Negative Achromatic Lenses

Negative achromatic lenses(spherical doublets&triplets) are typically used when there is a need to eliminate chromatic aberration. They are commonly inserted between an objective and its image to increase the tube length (as in microscopy) or magnification (as astronomy – a Barlow lens).

Negative achromatic lenses

Glass material: N-BK7 and etc

Desight wavelength: 480nm,546.1nm,643.8nm

Diameter tollerance: +0.0, -0.2mm

Thickness tollerance:  +0.2, -0.2mm

Focal length tollerance: ±2%

Centration: less than 3arc min

Clear aperture: ≥ 85%

Surface quality:60/40,40/20 (scratch&dig)

Surface flatness: λ/4

Negative achromatic lenses(spherical doublets)
Item numberf (mm)Ф (mm)R1 (mm)R2=R3 (mm)R4 (mm)tc1 (mm)t c2 (mm)f b (mm)Lens ALens B