CREE and Citizen Electric spectrum help

Hi guys,

I started researching DIY LED lighting a few days ago, and something has been bugging me. All of the spectrum graphs published on the data sheets for popular CREE and Citizen Electric COBs have a huge cut around 480nm. However, part of my research tells me that is the range of blue that plants like to create chlorophyll. Even the horticulture specific COBs CE do have this cut. Please can someone explain this away for me?

Thanks.

I'm not an expert in this but I think it's cause 480 is where it starts to go from blue to green. In my basic understanding, blue goes from 450-480 and green is like 490-530 which is where you see the big dip. 3000k temperature COBs will have less of a dip there than 5000k cobs, which have a bigger blue spike and then drop off considerably.

gibblybibbly said:

Hi guys,

I started researching DIY LED lighting a few days ago, and something has been bugging me. All of the spectrum graphs published on the data sheets for popular CREE and Citizen Electric COBs have a huge cut around 480nm. However, part of my research tells me that is the range of blue that plants like to create chlorophyll. Even the horticulture specific COBs CE do have this cut. Please can someone explain this away for me?

Thanks.

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Hi! People use 3000/3500°k for bloom and some even 4000°k and for pure vegg you can use 4000/5000°k 3500k and 4000k for both! There is 6500°k COB but it is only usefull to keep short and bushy mother plants! Or if you plan on growing a real landrace sativa it help a lot with stretch who can be X5
Have a lifted one

all phosphor based cobs are "pumped" by blue mono leds in the 440-460 range. the blue "peak" you see on spectra is this shining thru the phosphor

the big wide bump from 500-700 nm is the phosphor converting the blue into orange/red light. this is why chips (when they are powered off) have different colors of phosphor

for a given CRI, a lower color temp chip like a 2700k will have a phosphor that looks a lot more orange than a chip like a 6500k which is more yellow looking.

90 cri vs 80 cri use different phosphor compositions you can see the red peak is shifted

for all of the chips, together the blue peak and reddish bump make an artificial white spectrum that is actually really great for plants. some 480-530 is useful but its not the most absorbable or photosynthetically active range. the blue and red peaks on phosphor white LEDs correspond reasonably well with the plants ideal ranges