influencing background blur and how you can master them, even with a smartphone.
1. Aperture
The first thing you need to understand is aperture. In photography and videography, the aperture controls how much light enters the lens and plays a significant role in the depth of field.
The lower the aperture number, the more light you can let in, and the more likely you’ll get a blurry background.
On the other hand, a higher aperture number, like f/5.0 or f/10, will keep more of the scene in focus, making the background appear sharper.
Professional cameras can easily adjust the aperture to control the depth of field, but smartphones come with fixed apertures, which means you can’t manually change them.
However, this doesn’t mean you’re stuck with flat, dull videos. Here’s the catch: most smartphones (like iPhones) have a fixed aperture of f/1.8 to f/2.2 on their primary lenses, which is an excellent start for achieving some background blur.
While you’re filming, smartphones are typically designed to optimize exposure and lighting in automatic settings, but knowing about aperture helps you understand why some phones look better than others in terms of background blur.
Larger sensors (like the primary 1x lens on most smartphones) also help you achieve a softer, more blurred background.
2. Focal Length
Next up is focal length—this is where things get fun. The higher the focal length, the more “zoomed in” your footage will appear, and the more pronounced the background blur will be.
For example, a wide focal length, like 16mm or 24mm(typical for ultra-wide lenses), will show much of the background, keeping it relatively sharp.
But when you switch to a higher focal length, say 30mm or 85mm, the background blur (also known as bokeh) increases.
Here’s the thing, though: smartphones come with multiple lenses, each with a different focal length.
The primary lens (usually the 1x lens) has a larger sensor and provides a more natural perspective. In contrast, the telephoto lens offers more zoom but often comes with more compression, leading to even blurrier backgrounds.
If you’re looking to elevate your videos further, an anamorphic lens can provide that signature Hollywood widescreen look while maintaining natural bokeh.
If you want to achieve that iconic blurry background, opt for your smartphone’s primary lens (1x). While the telephoto lens may give you more zoom, the 1x lens, thanks to its larger sensor size, is your best bet for natural-looking blur.
3. Distance Between the Subject and the Background
This is the game-changer: distance. The farther you get your subject from the background, the blurrier the background will appear.
This is why filming in larger spaces or at a diagonal angle in a room helps create more depth and separation between your subject and the background.
In tighter spaces, like filming against a wall, you’ll notice that the background doesn’t blur as much. But the more space you have between your subject and the background, the more out-of-focus the background will be.
To maximize this, move the subject away from the background or, if possible, film in a larger area to give yourself more room to work with. You can also use additional smartphone lenses for creators to enhance depth and compression in your shots.
Large, open outdoor spaces are perfect for creating a dreamy, blurred background with smartphones.
4. Using Smartphone Features to Mimic Professional Lenses
The fourth factor is cinematic software modes, which smartphones have integrated to simulate the blurry background look.
Let’s face it—smartphone lenses can only go so far when it comes to creating that beautiful depth of field, but manufacturers have found a way to mimic this look through software.
iPhones, for example, offer Cinematic Mode, which automatically blurs the background by identifying the subject in the frame and then applying a digital blur.
Similarly, Android phones like Samsung have the Portrait Video Mode, which works similarly by enhancing the background blur for a shallow depth of field.
While this software-based approach doesn’t match the performance of professional cameras with large sensors, it’s a great shortcut to achieving the dreamy bokeh effect, especially if you’re filming for social media or small-screen content.
Remember that the effect might not be perfect—especially around the edges of the subject’s hair or in complex scenes—but it can be good enough for most casual video projects.
Pro Tip: Locking Exposure for Better Results
One challenge when filming with cinematic modes (whether on an iPhone or Android) is that the auto-exposure can change while you’re filming, disrupting your shot.
To maintain consistent lighting, check out how to balance exposure in dark scenes for expert tips on keeping your footage clear and well-lit.
To keep things consistent, lock your exposure before you start recording. Tap and hold the focus or exposure point on your screen to lock it.
This ensures that your background blur stays consistent throughout the shot and avoids those sudden changes in exposure that can make your video look unprofessional.
Combining Techniques for Better Results
While cinematic mode is a great tool, relying on software for the blurry background effect is not always necessary.
You can achieve impressive results with just your smartphone by combining the right focal length, aperture (even if it’s fixed), and distance between the subject and the background.
If you want more control, third-party apps like Beastcam and Moment Pro Camera let you manually adjust settings like shutter speed, ISO, and focus, giving you more creative power over your footage.
Final Thoughts
Achieving that iconic blurry background on your smartphone might initially seem tricky. Still, with the proper understanding of aperture, focal length, distance, and cinematic modes, you can create professional-looking shots without needing an expensive camera.
While smartphone cameras might not offer the same level of control as professional DSLRs or mirrorless cameras, you can still achieve stunning results.
So, remember: don’t stress over getting the “perfect” blurry background. Focus on composition, lighting, and storytelling; the rest will follow.