sixstring2112
Well-Known Member
I can tell you for sure my blurple mars panel grows some seriously dank weed,its just a design flaw they have with thermal management and trying to cut corners.but you wont see a fuller spectrum with ir built in.
You missed my point but I realized I had mistaken (remembered incorrectly) chlorophhyll A/B work was done by Anderson and Evans....But my comment still stands McCrees data is flawed@Johnnycannaseed1, The Mcree study provides a full spectrum response and isn't the classic red/blue peaked chlorophyll response. There are other issues with the study but it's what we've got to work with.
Agreed, almost wondering if were pretty much splitting hairs when it comes down to CRI and spectrums of light.Great stuff here, I can't help but wonder what the plants themselves think. Theory vs real world validation, which are the most significant factors in actual plant growth?
But Red and blue solely can be used to greater effect than white light depending upon what you are growing...seems you have missed the points in my post.Incorrect, it's the people who only look at chlorophyll absorption who think Blue and Red is all you need. McCree also shows quite high efficiency in all wavelenghts.
Incorrect see reply above... as Satived has correctly pointed out people are cherry picking Mc Cree data, but Mc Cree data was also cherry picking and is incomplete... That is not very scientific!McCree puts this notion to bed. So yes, the burple crowd is obviously been proven wrong. At best you can use that for additional lighting in greenhoues which already get most of their light from the sun.
So because it is held up as some type of standard that makes it right is that what you are saying lol? Plenty of things have been held up as standards in the past only to crumble over time.McCree is still the standard. Although by no means is this supposed to be a light recipe.
So by your logic because everyone else is doing it guess you are saying I should be a follower lol....Your comment here clearly shows you do not understand what I have previously said...I have explained in another thread the issues and the solution, wonder how many different crops under different spectra you have tested?Everybody in horticulture works with those McCree charts (RQE + Absorpance). PAR meters are based on that chart. Yet you claim it's "completely flawed". You will have to provide some evidence on that and also show what everybody should be using instead. It's a bit useless to say everything is wrong if you can't suggest something better.
Equally good post to which I could not agree more...you are right people are misinterpreting what they are reading or worse still they are making incorrect assumptions - Then others follow - and before you know it a trend has developed which in turn becomes "the standard"... what happened to real world testing and creating your own standards based upon observation aka "real" science lol!Good post.
Additionally the results of a single leaf still gives a very incomplete picture of the results on a plant with more than one leaf layer. The MCCree curve is cherrypicked over more complete info but ironically it only shows what a poor choice 3500k is.
Notice the ~450 an ~660 in the blue graph (and the ~625, matching very well with cri 90).
Blurple led manufacturers didn't make up any wavelengths. They, like the naysayers now, cherrypicked a few graphs they thought they understood and used those to convince themselves and others.
If anything, what both show is that 3500k (as a color temp, not perse individual cob....) is a poor choice. Red should be highest, rest only enough. It's that last part where plant species differ most, and what we don't know exactly. There's no reason to choose so much blue and green, it's far less efficient for the plant. 2700k cri 90 is a good alternative to a more expensive WR led light (the ideal for now).
The blue YPF curve above still does not account for the effect blue has on the accumulation of different accessory pigments and vice versa, and does not account for the effect of for example FR on photosynthesis throughout the crop rather than measuring a single leaf. In reality that blue light become less efficient much faster than red (ironically making red even more efficient relatively...).
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Funny how the value of a "few" % more or less light fluctuates so fast around here to suit one's preconceived notions. Compare those "few" % beyond 700 of the orange curve to the ppf difference in % between cri80 3000k and the cri90 2700k... in Malocan's post.
Obviously the difference in light output is so small already either way. Obviously your posts reek of bias towards 3500k. Obviously the 3500k lights people have above their plants and the ones you sell are not more efficient or higher in output than what's possible with 90cri. That is far more a matter of cob brand/bin/version/amount/driver. Letting that dictated the spectrum for plants for a grow light that should last for more than a few years is just... unwise.
That's just where you connect the dot to, to blurple, appareantly the only thing where the line attached to in your limited reference frame. Doesn't mean it has anything to do with blurple, just means you have a few gaps in your knowledge and playing the one-eyed king parroting riu nonsense at the dutch forums has "grown to your head"... Citizen isn't the only one who suggested something very similar and has nothing whatsoever to do with burple.
