Subject Distance to Depth of Field Calculator

Enter your focal length, aperture, subject distance and circle of confusion to calculate near and far focus limits, total depth of field, hyperfocal distance and magnification.

Created by Luis GonzalezLast updated: May 9, 2026

How to Use This Calculator

1
Input your lens focal length
Enter the focal length of your lens in millimeters (e.g., 50 mm, 85 mm).
2
Specify the aperture (f-number)
Provide the f-stop used during the shot; larger numbers yield greater depth of field.
3
Enter subject distance
Input the distance from your camera's sensor plane to the subject in meters.
4
Define circle of confusion
Enter the maximum acceptable blur diameter in millimeters (e.g., 0.030 mm for full-frame).
5
Review your depth of field metrics
Examine the calculated depth of field, near/far focus limits, and hyperfocal distance.

Example Calculation

A photographer is setting up a portrait shot and wants to calculate the depth of field with specific lens and camera settings.

Focal Length

50 mm

Aperture (f-number)

f/2.8

Subject Distance

3 m

Circle of Confusion

0.030 mm

Results

0.599 m

Tips

Control Depth of Field with Aperture

To achieve a shallower depth of field (like 0.599 m), use a wider aperture (smaller f-number, e.g., f/1.8 or f/1.4). For a deeper depth of field, use a narrower aperture (larger f-number, e.g., f/8 or f/11).

Adjust Subject Distance for Impact

Moving closer to your subject (reducing 'Subject Distance' from 3m) will significantly decrease your depth of field, creating more background blur. Moving further away will increase it, bringing more of the scene into focus.

Understand Circle of Confusion

The 0.030 mm 'Circle of Confusion' is crucial for calculation accuracy. If shooting with an APS-C sensor, use a smaller CoC (e.g., 0.019 mm) to get more precise depth of field results, as smaller sensors require tighter focus.

The Subject Distance to Depth of Field Calculator is an indispensable tool for photographers seeking precise control over their image's focus. By entering your lens's focal length, aperture, subject distance, and the circle of confusion, you can instantly calculate the depth of field, near and far focus limits, hyperfocal distance, and magnification. This resource is invaluable for artistic and technical planning, helping a photographer understand that with a 50mm lens at f/2.8, a 3-meter subject distance, and a 0.030mm CoC, the depth of field will be 0.599 meters in 2025.

Mastering Selective Focus in Visual Storytelling

Mastering selective focus through depth of field (DoF) is a powerful technique in visual storytelling, allowing photographers to draw the viewer's eye to specific elements within an image. With a 50mm lens at f/2.8, a subject 3 meters away yields a shallow DoF of 0.599 meters, effectively isolating the subject from a blurred background, a common technique for compelling portraits. Conversely, using a narrower aperture like f/11 for a landscape ensures a deep DoF, keeping elements from the foreground to the distant horizon sharp. Professional photographers often choose apertures like f/1.4-f/2.8 for portraits to create creamy bokeh, while f/8-f/16 are favored for landscapes to maximize sharpness. Understanding these aperture choices and their impact on DoF is fundamental to achieving desired artistic effects and conveying specific narratives through imagery.

Deconstructing Depth of Field: The Lens Equation

This calculator uses established optical formulas to determine the depth of field and related focus parameters, translating lens settings into precise distances.

H = (Focal Length^2) / (Aperture (f-number) × Circle of Confusion) + Focal Length
Near Focus Limit = (H × Subject Distance) / (H + (Subject Distance - Focal Length))
Far Focus Limit = (H × Subject Distance) / (H - (Subject Distance - Focal Length))
Depth of Field = Far Focus Limit - Near Focus Limit

All distances are converted to millimeters for calculation, then back to meters for results. H represents the hyperfocal distance. Near Focus Limit and Far Focus Limit define the boundaries of acceptable sharpness, and Depth of Field is the total range between them. For a 50mm lens at f/2.8 with a 3m subject distance, the DoF is 0.599 m.

