Topic: How to Choose Common Security Camera Lenses?

Many people find their surveillance coverage incomplete during security projects and keep adding more cameras.In most cases, the real problem is choosing the wrong lens.

Besides resolution, the lens size of a security camera is equally critical.Different lenses produce completely different viewing effects, coverage distances, and fields of view.

In this session, we explain lenses in detail with diagrams for full clarity.

1. How to Select a Camera Lens?

Lens selection is essential for security projects.Let’s start with the focal length selection rules:

The closer the target, the shorter the focal length → wider field of view.

The farther the target, the longer the focal length → narrower field of view.

Use a longer focal length to view distant objects (but narrower view).Use a shorter focal length for a wider view (but shorter viewing distance).

2. Practical Scene Applications

To clearly capture faces, proper lens selection is required.Long-distance face recognition needs a longer focal length.

Application Guide:

Wide-angle lens, over 90° FOV: Elevators, lobbies, etc.Example: 2mm

Over 60° FOV: ~5×5m areasRecommended: 3.6mm, 4mm

Over 50° FOV: 5–10m areasRecommended: 6mm

Over 40° FOV: 10–20m areasRecommended: 8mm

Over 30° FOV: 20–35m areasRecommended: 12mm

Over 20° FOV: 30–50m areasRecommended: 16mm

Telephoto lens, under 20° FOV:Focal lengths from tens to hundreds of mm, mainly for long-distance monitoring.

For longer monitoring distances, use larger telephoto lenses.Some projects use varifocal lenses (adjustable focal length), suitable for long and wide scenes.