Although many years ago I was pretty good at physics, I have not been able to get my arms around all the light terms. But in particular I'm confused by some of the Source Four photometrics. I've attached a table. I don't understand why in one case the Candela multiplying factor, Lumen MF, and ratio of Initial Lumens are all the same, but in most cases they are not. Ultimately I just want to make sure I am calculating the illuminance correctly.