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.
|Centration||3 arc minutes|
|Surface Figure||1/4 wave @632.8nm|
|Surface Quality||10-5 scratch and dig|
|Coating||None, AR, AL...|