Depth of Field in Film: How to Get Shallow or Deep Focus

Depth of field is how much of your shot, from near to far, looks sharp. Open the aperture, move closer and use a longer lens, and you get shallow depth of field: a thin slice in focus with a soft background. Close the aperture, go wider and step back, and you get deep focus, where everything from foreground to horizon is crisp.

This guide shows you how to choose the look on purpose. You will get the three factors that control depth of field, an f-stop chart for a 50mm lens, how sensor size changes the result, step-by-step settings for shallow and deep focus, and how to get a blurry background on a phone.

What depth of field means in cinematography

When you focus on something, only one distance is perfectly sharp. Things slightly nearer or farther look sharp enough that the eye accepts them. That zone of acceptable sharpness is depth of field, and it stretches from a near limit to a far limit. About one third of it usually sits in front of the focus point and two thirds behind it, which is why focusing a bit in front of the scene helps for deep focus.

Why it matters for story:

• Shallow depth of field isolates a face, makes a character feel alone, or hides a messy location.
• Deep depth of field lets you stage action at several distances and keeps the environment in the story.

In Citizen Kane (1941), cinematographer Gregg Toland used deep focus so that young Charles plays in the snow in the distance, framed through a window, while the adults sign his future away in the foreground. All of it is sharp, so the viewer can read every layer. On the other end, Stanley Kubrick shot the candlelit scenes in Barry Lyndon (1975) with ultra-fast Zeiss lenses at about f/0.7, which makes focus razor thin.

The three factors that control depth of field

1. Aperture

Aperture is the opening in the lens, measured in f-stops. A lower f-number (f/1.4) means a larger opening and shallower depth of field. A higher f-number (f/11) means a smaller opening and deeper depth of field.

Aperture is the quickest control because you can change it in seconds. It also changes exposure, so if you open up for blur in bright sun you will need ND filters or a faster shutter to avoid blowing out the image. On a film set, ND filters are standard for exactly this reason.

2. Distance to the subject

The closer the camera is to the subject, the shallower the depth of field. A close-up at f/2.8 can have only a few inches in focus, while the same f-stop on a wide shot of a street might keep everything sharp.

This is why a face tight in the frame can look very soft behind the eyes, and why an actor leaning toward the camera can drift out of focus.

3. Focal length

At the same distance and the same aperture, a longer focal length gives shallower depth of field. A telephoto lens also magnifies the background blur, which makes it look even softer.

There is a subtlety many guides skip. If you change the focal length and then move the camera to keep the same framing, the depth of field on the subject stays nearly the same. What changes is the background: a longer lens shows less of it and enlarges it, so it looks blurrier. So when people say long lenses give shallow depth of field, they are right about the look, even if the physics are a bit more complicated.

How the numbers play out

These are approximate depth of field zones for a full-frame camera with a 50mm lens focused at 10 feet (about 3 meters). They assume standard calculations and are for comparison, not for pulling focus on set.

Aperture	Approximate depth of field
f/1.4	about 1 foot
f/2.8	about 2 feet
f/5.6	about 4 feet
f/11	about 9 feet

Each time you close down two stops, depth of field roughly doubles. At f/1.4 and 10 feet, a subject who sways forward or back by a foot will drift out of focus. That is why close-ups at wide apertures need a focus puller or very careful blocking.

Sensor size and depth of field

Sensor size changes depth of field because it changes which lens you need for the same framing. A larger sensor needs a longer lens (or a closer camera) to get the same field of view, and that makes depth of field shallower at the same f-stop.

Rough equivalents for the same framing:

• Full frame, 50mm at f/2.8 looks similar to
• Super 35 / APS-C, about 35mm at f/2 and
• Micro Four Thirds, about 25mm at f/1.4.

