Hello all. I received a SQ-420 from someone who did not know how to use it and quite frankly I am ignorant as well. I have it mounted on a selfie stick and have the software on a laptop. I am totally ignorant and my head spins when I look at mathematical formulas. Could someone explain the correction factor in terms a person who can only do basic math (not even algebra) can understand? I'm trying to get par measurements under radion xr15 pro gen 4 lights. How do I set up the software and what math formula is needed to get a somewhat accurate reading of the par under my lights. Sorry to be long winded and not to bright but my education stopped when I quit school in the 9th grade to go to work full time 46 years ago. And yes I'm still working full time. dang I should have stayed in school :-(