The Standard specifications of the filters we manufacture are as follows. We also customise our glasses and filters according to your requirements. Please ask our sales representatives for more details.
| Quality Item | Standard | High Precision |
|---|---|---|
| Reference Size | 50 mm x 50 mm | 50 mm x 50 mm |
| Clear Apparture | 90% | 90% |
| Standard Thickness (*) | 2.5 mm | 2.5 mm |
| Surface Roughness | P2 (Rq < 4 nm) | P3 (Rq < 2 nm) |
| Flatness | 3/5(1); λ=632.8 nm | 3/3(1); λ=632.8 nm |
| Wavefront Distortion | 13/3(0.5); λ=632.8 nm | 13/1(0.5); λ=632.8 nm |
| Parallelism | Within 2 minutes | Within 1 minute |
| Bubbles, Inclusions | 1/6 X 0.16 | 1/3 X 0.063 |
| Pits, Sleeks, Scuffs,Scratches, Bubbles and Inclusions on surface | 5/8 X 0.1 L3 X 0.016 (Total length of scratches should not exceed half of the clear aperture dimension which is defined as a circle of 90% in the center of the surface area) | 5/3 X 0.063 L3 X 0.006 (Total length of scratches should not exceed half of the clear aperture dimension which is defined as a circle of 90% in the center of the surface area) |
| Striae | Within specification of transmitted wavefront | Within specification of transmitted wavefront |
| Chip Standard Chamfer 0.3 | Allowed within chamfer E0.25 | Allowed within chamfer E0.25 |
The above standards comply with ISO10110 series.
(*) Excludes thickness of LA/LB/ND filters
V11 and C filters follows HOYA colour filter catalogue. Standard thickness defines to meet optical characteristics according to HOYA filter catalogue.