|Effective Focal Length EFL(mm)||-70.00±1%||Back Focal Length BFL(mm)||-71.78|
|Coating||400-700nm AR||Surface Quality(S/D)||40/20|
|Irregularity@632.8nm||λ/4||Centration Error(arc min)||≤2|
|Curvature Radius R1||-36.18||Clear Aperture||90%|
Concave lenses, are a simple lens with one spherical face and one flat plano face, it has a negative focal length, allowing the part to increase the divergence of convergent light. Concave lenses can be used to balance out the spherical aberrations caused by other lenses. Concave lenses have a broad range of applications including, focusing and control of laser beams, moderate quality imaging and other optical instruments.
Hangzhou Shalom EO stock a series of N-BK7 plano-concave lenses with variety of diameter, focal length and coatings, and the custom lens with other specifications are also available upon request.