As the eyepiece and creates a collimated beam for the observer's eye.
A lens with one plane surface and one concave surface .
As the eyepiece and creates a collimated beam for the observer's eye
Manufacturing Tolerances of Plano-Concave Lens
| Material |
BK7 grade A, fine annealed |
UV Fused Silica |
| Sizes |
Φ3-600mm |
Φ3-40mm |
| Design Wavelength |
546.1nm |
546.1nm |
| Focal Length (f') |
±2% |
±2% |
| Irregularity of Fringes |
0.2-0.5 |
0.2-0.5 |
| Diameter (θ) Tolerance |
< +0.00/-0.20mm |
< +0.00/-0.20mm |
| Surface Flatness |
< λ / 4, < λ/10 @ 633 nm |
< λ / 4, < λ/10 @ 633 |
| Surface Quality |
60-40, 20-10 , 10-5 scratch-dig |
nm20-10 scratch-dig |
| Center Thickness (Tc) |
<±0.1mm |
<±0.1mmMgF2 AR |
| Coating |
MgF2 AR Coated |
Coated |
| Centration Error |
≤3 arc min |
≤3 arc min |
| Clear Aperture |
90% of diameter |
90% of diameter |
| Bevel: |
0.25mmX45° |
0.25mmX45° |
All dimensions are in mm unless otherwise specified.
Different material, sizes, tolerance and coating are available upon request.
