Cree CXA analysis

PICOGRAV

Well-Known Member
Looks like the author of that paper tried to up his citation score, seeing how often he refers his own articles. You may think it sounds deep but it is actually pretty much bullshit.

If you doubt the quantum nature of light, try looking through night vision goggles. You can then see the the impact of single photons as they come in.

You haven't really proved anything but the Bridgelux arrays measured better then the Cree's, I could have told you that without the complex calculations you preformed and you refuse to process data that actually is more relative to the discussion, comparing HID lighting to LED lighting.

From this day forward, your life, will become seeming less relative...
 

MrFlux

Well-Known Member
Good catch guod, did not realize the man was a nobel prize winner. Feel free to share any insight that the paper gives you.
 

stardustsailor

Well-Known Member
Hard to believe, almost, that's a rather huge difference. And the High CRI phosphor is converting more Blue light, too. Man, those Deep Red and IR wls really suck up a lot of juice.
Yes that is true ...
But ...
Well ,I'll not do the 'talking' this time ....


In addition to the light visible to humans (400 nm – 700 nm) plants “see” or use other radiation too. The 400 nm–700 nm wavelength range is called “Photosynthetically Active Radiation” or PAR. Much of the light that plants need is in this range, but for optimal growth result, UV light (280 - 400 nm) and/or far-red light (700-800 nm) might be important. For example far-red is critical for the flowering of many plants. All light is not equal to plants, ie. some areas are more important than others.
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1) Valoya AP67 – General Growth Spectrum

For vegetative and generative growth. Performs very well with a large variety of plants, ranging from cucumber and tomato to lemon trees and even snow algae. It provides strong vegetative growth and early flowering of plants. With some leafy green plants elongation is achieved, while with some flowers the growth result is a compact plant. The AP67 spectrum has also been shown to promote quick and good rooting. The AP67 is strong on far-red (about 18 % of the total radiation) and has no UV radiation. Suggested use: Suitable for most vegetables e.g. cucumber, flowers and tree seedlings. Also positive results with algae. Appearance to humans: Pinkish light, quality control possible, good working environment.
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A good balanced ratio between red and blue light, needs to be complemented with far-red and green in right proportions for the right applications.
For example far-red, 700–800 nm is critical for flowering of many plants. Less is known about the green, 500–600 nm area, but recent research is finally able to conclude that this is also important for plant development. Besides being potentially harmful, plants also show photomorphogenic responses to UV-B (280-315 nm) radiation. Both UV-B and UV-A (315-400 nm) radiation are important in inducing production of phenolics, anthocyanins (coloration) and antioxidants in plants. Thus the full spectrum from about 350–750 nm at a suitable light intensity is interesting in plant cultivation. The key is then to create a light which is optimally suitable for its task, by balancing the different areas so that the plant gets the right energy and signals to achieve the growers’ goals.*
http://www.valoya.com/plants-light


*Even if it means you'll have to "Sacrifice" some " efficiency " ....
For example :

In need of a broader amber/red/deep red/ NIR spectra ?

-Either you go the multiple monochromatic leds ,way ( -Yellow this -amber this-red that-red this -Infra red that ..)...

Or

-Have some high CRI WW here'n'there,amongst deep/hyper red leds (640-660 nm for example ) and plenty of WW/NW of lower CRI....

Each way has pros 'n' cons ....

Especially for small scale indoor cultivation sites ?

Just sit and think for a moment which way suits best the needs ( and limitations ) and why's that so ....
:dunce:
 

Positivity

Well-Known Member
I'm all for giving up some efficiency for better growth.

all I can say about far red is damnnn....easy with that stuff. Took one for the team on my current grow...lol. I've never seen such crazy stretch. The ledengin 10w (@6.5w 700ma) must be kicking out some IR...
 

stardustsailor

Well-Known Member
I'm all for giving up some efficiency for better growth.

