CCTV Lens Calculator
Calculate the required focal length for proper pixel density in license plate and face recognition
What do you want to do?
Camera Settings
Target Settings
Lens Settings
Quick Scenario Templates
Click to apply common surveillance scenario settings
Indoor Scenarios
Outdoor Scenarios
Special Requirements
Calculation Results
Field of View Diagram
Focal Length vs FOV Chart
Pixel Density Standards (IEC 62676-4)
| Use Case | PPM | Description |
|---|---|---|
| Detection | 25+ | Detect human presence |
| Observation | 62+ | Identify clothing characteristics |
| Recognition | 125+ | Recognize familiar people |
| Identification | 250+ | Confirm identity |
| License Plate | 330+ | Read license plate characters |
About CCTV Lens Calculator
Read more
This calculator helps you determine the required lens focal length for CCTV cameras based on monitoring distance and target size. Whether for license plate recognition, face recognition, or general surveillance, find the optimal lens specifications.
Calculation Formulas
Focal Length: f = (Distance × Sensor Width) / Target Width
Field of View: FOV = 2 × arctan(Sensor Width / (2 × Focal Length))
Pixel Density: PPM = Resolution / View Width
How to Use
- Select calculation mode: "Help me pick a lens" or "I already have a lens"
- Choose your camera sensor size (commonly 1/2.8" or 1/3")
- Enter target distance and width (or known focal length)
- Review recommended focal length, FOV, and pixel density assessment
Selection Tips
- License plate recognition needs PPM ≥ 250 (ideally 330+); facial identification needs PPM ≥ 250
- Indoor surveillance typically uses 2.8-4mm wide-angle lenses
- Parking lot entrances should use 6-12mm medium focal length lenses
- Long-range surveillance (50m+) requires 25mm+ telephoto lenses
Frequently Asked Questions
Q: What is sensor size?
A: Sensor size affects the camera's field of view. With the same focal length, larger sensors provide wider coverage. Common formats include 1/4", 1/3", 1/2.8", etc.
Q: What is PPM?
A: PPM (Pixels Per Meter) measures pixel density, indicating how many pixels cover one meter. Higher PPM means clearer image details, better suited for identification tasks.
Q: How to choose the right lens?
A: Choose based on monitoring distance and recognition requirements. Use short focal lengths (2.8-6mm) for close-range wide-angle monitoring, long focal lengths (12mm+) for distant license plate recognition.
Formula Sources
This calculator uses standard optical formulas, referencing IEC 62676-4 security standards and IPVM pixel density guidelines.
