Many of our customers have questions about the terms and methods used by an optical engineer. Our hope is that the information provided on these pages will help you to understand how to interpret some of the results we provide. If you’re interested in optical testing, start here, optical design, go here, or if optics is new to you, it would be a good idea to start with the basic optical terms. After that, feel free to jump in anywhere.

Lens Design


  • Etendue
  • Pupils and Stops
  • Critical and Kohler Illumination
  • Radiometric and Photometric Terms

Optical Scattering