Newport MKS Negative Achromatic Doublet Lens, Visible, 12.5 mm, -20 mm EFL, 400-700 nm NAC013

The NAC013 Visible Negative Achromatic Doublet Lens is a 400 to 700 nm antireflection coated, 12.5 mm diameter, N-BAF10 and N-SF10 precision achromatic doublet lens with an effective focal length of -20 mm. The negative achromats are commonly used for expanding the beam diameter, increasing focal length and increasing the magnifications of an optical system. This negative achromat is computer designed to effectively minimize spherical aberration and coma when operating at infinite conjugate ratio. Unlike singlet lenses, this results in a constant focal length independent of aperture and far better off-axis performance. Achromats are superior to singlet lenses for monochromatic applications at any visible wavelength.