What Is Field of View (FOV)?
This camera lens FOV guide covers formulas, examples, and tables to help you find the right camera lens FOV for any project.
Field of View (FOV) is the observable area a camera can capture. It’s typically measured in degrees and expressed as:
- Diagonal FOV (most common)
- Horizontal FOV
- Vertical FOV
Choosing the right FOV determines whether your camera sees a wide area (like a whole room) or zooms in on a specific spot (like a doorway).
The FOV Formula
The basic formula for calculating horizontal FOV:
FOV = 2 × arctan (sensor width / 2 × focal length)
Or simplified:
FOV = 2 × arctan (d / 2f)
Where:
- d = sensor size (width)
- f = focal length (mm)
Common Sensor Sizes (2.9” type refers to optical format)
| Sensor Type |
Width (mm) |
Height (mm) |
| 1/4″ |
3.6 |
2.7 |
| 1/3″ |
4.8 |
3.6 |
| 2.9“ |
4.8 |
3.6 |
| 2.7“ |
5.4 |
4.0 |
| 2.5“ |
5.8 |
4.3 |
| 1/2″ |
6.4 |
4.8 |
Camera Lens FOV Calculation Examples
Example 1: 2.85mm lens + 2.9” sensor
- Focal length: 2.85mm
- Sensor width: 4.8mm
Horizontal FOV = 2 × arctan(4.8 / 2×2.85)
= 2 × arctan(0.842) ≈ 80°
Diagonal FOV ≈ 100°
Example 2: 1.8mm lens + 2.9” sensor
- Focal length: 1.8mm
- Sensor width: 4.8mm
Horizontal FOV = 2 × arctan(4.8 / 2×1.8)
= 2 × arctan(1.33) ≈ 107°
Diagonal FOV ≈ 130°
Example 3: 3.6mm lens + 1/3″ sensor
- Focal length: 3.6mm
- Sensor width: 4.8mm
Horizontal FOV = 2 × arctan(4.8 / 2×3.6)
= 2 × arctan(0.667) ≈ 67°
Diagonal FOV ≈ 85°
Camera Lens FOV Quick Reference Table
2.9” Sensor (4.8mm × 3.6mm)
| Focal Length |
Horizontal FOV |
Diagonal FOV |
| 1.4mm |
120° |
150° |
| 1.8mm |
107° |
130° |
| 2.3mm |
95° |
115° |
| 2.85mm |
80° |
100° |
| 3.6mm |
67° |
85° |
| 6mm |
45° |
55° |
1/4″ Sensor (3.6mm × 2.7mm)
| Focal Length |
Horizontal FOV |
Diagonal FOV |
| 1.4mm |
100° |
120° |
| 1.8mm |
90° |
110° |
| 2.3mm |
78° |
95° |
| 2.85mm |
65° |
80° |
| 3.6mm |
53° |
65° |
How to Choose the Right Camera Lens FOV
| Application |
Recommended Horizontal FOV |
| Doorbell camera |
150° – 180° |
| Home indoor |
110° – 130° |
| Small shop |
90° – 110° |
| Office corridor |
60° – 80° |
| Parking lot |
70° – 100° |
| License plate capture |
30° – 50° |
Why Sensor Size Matters
The same focal length lens gives different FOV on different sensor sizes:
| Lens |
On 1/4″ Sensor |
On 2.9” Sensor |
| 2.85mm |
65° |
80° |
| 3.6mm |
53° |
67° |
Tip: A lens designed for a 1/4″ sensor typically won’t work well on a 2.9” sensor (image quality issues). Always match your lens to your sensor size.
Need Help Choosing?
Use this simple approach:
- Measure your target distance (how far is the camera from the subject?)
- Define the width you need to cover (how wide is the area?)
- Calculate required FOV using the formula above
- Match to lens focal length using our reference tables
Or simply contact LYX LENS — our engineers can recommend the right M12 lens for your specific sensor and FOV requirement.
Published: October 2026
Reading time: 6 min
Target keywords: camera lens FOV calculation, field of view formula, how to calculate camera angle, M12 lens selection
