Lighting Light Penitration Question

[Heavily Medicated]

I have read that different light sources have better or worse light penitration. What is it that actually causes this, if it is true. Would the same number of lumens emitted from different lights, say T5 vs LED, both penetrate the same distance? Does the spectrum have anything to do with it? I would think that a lumen is a lumen. Anybody know about this stuff?

 

[Heavily Medicated]

I guess not.

 

[ukfreak]

hope this helps some

[video=youtube;hx2ZWw00c9Q]https://www.youtube.com/watch?v=hx2ZWw00c9Q[/video]

It's time to learn the Inverse Square Law about lumens and light penetration depth.

1 foot from light source = 100% illumination and LUMENS
2 feet from light source = 1/4 as bright
3 feet from light source = 1/9 as bright
4 feet from light source = 1/16 as bright

The Inverse Square Law ( ISL ), basically states that your plant will receive 100% lumens IF it's within 1 foot of the light source.
For every ADDITIONAL 1 foot of distance AWAY from the light source, lumens and therefore canopy penetration diminishes GREATLY !!!


Please keep in mind that those utilizing a glass lens in an air-cooled hood/tube of ANY kind are NOT getting 100% lumens because of the glass lens.

For the purpose of simple division, we'll use a light with an output of 100,000 lumens, which is roughly 10,000 MORE lumens that the average 600w HPS and roughly 40,000 lumens LESS than the average 1,000w HPS.

1 foot within light = 100,000 lumes (100%)
1 - 2 feet from light = 25,000 lumens (250w HPS roughly within 1 foot)
2 - 3 feet from light = 11,111 lumens (125W CFL roughly but less than 150w HPS within 1 foot)
3 - 4 feet from light = 6,250 lumens (250w HPS @ 1- 2 feet from light)

So as you can see, the drop in lumens and how much light penetrates your gardens canopy drops significantly with every 1 foot of distance away from the light source.
At 2 feet away, my 400w Hortilux (55,000 lumens) pretty much hits like a 150w HPS, and anything below that gets trimmed off (popcorn buds).