Selection Principles for Night Vision Focus Lens

1. Spectral Response & Infrared Sensitivity

   The lens must have high transmittance in the near-infrared band (typically 850nm or 940nm) to ensure sufficient light intake and clear imaging in low-light or night environments.
2. Aperture Value

   A large aperture (small F-number, such as F1.2, F1.4) is preferred for night vision applications, as it improves light-gathering capability, reduces image noise, and enhances brightness in dark conditions.
3. Focal Length & Field of View

   Select the focal length based on monitoring distance and viewing range:

   • Long focal length for long-distance observation

   • Short focal length for wide-area coverage
4. Resolution & Image Clarity

   The lens should match the sensor resolution and provide high sharpness, avoiding blur, ghosting, or edge distortion, especially under infrared illumination.
5. Focus Mechanism

   Choose fixed-focus, manual-focus, or auto-focus lenses according to application scenarios:

   • Fixed-focus for stable, long-term monitoring

   • Adjustable focus for variable working distances
6. Environmental Reliability

   For outdoor or industrial use, the lens must be resistant to high/low temperatures, dust, moisture, and vibration to maintain stable performance.
7. Structural Compatibility

   Ensure compatibility with image sensors, mounting interfaces (such as M12, C/CS mount), and mechanical space constraints for proper assembly.