Ever since I first heard of spherical harmonics as an approximation in computer graphics, I have felt that the way they are explained is too complicated. Sometimes the explanations assume a bunch of math knowledge that isn’t really necessary, and they tend to be very abstract. Other times they show something complex and through a lot of effort end up simplifying them to something usable. In addition to making it harder to learn, I think those approaches to SH can lead to misapplication. SH introductions often have discussion about certain SH artifacts (ringing and negative values), but ignore another class of common issues.