Oded Erell writes:
I developed an advanced emission shader for Cycles that produces IES style lighting for architectural interiors/exteriors.
The shader has a built-in library of 20 real-world spotlight beam designs, that can be easily switched between without loading external files,
And also allows tweaking features like the light beam focus and chromatic dispersion effect, that are not available in regular IES lighting.
https://vimeo.com/265995138