Dimmable LED for veg

[GreenGrowth]

I've been doing some research into using the dimmer on my new LED light and have come to the conclusion that at a certain height i.e. 450mm (18in) i should run at around 50% to obtain the correct light umol/s of par and ppfd. In theory if i have it at 100% and a greater distance away i should achieve the same results. Has anyone some clarification on these figures

 

[StoneOtter]

Hi GreenGrowth, something like that. I'm not sure it's linear. Like if at 18 inches you get 600 ppfd of par will I get 300 at 36 inches, or will it be a number different? I guess that's the question huh? I'm having luck with an ap called Photone. It uses your cell phone to measure light. For $5.00 to unlock the proper type light to be measured I find it helpful. Some folks find it off but I've had good readings with it. Good enough to grow. I bet it would help answer your question if you used it for some testing.

 

[bluter]

I've been doing some research into using the dimmer on my new LED light and have come to the conclusion that at a certain height i.e. 450mm (18in) i should run at around 50% to obtain the correct light umol/s of par and ppfd. In theory if i have it at 100% and a greater distance away i should achieve the same results. Has anyone some clarification on these figures

you have observed what is called the law of inverse square. it applies directly to lighting and is very relevant.