1. What is Focal Length?

Focal length determines the angle of view and magnification of a security camera. It affects how much of the scene will be visible and how large objects will appear in the image.

2. How Does the Calculator Work?

The calculator uses the focal length formula:

Where:

• \( Sensor\ Size \) — Size of the camera sensor (mm)
• \( Working\ Distance \) — Distance from camera to subject (mm)
• \( Field\ of\ View \) — Width of area to be monitored (mm)

Explanation: The formula calculates the ideal lens focal length based on your specific camera setup requirements.

3. Importance of Focal Length Calculation

Details: Choosing the correct focal length is crucial for security cameras to ensure proper coverage of the area you want to monitor without unnecessary blind spots or wasted coverage.

4. Using the Calculator

Tips: Enter sensor size in millimeters (common sizes: 1/3" = 4.8mm, 1/2.7" = 5.4mm), working distance in millimeters, and desired field of view in millimeters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical focal length for security cameras?
A: Common focal lengths range from 2.8mm (wide angle) to 12mm (telephoto), with 3.6mm being standard for many applications.

Q2: How does focal length affect the image?
A: Shorter focal lengths provide wider views but less detail at distance, while longer focal lengths provide narrower views with more detail at distance.

Q3: What if I need to calculate in inches?
A: Convert all measurements to millimeters (1 inch = 25.4mm) for accurate results with this calculator.

Q4: Should I consider varifocal lenses?
A: Varifocal lenses (e.g., 2.8-12mm) offer flexibility but are more expensive than fixed focal length lenses.

Q5: How does sensor size affect the calculation?
A: Larger sensors require longer focal lengths to achieve the same field of view as smaller sensors.