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Measuring Plant Light Can Can Be Confusing.


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I have enjoyed many spirited discussions with gardeners re the way plant lighting systems are field measured and how manufacturers publish their lamps output data. As a direct result of these discussions I recently was asked to help contribute to a paper that proposes how manufacturers might consider publishing their lamp's outputs in a format that identified raw usable wattage in the the three peak photosynthetic absorption regions. Think of it as like an N-P-K system for rating plant lighting.

 

In developing this document we used manufacturer data that was available at the time of this publication from a variety of manufacturers websites. Nothing in this document is meant to construe that we are suggesting that any one technology is better than the other. Our interest in developing this document was to simply present another way of viewing how artificial plant lighting can be represented in a way that does not confuse the gardener with information and values that may be mostly irrelevant when it comes to selecting the best lamp for their needs.

 

While this report was sponsored by Inda-Gro the tables don't particularly favor them or some of the other technologies being compared.  This type of comparison still requires interpretation by the reader as to what the values actually mean.  I think a comparison of the technologies as detailed within this documents 5 most common specification techniques implies that by relying on the numbers alone you can be left with a sense of one technology is 'better than another' for occupying that coveted space above our garden. However a closer analysis of the data reveals that if you've actually grown with the supposed 'superior technologies' plant response is dictated by forces greater than just a mfg claiming 'my number is bigger than yours so it must be better' type of marketing mentality. 

 

The tables towards the end show some pretty interesting statistics when you see how much energy emitted by some of these technologies goes into regions that historically are not attributed as beneficial to plant development.   The numbers I found most interesting are the percentages that each of these lamps emit in the visual regions as compared to the vegetative and flowering regions.  Which reinforces my belief, that at the end of the day, it will always comes down to plant response which does in fact, trump many of these claims.

 

http://www.inda-gro.com/pdf/MeasuringPlantLight.pdf

Edited by chazbolin
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Thanks Vivo!  I'm not here trying to promote any one technology over the other.  I just thought the way to measure lighting is to push the values to be shown in the 3 peak absorbance regions and these tables at the back of the document provide a pretty good indication of what having these values could help tell the gardener about the lamps they are considering buying.

 

But to your question; I lean to induction because of phosphor stability and they run 1/3 the heat as compared to HID.  I've been running the same lamps for going on three years now.  For the most part I'll have one veg room feeding 2-3 flower rooms the only difference is I add Pontoons to pick up chlorophyll A @ 660nm and at lights out I get the 730nm wavelengths to instantly induce Phytochrome.  You can see their website links to their traditional gardens FB page but if you wanna see weed gardens but there is another link which is not off their website which is all medical @   https://www.facebook.com/photo.php?v=561019447283693&set=vb.262974713805120&type=3&theater

Edited by chazbolin
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Thanks Vivo!  I'm not here trying to promote any one technology over the other.  I just thought the way to measure lighting is to push the values to be shown in the 3 peak absorbance regions and these tables at the back of the document provide a pretty good indication of what having these values could help tell the gardener about the lamps they are considering buying.

 

But to your question; I lean to induction because of phosphor stability and they run 1/3 the heat as compared to HID.  I've been running the same lamps for going on three years now.  For the most part I'll have one veg room feeding 2-3 flower rooms the only difference is I add Pontoons to pick up chlorophyll A @ 660nm and at lights out I get the 730nm wavelengths to instantly induce Phytochrome.  You can see their website links to their traditional gardens FB page but if you wanna see weed gardens but there is another link which is not off their website which is all medical @   https://www.facebook.com/photo.php?v=561019447283693&set=vb.262974713805120&type=3&theater

Phytochrome....hmmm...lol..now I have to look up what that means..LOL....Interesting..

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These are regions in the plant activated by Red(660) and Far Red (730) which in nature the 730nm wavelength induces flowering Pfr instantly when the plant is exposed to that wavelength exclusively at lights out.   

 

pr-pfr.gif

 

In most indoor gardens you turn the lights off and it takes the plants a couple of hours to relax into that state.  With a short burst of 730 at lights out you can extend lights on to match the genetics outdoor photoperiod and still have enough time indoors to maximize your flowering cycles.  It's referred to as the sunset spectrum.  The sun's wavelengths change as it's going over the horizon so plants see Red, Deep Red and finally Far Red which allows the Pfr trigger flowering in nature.  This just creates that indoors so you can push a 13/11, 14/10 or even a 15/9 at flower depending on genetics.

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Yeah I guess you can say we're manipulating the market by trying to put out some useful information.  If you are taking exception to any of the values accuracies feel free to point them out.  Otherwise the information in that link represents 5 known methods of field measuring and weighing lamp mfg information.   It is just another way of analyzing the data.  It is completely unbiased in that it is based on the conversion efficiencies from electricity consumed to lamp output in these three net action absorption regions.  It will be updated on a regular basis.  In fact it just updated an hour ago to show the mathematical equations that get to these watts/region values if you wish to do so with your own lamps of choice.  The guys who I usually see having the biggest issues with these spread sheets have a special affinity to plasma.  

 

Good night to you as well. 

Edited by chazbolin
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If you would have come in, suggested the concept of measuring light by V-C-F values, and why you feel it's superior to lumen output, that'd be an interesting conversation to have. I appreciate you presenting that information. I understand why a company with a product based on this theory would want to get the information out. It seems to me that instead of that you've provided vague responses and terms riddled with suggestive comments about a line of products. Maybe that's not manipulative, maybe it's just marketing. Maybe I'm just having a bad day. It's all subjective.

 

Identifying the V-C-F value of bulbs seems to make sense, but only in combination with light intensity/lumen output. Additionally, everything I've ever read has seemed to suggest that the light spectrum and intensity quickly and continually change/diminish over the course of it's life.

Edited by in vivo
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If you would have come in, suggested the concept of measuring light by V-C-F values, and why you feel it's superior to lumen output, that'd be an interesting conversation to have.

 

I do believe V-C-F is superior than current lamp output metrics which include rating a lamp by its lumen output or kelvin.  These are not relevant terms with regards to how plants will respond to those visual spectrum wavelengths or intensities.  The charts on pages 6-7 were for everyone, you included, to see how much energy (in some cases quite high) that is emitted in the visual spectrums and then arrive at their own conclusions.  There was a lot of work that went into analyzing a wide variety of technologies and the values shown are derived directly from lamp manufacturers spectral distribution graphs.  If you grow indoors I think you will find this an eye opener.

Edited by chazbolin
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