Jack07013
03/22/2010, 02:16 PM
is there a way to calculate PAR for different focal lenses 40,60,80, 120 for the same LED bulb knowing value for one focal lense at the same distance?
For example - CREE -XP E - without focal lense (interanl viewing angel only) gives out PAR XXX at such distance ZZZ. is there way to calculate PAR if you would put on 40 degree focal lense on the same LED bulb, at the same distance?
For example - CREE -XP E - without focal lense (interanl viewing angel only) gives out PAR XXX at such distance ZZZ. is there way to calculate PAR if you would put on 40 degree focal lense on the same LED bulb, at the same distance?