Triplets specifically designed for 1:1 conjugate ratios are ideal for use in relay systems. By the principle of symmetry aberrations are corrected automatically. They are made from a low index center element cemented between two identical high index outer elements. In addition, outer surfaces of the lens are coated with anti-reflection layers to increase transmittance of the lens according to the wave length of light under which the lens to to be used.
| Specifications | |
| Material | Optical glass |
| Dimension Tolerance | +/-0.05mm |
| Centration | 3 arc minutes |
| Clear Aperture | >95% |
| Surface Figure | 1/4 wave @632.8nm |
| Surface Quality | 10-5 scratch and dig |
| Bevel | 0.1mmX45 degree |
| Coating | None, AR, AL... |
