frica
Well-Known Member
The Decor series/high CRI Crees have a very sexy light spectrum output.
Very high in the red and also a nice peak at blue.
Photosynthesis Under Solid State Light. Setting the Standards .
- Thread starter stardustsailor
- Start date
Very high in the red and also a nice peak at blue.
Greengenes707
Well-Known Member
For everyone interested in higher CRI who has not been around a while...or who may have forgot. Here is some more brilliant sds analysis on the subject...
https://www.rollitup.org/t/cxa-3000k-80-vs-93-cri-an-estimation.833171/
The cxb's high cri top bins close the gap vs the cxa and vero, but they are not available to even play around with.
https://www.rollitup.org/t/cxa-3000k-80-vs-93-cri-an-estimation.833171/
The cxb's high cri top bins close the gap vs the cxa and vero, but they are not available to even play around with.
coolbreez1
Well-Known Member
I was not meaning to imply that the high CRI unto its self would make it a better grow light, the CRI has nothing to do with my statement beyond indicating which light I was referring to. I was just looking at the fact that it has much more red in the higher end of the spectrum and more magenta, and that without doing any of the math it looks as if it would best match the PAR we are looking to replicate.
alesh
Well-Known Member
I'm pretty sure that a lot of you have seen this chart many times.
Tikhomirov, et al., 1991
It's an interesting one, however, applies to 15-day-old radish canopies.
My question - is there a similar chart for cannabis and/or a plant more similar to cannabis than a radish? Such a chart would make it possible to determine maximum and most efficient point of intensity for each spectrum.
Tikhomirov, et al., 1991
It's an interesting one, however, applies to 15-day-old radish canopies.
My question - is there a similar chart for cannabis and/or a plant more similar to cannabis than a radish? Such a chart would make it possible to determine maximum and most efficient point of intensity for each spectrum.
ttystikk
Well-Known Member
Why not? I'm interested in your logic here.
Abiqua
Well-Known Member
HPS is something like 22 CRi.....
Color rendering index is another "anthro" light source, how well a light renders to the human eye....but because of its classification, can be kind of broken down into segments and use to guesstimate [technically]....but not many mess around with it....
although those top bin CXB 3590's may change that in the future, since the output doesn't seem to be throttled in the 600-700nm as with other high CRI models, as based on some of the predictions from the guru's around here.....
The overall gist so far is that high CRI is really just a bottleneck for photon outpout [decreasing] and the trade off with "more" of the red and deep red frequency's available to achieve "high" Cri, but at a lower photo output trade-off ....again newer diode tech, may change that.....
ttystikk
Well-Known Member
CRI= Color Rendering Index. Indexed against what? The sun. That's not 'rendered to a human eye'. You got it mixed up with lumens.
HPS CRI = 22, proof enough that if you give plants enough shit, they'll eat it. Good spectrum is no substitute for adequate irradiance, however. Turns out the ladies like both.
Abiqua
Well-Known Member
Again, its an an anthro light measurement....it measures how well light is reproduced according to a natural source [Sun]...that WE see...
ttystikk
Well-Known Member
No, the index is measured as instruments see the Sun's mix of spectra and the index quantifies how well the artificial light source renders it. Human perception is not a part of CRI determination.
I'm not saying that a CRI of 100 is the be-all, end-all goal of lighting. What I AM comfortable saying is that the plants have evolved with the sun in place. Artificial lighting that does a good job of emulating this spectrum would at the very least be a great place to start.
Abiqua
Well-Known Member
“Color rendering” describes how an object appears to the human eye based upon an ideal or natural light ...
http://eu.mouser.com/applications/lighting-cri/
and your right in theory, a higher CRI would make us assume that might be the best light we can see [really bright mid day summer sunlight], that a plant would like....and an adjustment has been made to the original R9 to R14....so 14 spaces are tested individually to achieve CRI.....
but anthro vision is a weak tool for plant calibration...I want to see what the DNA does when it interacts with a photon indirectly...5 years maybe less....
Rahz
Well-Known Member
Is it the Sun or the Mcree curve we should be emulating?
I'm all for a broad white spectrum, but adjusting blue and orange up to meet the Sun's output? I don't see that as a great deal. It's possible LED, having enough blue and a spike in red at the top of the Mcree curve, is more ideal than the Sun.
I'm all for a broad white spectrum, but adjusting blue and orange up to meet the Sun's output? I don't see that as a great deal. It's possible LED, having enough blue and a spike in red at the top of the Mcree curve, is more ideal than the Sun.
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I think emulating the sun is the ultimate goal. BUT it costs a lot of $$ to emulate the sun. so figuring out where we focus the watts, to reduce the cost is the real challenge. Its easy to say I'll mix some 3K cobs with some 65K cobs, but it may be more efficient to supplement 3K cobs with some Royal Blues+UVA+Deep Red.
Meinolf
Well-Known Member
The cheapest for that matter. But it may be true especially for generations of strains bred under bulbs.
Its been shown that
- green light penetrates deeper in the canopy than light based primarily on chlorophyll a & b peaks red/blue.
- is effective in driving photosynthesis
- avoids oversaturation and burning from high levels of red/blue monos. Plants can use a higher ppfd with a wide spectrum light, that includes green.
Rahz
Well-Known Member
I'm not knocking green light, just questioning whether sacrificing some blue and green from the suns spectrum for some extra red is a bad deal.
I think we're both theorizing, and that's cool. There actually is equipment out there that could be tuned to test these theories. More money than I have to play with though.
I think we're both theorizing, and that's cool. There actually is equipment out there that could be tuned to test these theories. More money than I have to play with though.
Scotch089
Well-Known Member
@stardustsailor
I'm rereading some things out of this thread to revamp myself, I noticed you recently posted something about leaving out monochromatic and siding with the light side, what has made you stance changer? I am still stuck in my day one beliefs (which you and others have agreed upon at one time, w+r fo life!) But am always open to hear why another option may be better suited.. the floor is yours sir!
Just curious what other tests/data may have been released in time
I'm rereading some things out of this thread to revamp myself, I noticed you recently posted something about leaving out monochromatic and siding with the light side, what has made you stance changer? I am still stuck in my day one beliefs (which you and others have agreed upon at one time, w+r fo life!) But am always open to hear why another option may be better suited.. the floor is yours sir!
Just curious what other tests/data may have been released in time