Optical Lens Assemblies Optical Assemblies This lens is a fast (f/1.2) wide angle (100°) SWIR lens to cover the range of 600-1700nm Low F--Ã? distortion and high transparency. This lens is excellent for spectral analysis by changing filters and compact size . The lens can be modified for several detectors and mechanical housing . Mount adaptor . This lens is a fast (f/1.2) wide angle (100°) SWIR lens to cover the range of 600-1700nm Low F--Ã? distortion and high transparency. This lens is excellent for spectral analysis by changing filters and compact size . The lens can be modified for several detectors and mechanical housing . C-Mount adaptor .