LED Growers Unite, Who makes the BEST LED and how long has it lasted ? Cast Your Vote!!!

[Ca++]

10% blue seems reasonable. More than 30% is getting bad, and 40% is ill.

Coloured LEDs seem old tech, but I remember my cousin getting some decent money out to buy blues, which had been out of reach to him before then. They were just indicator lamps then, and superbrights existed, but were not worthy of a torch. Many early papers used prisms to split white, to get there coloured light. These were low par tests, and I can imagine the bandwidth choices being made.

 

[RequiredUsername]

THIS IS THE LAST DAY FOR THIS!

This is part of the reason I went with the light I chose. when I was looking to buy a light to replace my 5x5/1000watt grow space with something more sensible. Capital investment was a big thing for me. I dumped all my old gear for cheap and wanted to build a smaller set up for the same cost as I let go of my old large set up. I cast my vote on with a viparspectra XS2500 pro which I purchase for 152.99 at the time. Best bang for my buck and there’s was independent testing done by coco for cannabis on viparspectre‘s smaller xs1500 fixture. Driver has plenty of wire to keep the heat out of the grow space! Which is a big plus for someone like me who has no climate control.
This is an even sweeter deal than I got mine. If you don’t have one get ya one. TODAY!! View attachment 19067676

Vipar was my #1 choice for seedling and veg light. Nice even distribution. Warmish light. I Love it.

 

[acespicoli]

Proton gradients​

Proton gradients in particular are important in many types of cells as a form of energy storage. The gradient is usually used to drive ATP synthase, flagellar rotation, or metabolite transport.[15] This section will focus on three processes that help establish proton gradients in their respective cells: bacteriorhodopsin and noncyclic photophosphorylation and oxidative phosphorylation.[citation needed]

Bacteriorhodopsin​

Diagram of the conformational shift in retinal that initiates proton pumping in bacteriorhodopsin.
The way bacteriorhodopsin generates a proton gradient in Archaea is through a proton pump. The proton pump relies on proton carriers to drive protons from the side of the membrane with a low H+ concentration to the side of the membrane with a high H+ concentration. In bacteriorhodopsin, the proton pump is activated by absorption of photons of 568nm wavelength, which leads to isomerization of the Schiff base (SB) in retinal forming the K state. This moves SB away from Asp85 and Asp212, causing H+ transfer from the SB to Asp85 forming the M1 state. The protein then shifts to the M2 state by separating Glu204 from Glu194 which releases a proton from Glu204 into the external medium. The SB is reprotonated by Asp96 which forms the N state. It is important that the second proton comes from Asp96 since its deprotonated state is unstable and rapidly reprotonated with a proton from the cytosol. The protonation of Asp85 and Asp96 causes re-isomerization of the SB, forming the O state. Finally, bacteriorhodopsin returns to its resting state when Asp85 releases its proton to Glu204.[15][16]

Photophosphorylation​

Simplified diagram of photophosphorylation.
PSII also relies on light to drive the formation of proton gradients in chloroplasts, however, PSII utilizes vectorial redox chemistry to achieve this goal. Rather than physically transporting protons through the protein, reactions requiring the binding of protons will occur on the extracellular side while reactions requiring the release of protons will occur on the intracellular side. Absorption of photons of 680nm wavelength is used to excite two electrons in P680 to a higher energy level. These higher energy electrons are transferred to protein-bound plastoquinone (PQA) and then to unbound plastoquinone (PQB). This reduces plastoquinone (PQ) to plastoquinol (PQH2) which is released from PSII after gaining two protons from the stroma. The electrons in P680 are replenished by oxidizing water through the oxygen-evolving complex (OEC). This results in release of O2 and H+ into the lumen, for a total reaction of[15]

4h�+2H2O+2PQ+4H+stroma⟶O2+2PQH2+4H+lumen

After being released from PSII, PQH2 travels to the cytochrome b6f complex, which then transfers two electrons from PQH2 to plastocyanin in two separate reactions. The process that occurs is similar to the Q-cycle in Complex III of the electron transport chain. In the first reaction, PQH2 binds to the complex on the lumen side and one electron is transferred to the iron-sulfur center which then transfers it to cytochrome f which then transfers it to plastocyanin. The second electron is transferred to heme bL which then transfers it to heme bH which then transfers it to PQ. In the second reaction, a second PQH2 gets oxidized, adding an electron to another plastocyanin and PQ. Both reactions together transfer four protons into the lumen.[2]: 782–783 [17]

Electrochemical gradient - Wikipedia

en.wikipedia.org

Photosynthesis - Wikipedia

en.wikipedia.org

 

[acespicoli]

