 lens having each of its faces curved outward
Manufacturing Tolerances
| Attribute |
Commercial standard |
Precision standard |
| Material |
BK7 grade A, fine annealed |
BK7 grade A, fine annealed Fused Silica |
| Diameter (Φ) |
+0/-0.5,+/-0.25 |
+0/-0.20,-0.15 |
| Effective Focal Length (f) |
±5%,±3% |
±2%,±1% |
| Irregularity of Fringes |
0.5 |
0.2 |
| Surface Quality |
λ / 2,λ / 4 |
λ / 4,λ /10 |
| Cosmetics (Scratch-dig) |
80-50,60-40 |
20-10,10-5 |
| Center Thickness (t) |
±0.25 |
±0.15,±0.1 |
| Centering Error (arc min) |
3 |
2,1 |
| Clear Aperture |
90% of diameter |
90% of diameter |
| Bevel (mm) |
Fine ground, beveled |
Fine ground, beveled |
| Coating |
See attached coating chapter |
See attached coating chapter |
 All dimensions are in mm unless otherwise specified.
Different material, sizes, tolerance and coating are available upon request.
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