Comparison of multispectral zinc sulphide and standard zinc sulphide
Standard Zinc Sulfide: suitable for mid-infrared and far-infrared wavelengths, lower cost, but low transmittance in the visible wavelengths.
Multispectral zinc sulfide: suitable for visible, near-infrared, mid-infrared and far-infrared wavelengths, with excellent transmission performance in the broadband, but at a higher cost.

Highly Recommended Infrared Lenses from Yutai Optics:
Optical Infrared Lenses
Infrared Silicon Lens
Infrared ZnSe Lens
Infrared CaF2 Lens
Infrared MgF2 Lens
Infrared BaF2 Lens
Infrared LiF Lens
Infrared Germanium Lens
Infrared Multispectral ZnS Lens