all I can say about far red is damnnn....easy with that stuff. Took one for the team on my current grow...lol. I've never seen such crazy stretch. The ledengin 10w (@6.5w 700ma) must be kicking out some IR...
I've experienced first -hand the stretching induced by 48 ( out of 108 in total ) Warm White leds 2700 K ,95 CRI .....
And it is way much ......(Lots of NIR,there ....)
But Flowering is awesome.....
Well.....Kinda ....
Veg sucks ,big time so it impacts flowering(big-time) ,
meaning flowering could 've been even better (Lotta better )...
 

bbspills

Well-Known Member
So far my plant is loving the Cree CXA3050 2700K LEDs. Here she is at 11 days of 12/12 and there are flowers all over. Stretch wasn't out of control either as you can see from the bigger branches I tied down there are lots of bud sites up the stem.

I'm really interested to see how much more upward growth and flower development I get in the next week or so as she's really far ahead of most strains I've done this early in flower. Perhaps she's just a fast flowerer, but I cannot deny the amazing growth I am getting from these 2 LEDs.

IMG_20131028_183730_833.jpg
 

bbspills

Well-Known Member
By the way, I only supplement far red (IR) 15 minutes to lights off and then continue 15 after lights off. It's well proven that improper ratio of red to far red IR throughout your light schedule promotes excessive stretching as it makes the plant think it's shaded.
 

tags420

Well-Known Member
I never paid too much attention to CRI. If it was higher and still had good/more output then it was a win, but I usually focus of the output power as a bigger determining factor. But it is very interesting to see what it does for the spectrum. The slight shift really fills out the 660nm and other reds. Like stardust said...they can be used in sync with better output diodes to fill ad complete the spectrum.

Here is the older Nichia that all the flashlight guys cum for.
92CRI @4500k. Does 110lm/w in the b10(actually obtainable too), pretty good for high cri.
2z66yqw.png
Compared to their newer higher output but 80cri white version in 4000k
http://www.nichia.co.jp/specification/products/led/NVSL219B-E.pdf
(I can't get the graph off the data sheet, but it's in there)
 

bbspills

Well-Known Member
I think we need a new industry standard CRI index for us to follow

I call it : Cannabis Rendering Index

Let me know when that index is available and sign me up for all the 95-100 CRI LEDs with 200 lm/w!!!!


All joking aside, we'll be seeing 200 Lumen per watt LEDs real soon.
 

Rrog

Well-Known Member
Terribly exciting.

I'm thinking of structures that could allow many small panels on articulated arms to be arranged around taller plants.
 

PICOGRAV

Well-Known Member
I think we need a new industry standard CRI index for us to follow

I call it : Cannabis Rendering Index

Let me know when that index is available and sign me up for all the 95-100 CRI LEDs with 200 lm/w!!!!


All joking aside, we'll be seeing 200 Lumen per watt LEDs real soon.
Check this:
http://www.fara-led.com/content/en/16/

LPS lights have negative CRI! but this rating is almost useless unless you take into account the CCT.

2700K 97 CRI, probably not as good as a 5000K 70 CRI.
 

tags420

Well-Known Member
CRI = Color rendering index, CRI and CCT (Correlated color temperature) are the standards for measuring light.
They are standards...not "the" standards. There is no measurement that takes all things into account. Indagros's v-c-f system is one of the closest showing the mix of spectrum+output+plant needs that I know of.
http://www.inda-gro.com/pdf/MeasuringPlantLight.pdf
It's not perfect, but it is plant orientated lighting science, not just pretty colors.
 

Positivity

Well-Known Member
By the way, I only supplement far red (IR) 15 minutes to lights off and then continue 15 after lights off. It's well proven that improper ratio of red to far red IR throughout your light schedule promotes excessive stretching as it makes the plant think it's shaded.
I read all the reports and followed a few grows. It also seems though that having the RIGHT AMOUNT on 12/12 can have a similar effect. It was just a test to see it it with my own eyes what happens with a lot of IR. I'm going to try 1/3 the amount, with a few blue leds added, before I resort to having a seperate fixture. If nothing, I learned first hand, which was my goal.
 
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