KrakenPeppers said:
Light drop off is quiet remarkable and not so noticeable to the eye... A supple test is to hold up a pepper leaf to the fluro real close then move it away you will see the huge difference in light penetration.
"Light intensity varies as the inverse square of the distance."
... In commonsense plainspeak, if you double the distance from the lightbulb, you don't get half the light intensity, you only get a quarter of it. At 3 times the distance, only 1/9th the intensity. Ten times the distance yields only 1% of the initial light intensity.
That cuts both ways... half the distance yields 4X the intensity, and 1/3 hits the leaves with 9X the intensity. That's the reason why there's so little difference between optimal distance and leaf burn, and why conscientious -- but inexperienced -- growers often give less than optimal light to their plants: at optimal levels, the plants grow much quicker... thus getting too close to the light in a relatively short time. The leaves can burn within days of moving the light to an optimal distance because -- within a couple of days -- the growing tops get too close. Then they get 'sunburnt'
The grower then overcompensates by always keeping the lights a little too far, and the light intensity too low. The plant stretches to compensate... and gets burnt again.
I did this for the longest time. The fact that some plants grow faster than others makes this problem even more, uhhh, interesting. No matter how conscientious you are, it's still entirely possible to get some stretched plants and some scorched ones -- both problems occuring at the same time!!
A wide/broad array of multiple light sources (ie.: t5s, LEDs) and/or a well-designed reflector (one that distributes the light more evenly, with lesser/fewer "hot spots" of excess light intensity) can really help a lot.
I think the lens-like nature of some makes of LEDs should help too, sinces they offset radiant light's normal tendency to disperse, but i've never worked with them.
Hope this helps.
