How about do some testing with decent leds,instead of apollos and crappy chinese epistars before you start talking about how you cant grow photos with COBs.
sure make my dad cancer go into remission then i can redirect funds back into experiments other then paying for the bills for the house and hospital
when i started testing Cobs were the babies back in the day they were talking about Plasma lights (god awlful thought super heated plamsa in a contain area run by stoners)
u want to talk LED
1 i have already given the Par info (site has the deep math if u want for convertions)
2 he has to make a choice on what likes to see the specs about it ...to keep telling him info on it
3 lens degree for him is fairly simple 90 for the depth with the shallow area he has but enough to get reflection power off the walls to increase the par on the edge of his area
4 if he wants i can tell him how to get the light cheaper then most of u ppl even thought of .......contact the markers by pass retail pay import taxes and shipping comes out less then retail by far
but he has a small area a 600w system would be to strong for him as he needs 2 lights minial to cover the 8 foot area