Lens Field of View Calculator

Field of View Equation:

\[ FOV = 2 \times \arctan\left(\frac{\text{sensor\_width}}{2 \times \text{focal\_length}}\right) \times \left(\frac{180}{\pi}\right) \]

Field of View (FOV):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Field of View?

Field of View (FOV) is the extent of the observable world that is seen at any given moment through a camera lens. It determines how much of the scene will be captured in the photograph and is influenced by both the focal length of the lens and the size of the camera's sensor.

2. How Does the Calculator Work?

The calculator uses the Field of View equation:

\[ FOV = 2 \times \arctan\left(\frac{\text{sensor\_width}}{2 \times \text{focal\_length}}\right) \times \left(\frac{180}{\pi}\right) \]

Where:

\( sensor\_width \) — Width of the camera sensor (mm)
\( focal\_length \) — Focal length of the lens (mm)
\( \arctan \) — Inverse tangent function
\( \pi \) — Mathematical constant Pi (~3.14159)

Explanation: The equation calculates the angular field of view based on the ratio between the sensor size and the focal length, converting the result from radians to degrees.

3. Importance of Field of View Calculation

Details: Understanding FOV helps photographers choose the right lens for their needs, anticipate how much of a scene will be captured, and compare different camera/lens combinations.

4. Using the Calculator

Tips: Enter the sensor width in millimeters (common full-frame is 36mm, APS-C ~23.6mm, Micro Four Thirds ~17.3mm) and the focal length of your lens in millimeters. Both values must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Why is sensor size important for FOV?
A: The same focal length lens will produce different FOV on different sensor sizes. Smaller sensors effectively "crop" the image, resulting in a narrower FOV.

Q2: What's the difference between horizontal and diagonal FOV?
A: This calculator computes horizontal FOV. Diagonal FOV would use the sensor's diagonal measurement and is typically larger than horizontal FOV.

Q3: How does FOV relate to lens types?
A: Wide-angle lenses have large FOV (>60°), normal lenses ~40-50°, and telephoto lenses have narrow FOV (<30°).

Q4: Can I calculate FOV for zoom lenses?
A: Yes, just input the specific focal length you're using. Zoom lenses have variable FOV depending on their focal length setting.

Q5: Does this work for smartphone cameras?
A: Yes, but you'll need to know the exact sensor width and actual focal length (not the "35mm equivalent" often quoted).