Lens Structure
In optical lens design, multi-layer coating is a key technology widely used in body camera lenses. Its primary goals are to enhance light transmission, reduce surface reflection, and suppress glare and ghosting, thereby delivering clearer and more accurate images.
1. Basic Principle of Coating
Before treatment, the surface of a lens has a significant refractive index mismatch between glass and air, causing approximately 4–8% of incident light to be reflected. This results in:
- Reduced image brightness (low transmission rate)
- Lower contrast
- Unwanted glare and ghosting artifacts
By applying one or more layers of coating materials with specific refractive indices to the lens surface, interference effects between reflected light waves are used to cancel out reflections, significantly improving effective light throughput.
2. Advantages of Multi-layer Coating Technology
| Function | Technical Effect |
|---|---|
| Increased Light Transmission | Boosts effective transmission rate to 95%–98%, yielding brighter, sharper images |
| Reduced Surface Reflection | Minimizes reflective interference on lens surfaces, reducing glare |
| Ghosting Suppression | Diminishes internal lens reflections that cause double images or halos, especially in night scenes with strong light sources |
| Improved Color Fidelity | Reduces stray light impact, ensuring more natural and accurate color reproduction |
3. Common Types of Optical Coatings
| Coating Type | Function | Application Example |
|---|---|---|
| MgF₂ Single-layer Coating | Basic anti-reflection layer | General-purpose consumer camera modules |
| Broadband Multi-layer AR Coating | Anti-reflection across multiple visible wavelengths | High-end body camera lenses |
| IR-Cut Filter | Blocks infrared light to enhance color accuracy during daytime | Dual-mode lenses with day/night auto-switching |
| Oleophobic / Anti-fingerprint Coating | Resists smudges and oil, easier to clean | Increases lens durability and user convenience |
Shelleyes body cameras adopt advanced multi-coating lens technologies to ensure high transmission rates, minimal artifacts, and optimal imaging performance even under challenging lighting conditions such as direct sunlight or nighttime glare. This meticulous design approach supports accurate evidence recording and consistent image quality in all field environments.