Description:
Collimating lenses are optical lenses that make parallel the light beams that enter your spectrometer setup. These lenses allow users to control the field of view, collection efficiency and spatial resolution of their setup, and to configure illumination and collection angles for sampling. 
Optosky collimating lenses can be attached to the spectrometer, coupled to optical fibers, or integrated into sampling accessories. Most lenses have an inner barrel threaded for SMA 905 connectors. The inner barrel slides relative to the lens fixture for adjusting the focus; a setscrew secures the barrel.
Feature:

• Versatile – lenses optimized for the UV-Visible (185-2500 nm) or Visible-NIR (350-2500 nm)
• Multiple options -- single, achromatic and long focal length versions available
• Rugged – stainless steel barrel with black oxide finish
• Fiber optic – couple to optical fibers or spectrometers
• Adjustable – position lenses for converging to diverging FOV (~25°)