Lens Element Count (Glass / Plastic)
Lens element count refers to the number of individual optical components used inside the lens module, typically composed of multiple pieces of optical glass or plastic lenses. The combination of materials and element layers significantly affects image quality, especially in terms of sharpness, chromatic dispersion control, and durability.
1. Types of Materials
Optical Glass Lenses
- Advantages: High light transmittance, excellent thermal stability, and strong scratch resistance—ideal for high-precision imaging.
- Disadvantages: Higher cost, more difficult manufacturing, and slightly heavier.
Optical Plastic Lenses
- Advantages: Lightweight, easier to manufacture, lower cost, and flexible for designing aspherical shapes.
- Disadvantages: Prone to aging over time, sensitive to thermal expansion and contraction, slightly lower light transmittance than glass.
Note: Many body cameras today adopt hybrid lens assemblies (glass + plastic) to balance imaging performance and cost efficiency.
2. Advantages of Multi-Element Lens Design
Modern body cameras typically use 5P, 6P, or 7P lens structures, where P stands for “pieces” of optical elements. Multi-element designs offer the following benefits:
- Enhanced Image Sharpness
Multi-element lenses correct spherical aberration, coma, and distortion, maintaining high resolution from center to edge. - Chromatic Aberration Control
Glass and plastic have different dispersion coefficients. A well-designed combination can compensate for light across wavelengths, reducing chromatic aberration and minimizing color fringing (e.g., purple edges around objects). - Improved Night Vision Performance
High-quality lens stacks combined with IR-cut filters or broadband optics help maintain clarity and color fidelity under low-light or night-time conditions.
3. Examples of Material and Layer Combinations
| Lens Structure | Description | Application Level |
|---|---|---|
| 4P Plastic | All-plastic construction, low cost and lightweight | Entry-level body cameras |
| 5G + 1P | 5 glass lenses + 1 plastic lens | Mainstream models with HD output |
| 6G + 1 IR | 6 glass lenses + 1 IR filter | High-end models with full-color day/night imaging |
4. Application Recommendations
For high-temperature or harsh environments:
Prioritize lens assemblies with a higher glass content to improve durability and operational stability.
For high image quality requirements (e.g., facial or license plate recognition):
Choose lenses with 6 or more elements, including glass components.
For lightweight demands (e.g., helmet-mounted body cameras):
Opt for lens modules with a higher ratio of plastic elements.