These are often used for diverging light and image reduction, as well as increasing system focal lengths and collimating converging light beams. Bi-concave lenses are commonly utilized with other lenses in order to reduce the focal lengths of optical systems.
Specifications
| Diameter | Surface
Quality | Diameter Tolerance
| Center Thickness Tolerance
| Edge Thickness Tolerance | Centering Tolerance
|
| | | | | | |
| 3.00 - 5.00 | 40-20 | +0/-0.05 | +/-0.2 | Reference | 3-5arc mins |
| 5.01 - 25.40 | 40-20 | +0/-0.1 | +/-0.2 | Reference | 3-5arc mins |
| 25.41 - 40.00 | 60-40 | +0/-0.1 | +/-0.2 | Reference | 3-5arc mins |
| 40.01 - 75.00 | 80-50 | +0/-0.1 | +/-0.2 | Reference | 3-5arc mins |
