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2.8mm vs 4mm camera lenses

On the same sensor, a shorter focal length generally gives a wider view. A longer focal length generally shows a narrower area. Sensor dimensions and lens distortion also matter.

1. Use the manufacturer’s horizontal field-of-view specification when available. Focal length alone does not define the coverage angle.
2. CCTV Mapper’s lens presets are approximate simulations, not a database of verified camera optics. You can adjust the map cone for your intended coverage.
3. Compare coverage width at a chosen distance with the FOV calculator. It assumes a flat plane and an angle below 180 degrees.
4. Verify useful image detail at the target, including lighting and compression. A colored cone does not certify recognition or identification.

Planning guidance, not installation certification. Follow the device manufacturer’s instructions and validate the finished system.

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CCTV Mapper product guide · Updated October 16, 2026