💡 Understanding how lens and sensor parameters affect your image is crucial. Our Megapixel to Print Size Calculator can help you determine the maximum print quality from your camera's resolution.

Calculating Focus Zones: A Photographer's Practical Example

A photographer is using a 50mm lens at f/2.8 on a full-frame camera (Circle of Confusion: 0.030 mm) to photograph a subject 3 meters away.

Calculate Hyperfocal Distance (H): H = (50^2) / (2.8 × 0.030) + 50 = 2500 / 0.084 + 50 = 29761.90 + 50 = 29811.90 mm, or 29.81 m.
Calculate Near Focus Limit: Near = (29811.90 × 3000) / (29811.90 + (3000 - 50)) = 2730.07 mm, or 2.730 m.
Calculate Far Focus Limit: Far = (29811.90 × 3000) / (29811.90 - (3000 - 50)) = 3329.40 mm, or 3.329 m.
Calculate Depth of Field: DoF = 3.329 m - 2.730 m = 0.599 m.

This example shows that with these settings, the photographer will have a very shallow depth of field, with sharp focus extending from 2.730 meters to 3.329 meters, a total zone of just 0.599 meters.

💡 Precise calculations for depth of field help you capture the perfect shot. To ensure you have enough space to store all your high-resolution images and videos, use a Memory Card Capacity Calculator.

Mastering Selective Focus in Visual Storytelling

Alternative Depth of Field Models and Simplifications

While the traditional depth of field formula, based on the circle of confusion (CoC), provides a highly accurate calculation, photographers often encounter simplified models or alternative approaches, especially in the field. Many online DoF calculators might use a slightly different default CoC value (e.g., 0.029 mm instead of 0.030 mm for full-frame sensors), leading to minor variations in results. Some lens manufacturers also provide lens-specific DoF tables, which are pre-calculated charts based on the lens's optical design, offering quick estimations. Furthermore, many modern cameras and smartphone apps offer real-time DoF previews, which are visual approximations rather than precise calculations. These simplified methods are excellent for quick estimations and on-the-fly adjustments during a shoot, where a precise 0.599-meter DoF might not be necessary. However, for critical work like studio portraiture or macro photography, where exact focus limits are paramount, relying on the full formula with an accurately determined CoC remains the most reliable approach.

Frequently Asked Questions

What is depth of field in photography?

Depth of field (DoF) in photography refers to the range of distance in a photograph that appears acceptably sharp. It is influenced by focal length, aperture, and subject distance. A shallow DoF (e.g., 0.599 m) isolates the subject with a blurred background, common in portraits. A deep DoF keeps more of the scene sharp, often used in landscapes. Understanding DoF is key to creative control over focus.

How does aperture affect depth of field?

Aperture is one of the primary controls for depth of field; a wider aperture (smaller f-number like f/2.8) results in a shallower depth of field, meaning less of the scene is in focus. Conversely, a narrower aperture (larger f-number like f/11) produces a deeper depth of field, keeping more elements from foreground to background acceptably sharp. This allows photographers to control selective focus.

What is hyperfocal distance?

Hyperfocal distance is the closest distance at which a lens can be focused while keeping objects at infinity acceptably sharp. When focused at the hyperfocal distance (e.g., 29.81 m), the depth of field extends from half the hyperfocal distance to infinity, maximizing the zone of sharpness. It's a critical concept for landscape photographers seeking to achieve maximum front-to-back sharpness in their images.

What is the Circle of Confusion in DoF calculations?

The Circle of Confusion (CoC) is the maximum acceptable diameter of a blurred point of light that will still be perceived as sharp by the human eye in a final image. It's a critical input for depth of field calculations, as it defines the boundary between 'sharp' and 'blurry.' Typical CoC values vary by sensor size; for full-frame cameras, 0.030 mm is a common standard, influencing the calculated DoF of 0.599 m.