UHHH ithinki got it figured out
You do need the 4pi thing because of the sperical area we are describing. OK here we go again. I am going to relabel everything and you can disregard my previous post.
E=footcandles It is what you measure with the light meter.
I=lumens What the manufacturer gives you on the box.
A=area=4pi(d^2) with d in feet. This is where i went wrong.
OK so E=I/4pi(d^2)
E=19000 lumens at the highest reading.
d=2.5in/12in/ft=.208333ft
I=19000*4pi(.208333^2)=10362 lumens
There we go. Right on, if not a little high. Which im kinda glad about because the only reason i started researching lighting for indoors was because i want to start an indoor grow and im looking for the best light.
BUT we are only halfway there. We have more that we need to find out about this light and others.
1. You need to go back to the store and get the measurements for other CFL lamps to compare with.
2. We need to find out what spectrum all of this light is in. If it is all in the wrong spectrum than you wont have really dense bud. Also you have to count bud per lumen per day as it would not be fair to take 2 months of vegging and 3 months of flowering and compare it dead on with MH/HPS grows that were done at 1mo veg and 2mo flower.
3. We need to figure out how it actually compares to MH/HPS in actual lumens presented to the plant. I know heat and all that. So iwill try to work out a fair calculation to distances for MH/HPS setups from the plant at different distances and will post them when i get done. I will use standard lumen readings from reputable manufacturers such as philips.
I think we are finally getting somewhere
Also if anyone sees a shortcoming in the calculations let me know |