In practice:

• Full frame and large format give you the easiest shallow look, which is why cameras like the Sony FX series and ARRI Alexa 65 are popular for blurry backgrounds.
• Super 35 (the traditional cinema size) is a good middle ground.
• Micro Four Thirds has deeper focus, which makes it forgiving for run-and-gun work.
• Phones have much smaller sensors, so most shots are very sharp unless you do something about it. More below.

If you are choosing a camera, see our guide on how to choose the right camera for your film project.

Practical settings for shallow and deep focus

For shallow depth of field

1. Open the aperture to the widest your lens allows, typically f/1.4 to f/2.8.
2. Get closer to the subject.
3. Use a longer lens, such as 50mm, 85mm or 135mm on full frame.
4. Move the subject away from the background. Ten feet of separation does more than two stops of aperture.
5. Use ND filters to keep the shutter at 180 degrees (twice your frame rate) in bright light.

For deep depth of field

1. Close the aperture to around f/8 or f/11. Going far beyond f/16 can soften the image from diffraction.
2. Use a wide lens, 24mm or wider on full frame.
3. Step back from the nearest subject.
4. Focus about a third of the way into the scene, or use hyperfocal focus (the closest distance that keeps infinity acceptably sharp).
5. Add light. Small apertures need more of it.

When to choose which

• Dialogue close-ups: shallow, so the eyes are the focus.
• Establishing shots: deep, so the audience can read the space.
• Handheld action: deeper than you think. Shallow focus on a moving camera is hard to keep sharp. See handheld vs stabilized cinematography.
• Moving camera shots: if the camera travels, check camera movements for ideas on focus pulls and rack focus.
• Low light: you may be forced to shoot wide open, so plan your blocking to suit shallow focus.

For how focus choices fit into your coverage, our shot list guide lets you note the lens and aperture you want for each shot.

Common depth of field mistakes

• Shooting everything wide open. It looks nice in a test and becomes a nightmare when actors move. Stop down a notch.
• Ignoring the background. If the background is a busy bright window, even a shallow blur will look noisy. Fix the background first.
• Soft focus mistaken for shallow focus. If nothing is sharp, check your focus point, not your aperture.
• Forgetting the focus puller. If you shoot at f/1.4, you need someone pulling focus, or you need a monitor with focus peaking.
• Overcorrecting in post. Software can add background blur, but hair and edges often betray it.

How to get shallow or deep depth of field on a phone

Phone cameras have tiny sensors and short lenses, so depth of field is deep by default. A typical main phone camera behaves like roughly f/5 to f/8 on a full-frame camera, even though the lens is marked f/1.8 or so. That is great for keeping everything sharp, and tough for natural blur.

Get shallow depth of field on a phone

• Use the telephoto lens (2x, 3x or 5x on many phones), because it gives more compression and a softer background.
• Get close to your subject and keep the background as far away as possible.
• Tap to focus and lock exposure so the phone does not hunt.
• Try Cinematic mode (iPhone) or similar video blur modes on Android. They use depth data to simulate blur, and on iPhone you can change the blur and focus point after recording. The edges around hair and glasses can look artificial.
• Add a clip-on lens such as an anamorphic or portrait adapter if you want a more optical look.

Get deep depth of field on a phone

• Shoot with the main or ultra-wide lens.
• Turn off Portrait and Cinematic modes.
• Shoot in bright light so the phone uses a fast shutter and low ISO.
• Keep subjects at least a few feet apart from the camera.

If you shoot a lot on a phone, an app that gives manual control, like Blackmagic Camera, makes it easier to lock focus and exposure for consistent results.

Fixing depth of field in post

You cannot add real depth of field in editing, but you can imitate it. Many editing and grading apps include depth map or subject isolation tools that blur backgrounds. These work for light touch-ups on clean shots. They tend to fail on fine hair, glasses and moving subjects. Better to get the look in camera, and use the tools for emergencies. For more on finishing, see color grading vs color correction and the free video editing software guide.

If you are new to the wider craft, what is cinematography puts depth of field alongside lighting, composition and lenses.