Light spectrum research

[cture]

Due to my LED total fuckup ) i had carried out a little research.
Used various sources, and they state various date for instance
Alphabetical Index of Photochem CAD Spectra different absorbtion spectra for alfa in methanol and ethil.
Here is tha spectrum I have figured out for now.

chlorophyll a 420 660
chlorophyll b 430 625
b carothene 450
P680 Photosystem II 680
p700 Photosystem I 700

what you think?

cture Reviewed by cture on 06-29-2007. Light spectrum research Due to my LED total fuckup :)) i had carried out a little research. Used various sources, and they state various date for instance Alphabetical Index of Photochem CAD Spectra different absorbtion spectra for alfa in methanol and ethil. Here is tha spectrum I have figured out for now. chlorophyll a 420 660 chlorophyll b 430 625 b carothene 450 P680 Photosystem II Rating: 5

[rhizome]

hope this works

[cture]

could you give me a link to the origin of this picture?

[rhizome]

Actually, I can't- I've had that one kicking 'round forever as a teaching tool. Wanna say I pulled it off MadSci.

But here's another, more detailed version, which I can absolutely attribute to the University of Arkansas Little Rock , Dept of Botany.

Source URL http://www.ualr.edu/botany/spectra.gif

Took about thirty seconds to find- surprised you've never seen it. Same charts on the box of every agricultural HID.

[cture]

photosynthesisi is not the only process in the plant that is regulated by light

[rhizome]

I agree- your point?

[cture]

well if we just take two peaks in blue and red for lightening will the plant develop and grow as it would grow under the sun or some some changes in plant growth and development may occure?
The graphs of spectra you provided me don't have any pecise data, do i have to prin iot out and measure with a ruler the wave lengths of peaks? If we know the exact wavelengths we could assemble more efficient led lamp.

[rhizome]

Lemme look around and see if I can find one w/ better granularity.

Think you could get away w/ whatever's cheap @ about 3k and whatever's cheap @ around 6500- don't know anything about LED pricing per se, but seems as though when I've bought other components you paid about the same for 10 pcs as you did for a hundred, as long as the part # was the same.

How many discrete wavelengths\ color temps \ part #'s are you willing to put up w/?

Looks ( and I am a total layman here) as though you could rough the curve w/ maybe 5 part#'s?

Heh... lemme see if I can find something that we could at least drag into paint and throw x/y scales over... now that I know what you're after...

[cture]

Rhizome, nice to see respond from you
Have a look at these graphs Chlorophyll a, diethyl ether
Lightening is more ciomlex than I thought. I have never been in biology that far since I was at school.
Basically all light from sun is used for plants growth. For example Table 3
The aim iz to determine peaks for all of plant pigments, accesory cells and light harvesting complexes, then to find out the proportion of content in the plant in order to combine led lighter using leds with known wavelenghts to meet this proportion, this will ensure absolute lightening so all plant cells will be driven in action.
For example:
chloro a peaks at 420 660 nm number of cells per cm^2 100 (say we need 100 leds)
chloro b peaks at 430 525 nm number of cells per cm^2 50 (we need 50 leds)
PSII triggered by 680nm light number of cells per cm^2 4 (we need 4 leds)
this is just simople illustration of what I mean.
But there are more factors that can affect light spectrum such as veg, flowering, etc

[rhizome]

OK, so we're already looking at leds emitting @ 420,430,525,680 nm anyway.

Not all photomediated responses are gonna be wavelength determinate- We're gonna need to determine which are , and which will need to otherwise managed.

I'm also wondering about availibility/cost of leds tuned to these precise wavelengths- wondering if it makes sense to build in some slop ie leds @ 655 & 665 instead of 660nm.

Seems like color temp variations could be managed by switching-

know nothing about LEDS- are they voltage dimmable?

Still looking for more precise data.

Anybody got a Lexis/Nexis account?