A triplet lens is cemented by one piece of crown glass with low refractive index and two pieces of flint glass with high refractive index, normally the cemented lens can eliminate spherical chromatic aberration of axial direction. Because the design of these lenses are complete symmetrical, so they can be used by changing-over. The commonly used materials include crown glass and flint glass.
Triplet Achromatic Lenses are designed for 1:1 conjugate ratios and utilize symmetry to correct for aberrations. They are made from a low index center element cemented between two identical high index outer elements. Each lens is edged down to f-numbers with reasonable aberration correction at increased fields. Some medical instrument will use micro triplet lenses.
Materials:Three kinds of optical glasses
Diameter Tolerance:+/-0.1 mm
Centring Error<3 Arc minutes
Coating: Specified by customers