Negative Achromats are corrected for color and on-axis spherical aberration. They are used mostly to extend focal lengths along with positive achromatic systems or CCD lenses.
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 |
