An achromatic triplets consist of a low-index crown center element cemented between two identical high-index flint outer elements. These triplets are capable of correcting both axial and laterial chromatic aberration, and their symmetric design provides enhanced performance relative to cemented doublets.
Hastings achromatic triplets are designed to provide an infinite conjugate ratio and are useful for focusing collimated beams and for magnification. In Contrast, Steinheil achromatic triplets are designed to provide a finite conjugate ratio and 1:1 imaging. Paralight Optics offers both Steinheil and Hastings achromatic triplets with an antireflection coating for the 400-700 nm wavelength range, please check the following graph for your references.
AR Coated for the 400 - 700 nm Range (Ravg < 0.5%)
Ideal for Compensation of Lateral and Axial Chromatic Aberrations
Good On-Axis and Off-Axis Performance
Optimized for Infinite Conjugate Ratios
Substrate Material
Crown and Flint Glass Types
Type
Hastings achromatic triplet
Lens Diameter
6 - 25 mm
Lens Diameter Tolerance
+0.00/-0.10 mm
Center Thickness Tolerance
+/- 0.2 mm
Focal Length Tolerance
+/- 2%
Surface Quality (Scratch - Dig)
60 - 40
Surface Irregularity (Peak to Valley)
λ/2 at 633 nm
Centration
< 3 arcmin
Clear Aperture
≥ 90% of Diameter
AR Coating
1/4 wave MgF2 @ 550nm
Design Wavelengths
587.6 nm