Field of View Calculator

Sensor Width (mm):

Sensor Height (mm):

Focal Length (mm):

Distance to Subject (meters):

function calculateFOV() { var sensorWidth = parseFloat(document.getElementById("sensorWidth").value); var sensorHeight = parseFloat(document.getElementById("sensorHeight").value); var focalLength = parseFloat(document.getElementById("focalLength").value); var distanceToSubject = parseFloat(document.getElementById("distanceToSubject").value); var resultDiv = document.getElementById("fovResult"); if (isNaN(sensorWidth) || sensorWidth <= 0 || isNaN(sensorHeight) || sensorHeight <= 0 || isNaN(focalLength) || focalLength <= 0 || isNaN(distanceToSubject) || distanceToSubject <= 0) { resultDiv.innerHTML = "Please enter valid positive numbers for all fields."; return; } // Convert focal length and sensor dimensions to the same unit (e.g., meters for consistency with distance) // Or keep them in mm for angular calculation, then convert linear FOV to meters. // Let's keep them in mm for angular, then ensure linear is in meters. // Calculate Horizontal Angular Field of View var horizontalAngularFOV_rad = 2 * Math.atan(sensorWidth / (2 * focalLength)); var horizontalAngularFOV_deg = horizontalAngularFOV_rad * (180 / Math.PI); // Calculate Vertical Angular Field of View var verticalAngularFOV_rad = 2 * Math.atan(sensorHeight / (2 * focalLength)); var verticalAngularFOV_deg = verticalAngularFOV_rad * (180 / Math.PI); // Calculate Horizontal Linear Field of View at the given distance // LFOV = 2 * D * tan(AOV / 2) var horizontalLinearFOV = 2 * distanceToSubject * Math.tan(horizontalAngularFOV_rad / 2); // Calculate Vertical Linear Field of View at the given distance var verticalLinearFOV = 2 * distanceToSubject * Math.tan(verticalAngularFOV_rad / 2); resultDiv.innerHTML = "

Calculated Field of View:

" + "Horizontal Angular FOV: " + horizontalAngularFOV_deg.toFixed(2) + " degrees" + "Vertical Angular FOV: " + verticalAngularFOV_deg.toFixed(2) + " degrees" + "Horizontal Linear FOV: " + horizontalLinearFOV.toFixed(2) + " meters (at " + distanceToSubject.toFixed(1) + "m)" + "Vertical Linear FOV: " + verticalLinearFOV.toFixed(2) + " meters (at " + distanceToSubject.toFixed(1) + "m)"; }

Understanding Field of View (FOV)

The Field of View (FOV) is a critical concept in photography, videography, surveillance, gaming, and many other optical applications. It defines the extent of the observable world that is captured by a camera or seen through an optical device at any given moment.

What is Field of View?

Simply put, FOV is how much of a scene your lens can "see." A wide FOV means you capture a broad area, while a narrow FOV focuses on a smaller, more distant portion of the scene. Understanding and calculating FOV is essential for proper composition, equipment selection, and system design.

Factors Influencing Field of View

Two primary factors determine the field of view:

Focal Length of the Lens: This is the most intuitive factor.
- Shorter Focal Lengths (e.g., 14mm, 24mm): Result in a wider field of view, making objects appear smaller and further away. These are often called wide-angle lenses.
- Longer Focal Lengths (e.g., 100mm, 200mm): Result in a narrower field of view, making objects appear larger and closer. These are known as telephoto lenses.
Sensor Size (or Film Format): The physical dimensions of the camera's image sensor play a significant role.
- Larger Sensors (e.g., Full-Frame 36x24mm): For a given focal length, a larger sensor will capture a wider field of view compared to a smaller sensor.
- Smaller Sensors (e.g., APS-C, Micro Four Thirds): These sensors effectively "crop" the image that a larger sensor would capture with the same lens, resulting in a narrower field of view (often described by a "crop factor").

Angular vs. Linear Field of View

The Field of View can be expressed in two main ways:

Angular Field of View (AOV): This is the angle, typically measured in degrees, from the lens's perspective that covers the scene. It's a fundamental property of the lens-sensor combination and is useful for comparing lenses independently of the subject's distance. For example, a 50mm lens on a full-frame camera has an approximate horizontal AOV of 39.6 degrees.
Linear Field of View (LFOV): This refers to the actual physical width and height (e.g., in meters or feet) of the scene captured at a specific distance from the camera. Linear FOV is crucial for practical applications like planning surveillance camera coverage, determining the area a drone camera can map, or ensuring a subject fits within the frame at a given distance.

How This Calculator Works

Our Field of View Calculator helps you determine both the angular and linear FOV based on your camera's specifications and your desired shooting distance. You simply input:

Sensor Width (mm): The horizontal dimension of your camera's image sensor.
Sensor Height (mm): The vertical dimension of your camera's image sensor.
Focal Length (mm): The focal length of the lens you are using.
Distance to Subject (meters): The distance from your camera to the subject or scene you are observing.

The calculator then provides you with the Horizontal and Vertical Angular FOV in degrees, and the Horizontal and Vertical Linear FOV in meters at your specified distance.

Examples of Field of View

Let's consider a full-frame camera (Sensor Width: 36mm, Sensor Height: 24mm):

Wide-Angle (e.g., 24mm lens):
With a 24mm lens at 10 meters:
- Horizontal Angular FOV: ~73.7 degrees
- Vertical Angular FOV: ~53.1 degrees
- Horizontal Linear FOV: ~14.1 meters
- Vertical Linear FOV: ~9.4 meters
This wide FOV is ideal for landscapes, architecture, or capturing large groups.
Standard (e.g., 50mm lens):
With a 50mm lens at 10 meters:
- Horizontal Angular FOV: ~39.6 degrees
- Vertical Angular FOV: ~27.0 degrees
- Horizontal Linear FOV: ~7.2 meters
- Vertical Linear FOV: ~4.8 meters
Often considered a "normal" perspective, similar to human vision.
Telephoto (e.g., 200mm lens):
With a 200mm lens at 10 meters:
- Horizontal Angular FOV: ~9.9 degrees
- Vertical Angular FOV: ~6.7 degrees
- Horizontal Linear FOV: ~1.7 meters
- Vertical Linear FOV: ~1.1 meters
A narrow FOV, perfect for wildlife, sports, or isolating subjects from a distance.

By using this calculator, you can precisely plan your shots, select the right equipment, and ensure your optical systems meet your specific coverage requirements.