Quantum optics - Wikipedia

en.wikipedia.org

Note: a tent has 6 sides and we use one plane ... very poor use of surface area
Even with under canopy supp light

What is a M2 = "flat earth" preferable to a M3
Ok, back to LEDs

W. Heath Robinson - Wikipedia

en.wikipedia.org

 

[acespicoli]

space-buckets

Plant canopy penetration is a function of both optical power output and how focused that light source is. This is a huge consideration when building or buying a LED grow light.

spacebuckets.com

Canopy Penetration and Beam Angle​

by /u/SuperAngryGuy of /r/HandsOnComplexity​

Plant canopy penetration is a function of both optical power output and how focused that light source is. This is a huge consideration when building or buying a LED grow light.
Growing lettuce without much vertical space? Get a LED grow light with wider beam angles. Growing a 3 foot tall plant where you want the bottom leaves receiving a lager amount of light? Get a LED grow light with a narrow beam angle but have the light higher (further away from the plant) than a light with a wider beam angle.

Lighting beam angle concepts (source)
Linear lights sources such as fluorescent tubes have such a wide beam angle which is distributed along the bulb, are great for lettuce which can then be stacked on shelves. In most grow situations, the closer your light source is to the plant, the wider the beam angle you want:

• Short plants = wider beam angle
• Tall plants = narrow beam angle and have the light up a little higher so that you're not light saturating the upper leaves

Practical examples​

A 3 watt LED does not necessarily have better penetration than a 1 watt LED. I've seen such discussions in multiple forums multiple times.
Let's say we have a single LED that is a (theoretical) point light source. It's light output will follow the square of distance law of light drop off in this case. At one foot we have one unit of light which covers one square feet, at two feet from the LED we have ¼ unit of light which is 4 square feet, at 3 feet from the LED we have ⅑ unit of light which covers 9 square feet etc.
But, what if we had a 1 watt LED with a 60 degree light beam output and the 3 watt LED with a 120 degree output. What LED penetrates the plant canopy better? The one watt LED is going to penetrate better since its light is 4 times more focused (simplifying here).
I have a 100 watt LED at 120 degrees and a typical 0.005 watt laser pointer (lasers are rated on their true optical power output unlike LEDs) at what ever degrees it is. The tiny laser has better penetration. I can focus it to put tiny burn holes on the bottom leaves of a typical indoor plant in a few seconds with better optics than a cheap laser pointer.

Marketing​

Beware that some LED grow light manufacturers/importers might make a comparison and have the ruler (or whatever) say 12 inches from their light (A) and a competitors light (B). So A with a light meter puts out at that 12 inches so much more light than B, maybe even twice as much as their competitor! No, check the beam angle of both the lights.
I've seen this trick so many times by people in the trade. In most forums it's not under standing beam angle and light drop off. You just need to put the light closer if using shorter plants or low stress training and a screen of green.
A lot of distributors are coming out with multi-beam angle LEDs. The ratio of wide angle to short angle would he a handy piece of information to know as well as their general spectrum (red, far red, blue, etc).

• Read about how different light colors penetrate canopies »

 

[acespicoli]

0708.0831v2.pdf

drive.google.com

 

[acespicoli]

The following is an incomplete list of physical implementations of qubits,
and the choices of basis are by convention only.

​

Physical support	Name	Information support	|0⟩	|1⟩
photon	polarization encoding	polarization of light	horizontal	vertical
number of photons	Fock state	vacuum	single-photon state
time-bin encoding	time of arrival	early	late
coherent state of light	squeezed light	quadrature	amplitude-squeezed state	phase-squeezed state
electrons	electronic spin	spin	up	down
electron number	charge	no electron	two electron
nucleus	nuclear spin addressed through NMR	spin	up	down
neutral atom	atomic energy level	spin	up	down
trapped ion	atomic energy level	spin	up	down
Josephson junction	superconducting charge qubit	charge	uncharged superconducting island (Q = 0)	charged superconducting island (Q = 2e, one extra Cooper pair)
superconducting flux qubit	current	clockwise current	counterclockwise current
superconducting phase qubit	energy	ground state	first excited state
singly charged quantum dot pair	electron localization	charge	electron on left dot	electron on right dot
quantum dot	dot spin	spin	down	up
gapped topological system	non-abelian anyons	braiding of excitations	depends on specific topological system	depends on specific topological system
vibrational qubit[21]	vibrational states	phonon/vibron	|01⟩ superposition	|10⟩ superposition
van der Waals heterostructure[22]	electron localization	charge	electron on bottom sheet	electron on top sheet

Applied Nanophotonics , pp. 9 - 51
DOI: https://doi.org/10.1017/9781316535868.003

Calvin cycle - Wikipedia

en.wikipedia.org