BTW, I was playing with Enderman’s reflector calculator here and noticed something wonky with the standard reflector model.
I tried to model a C8 with SFT25R, which has emitter diameter d=1.7mm, reflector aperture c=40mm, focal length around f=2.78mm, center hole diameter v=4f (always holds for standard parabolic reflectors) = 11.12mm. The calculator gave me a beam half-angle of around 8.7 degrees, which is a full divergence angle of 17.4 degrees, which can’t be right! Could you put the numbers in and double-check me?
My formula, on the other hand, predicts a full divergence angle of 2.2 degrees. I tried measuring my C8 SFT25R (with a known reflector deformity that makes the hotspot hard to define), and got a hotspot diameter of 0.3-0.4m at 8m, which suggests a divergence angle of 2.1-2.9 degrees.