Lighting Spectral Data

It’s always the same when tech geeks get involved. You should see the endless arguments about cables on hifi sites :laughing:

A ‘guru’ states this new shit is the best shit ever and the herd polish the turd. Then another guru disagrees and war breaks out, small minds use big words to impress the faithful and put down the unbelievers. Same as it ever was :joy:

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I’m going to a cannabis convention this weekend so I can totally geek out - Fluence will be there and many other lighting companies, I’ll be talking to all of them “tell me about your diodes…” :smile:

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Watch their eyes when you ask that question, you might even see that sales smile slip a bit :laughing:

Tell them you can advise them about cryogenic treatment for those diodes which will re-align their conductor’s crystal structure so it conducts better which results in an efficiency gain

They just need to provide several examples of their latest products - for evaluation purposes, etc :grin:

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Had a great time at NECANN convention today, it’s become huge. Fluence bought a big crew up from Texas, I got to ask my questions and check out all the lights. One guy told me they are indeed using Samsung white diodes & Osram colored ones - he said they prefer the Samsung white diodes and have no plans to change.

Both the Fluence and Urban-gro people advised me that changing spectrum should not shock the plants much - they said changing intensity is the real problem. Told me I should get an Apogee light meter - it costs $500+, I’ll probably stick with trial & error :smile: The beam angle of my PL flowering lights is only 80 degrees, even at 50 inches away it can shock the plants.

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FWIW, there is a USB version which is a bit less. Need a PC or a MAC. And, you can usually find them a bit cheaper by watching for deals via Ebay and such.

Also, Li-cor are decent, too.

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  1. Cleaned up the OP a bit
  2. Added two unbranded UV-A LED lamps into the OP. Also see this thread:
    Anyone experiment with UVA supplementation?
  3. Preparing for the addition of more fixture / lamp measurements.
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FYI, new ‘ePAR’ sensor from Apogee. Revision on the McCree PAR range, these sensors includes photosynthetically active FR and a bit of the UV which they coined extended PAR.

For those curious, timestamp 9:08 for the ‘why’.

Some of the associated research papers described in the video:

Substituting Far-Red for Traditionally Defined Photosynthetic Photons Results in Equal Canopy Quantum Yield for CO2 Fixation and Increased Photon Capture During Long-Term Studies: Implications for Re-Defining PAR
Substituting_Far-Red_for_Traditionally_Defined_Pho.pdf (1.7 MB)

Far-red photons have equivalent efficiency to traditional photosynthetic photons: Implications for redefining photosynthetically active radiation
Bugbee 2020 Far Red Results in 14 Plant Species.pdf (3.0 MB)

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interesting, too bad I just bought the older quantum sensor last year! Looks like this will only be a few % different from the old one though.

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Oh, that’s a perfectly fine sensor. I have one of the older models as well.

Hey Northern. Have you ever used the light meter app? I was curious I use it on mine. Wanted to know if it was a waste of time.

I have not used those phone based light meters / PAR meters.

They’ll probably produce sufficient accuracy for what an individuals needs. It will also likely differ from phone to phone and have other limitations since the sensors, filters, gain, linearity of the CCD/CMOS camera will vary. Some applications may spell out the phone models that the application has calibration data for. There was a thread here talking about using such applications.

For more accuracy (if you a running a large operation) or scientific grade accuracy (if you are running studies or tests), you’d want a true PAR meter or, in some cases, going as far as a spectrometer.

p.s. a true par sensor makes adjustments for the incident angle of the radiation. The angle relative to the sensor will cause an error. Correcting for the error is essential for accurate metering of PPFD for instance. You don’t get that from a phone camera but, then again, do you need that level of accuracy.

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thoughts on this spectrum? I’ve got an fce4800 on the way but want to fill out a 4x8 and the $350 price tag on this lights pretty tempting.

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It looks good to me! tested by DLC, that price is really low for 440W

https://qpl.designlights.org/horticulture?search=volt&dlc_session_id=&dlc_last_company_id=

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@Northern_Loki

I hope this information is useful. I think it adds to the reference data you have shared thus far.

Gavita DE HPS 1000W spectrometer data from from 357 to 830 nm at <1 nm increments created by University researchers (attached as txt file). Along with two SPD charts from the spectrometer data attached.

GAVITA 100W SPD.txt.pdf (48.6 KB)

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Here’s a great document that I noticed wasn’t shared in this thread. They tested quite a few LED brands and products and may benefit this thread:

LED and HID Horticultural Luminaire Testing Report
Lighting Research Center, Rensselaer Polytechnic Institute (2018)

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Regarding the McCree curve, if my memory serves, in one of Dr. Bugbee’s videos at Utah State, he discusses an interesting realization that his students came upon while studying McCree’s work. I don’t recall exactly the realization or which video includes his comments on McCree’s work. But I remember that the realization was new, and I found it interesting. I will try to find it again and post it here.

If someone knows what I’m referring to please share.

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That’s excellent. Thanks for sharing @anon11552397.

… that IR peak :wink:

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LOL, I thought you would notice that, @Northern_Loki. Nothing beats useless IR to heat up leaves to the detriment of transpiration, CO2 fixation, calcium and boron mass flow uptake and diffusion, and VPDleaf!

I use “VPDleaf” instead of just “VPD” because so many people and companies are unaware that VPD needs to take leaf temperature into account. It is meant to distinguish between environmental VPD ("VPDair) and plant science VPD (VPDleaf).

See:
Nelson, J. A., & Bugbee, B. (2015). Analysis of environmental effects on leaf temperature under sunlight, high pressure sodium and light emitting diodes. PLOS ONE, 10(10).

On a side note, if you wanted to share all of your spectrometer data test results, I would be happy to enter them into my updated version of Knna’s “Bulb analyzer v2” spreadsheet. Then share the results in this thread or another thread.

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Added Vivosun’s VS4300 to captured spectra.

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STATE OF THE CANNABIS LIGHTING MARKET via Fluence

Primarily a marketing piece but there are some interesting insight regarding LED application and spectrum. One suggestion, for instance, is that when a certain light intensity is obtained, the spectral quality of the light is of less significance.

CBT-Oct-2022-SOI-web.pdf (1.6 MB)

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