FAQ about Relative Illumination

  • 16 February 2020
  • 4 replies

Userlevel 6
Badge +2

Here we will introduce some FAQs about Relative Illumination in 4 topcis:

* How is Relative Illumination calculated

* Considering Fresnel loss

* Situations that Relative Illumination cannot calculate

* Relative Illumination in systems with FOV > 90 degrees

* Cosine fourth Law


It's suggested to see also this forum post:



4 replies

Userlevel 1
excellent post!!
Userlevel 4
Badge +2

That is great indeed!

Userlevel 7
Badge +3

It should be remembered that cos^4 is not a 'Law', it is simply the result you get with a simple system with no aberration. Distortion is the biggest (but not the only) effect is determining non-cos^4 behavior. If cos^4 was a Law, you woudn't need to compute it based on solid geometry!

Userlevel 4
Badge +2

There is an excellent paper about this from Ronian Sew on LinkedIn.