This type of lens is a combination of two single lenses with different refractive indices glued together, which has the characteristics of short focal length, large magnification, and good imaging quality. It has effectively corrected paraxial aberrations such as spherical aberration, coma aberration, and chromatic aberration, and has been widely used in astronomical telescopes and cameras.

Material: CaF2, MgF2, quartz, K9, etc.

Design wavelength：587.6nm

Central Thickness Tolerance: ± 0.1mm

Dimensional Tolerance: ± 0.1mm

Focal Length Tolerance: ± 1%

Surface Quality: 60/40

Surface Accuracy: λ/10~2λ