Does an HPS light not fall within the curve or something? What are you getting at?A Hps lamp works, are plants underneath it following Mc Cree data?..Or the lovely swoosh of the Mc Cree curve?.
What about crops that are grown under alternating light regimes how do they fit into Mc Cree data?
I dont think it was developed with any of that even in mind. I wouldnt knock it for not being able to answer things it was never intended to answer.Or what about the effects of monochromatic sources under white light?
Let alone photo-period manipulation and how all of the above affects different plants in different ways...
Mc Cree data is one dimensional at best, not to mention it tells me absolutely nothing about the effects of light on post harvest yields and quality,
There is no way I would use it as a reference point, just because of the fact of what that experiment fails to take into consideration.
Each 5nm span of a spectrum has it's percentage of output determined. When the Mcree factor is applied to each as a number from 0 to 1 it changes the output of each 5nm span to the percentage of it that causes photosynthesis in the Mcree study. My digitized plant response climbs quickly to .5 and stays in the .500s up to around 550-560 at which point there is a steady climb to 625 then a slight pause and an uptick to 665-670 and after which a steep decline. This is the logical plot if we take out the two high samples on the left and the two low samples on the right.again i may be overthinking it, but it seems like this would be double counting the spectrum/absorption effect, in other words, every spectrum is different and then you throw a factor on top of that, it would seem to over-emphasize that portion of the data
Did you even look at the results? How can that possibly be biased towards 3500K? It didn't win pre or post conversion. I have an interest in getting to the bottom of the issue same as you. I was rooting for high CRI and was suprised 3000K 70CRI came in first even after the Mcree conversion. It's the exact opposite of what you preach so I suspect you will have issues with it, but it's not my bias that's providing the results. I'm just providing some controlled test results and a spectrum weighing system that favors low K and high CRI profiles. So again, how am I reeking of bias? You must either agree with the test results, or suspect that I somehow plotted to make 3500K look good... by inflating the 3000K spot reading results.Obviously your posts reek of bias towards 3500k.
Because HPS contains relatively little blue and lots of orange, it will score quite high against the Mcree curve potentially better than some or all of the cob samples. I haven't digitized any bulb spectrums but I'm sure that according to Mcree HPS should work well despite not having a swoosh. It's more a matter of where that light is falling in the Mcree shoosh.A Hps lamp works, are plants underneath it following Mc Cree data?..Or the lovely swoosh of the Mc Cree curve?.
There is no way I would use it as a reference point, just because of the fact of what that experiment fails to take into consideration.
I thank you for going to the effort of testing these and creating some data.Because HPS contains relatively little blue and lots of orange, it will score quite high against the Mcree curve potentially better than some or all of the cob samples. I haven't digitized any bulb spectrums but I'm sure that according to Mcree HPS should work well despite not having a swoosh. It's more a matter of where that light is falling in the Mcree shoosh.
"A widely used estimate of the effect of light quality on photosynthesis comes from the Yield Photon Flux (YPF) curve, which indicates that orange and red photons between 600 to 630 nm can result in 20 to 30% more photosynthesis than blue or cyan photons between 400 and 540 nm (Figure 3)[3], [4]. When light quality is analyzed based on the YPF curve, HPS lamps are equal to or better than the best LED fixtures because they have a high photon output near 600 nm and a low output of blue, cyan, and green light [5]."Because HPS contains relatively little blue and lots of orange, it will score quite high against the Mcree curve potentially better than some or all of the cob samples. I haven't digitized any bulb spectrums but I'm sure that according to Mcree HPS should work well despite not having a swoosh. It's more a matter of where that light is falling in the Mcree shoosh.
Lol have fun with thatThat's a wrap, going back to hps now
The Chlorophyl chart is in their datasheet ..... so ... ehm .... yeah I connected that "dot".That's just where you connect the dot to, to blurple, appareantly the only thing where the line attached to in your limited reference frame. Doesn't mean it has anything to do with blurple, just means you have a few gaps in your knowledge and playing the one-eyed king parroting riu nonsense at the dutch forums has "grown to your head"... Citizen isn't the only one who suggested something very similar and has nothing whatsoever to do with burple.
a coincidencelumens are for humans sure....but also plants like them
hence the 70 CRI getting better scores
3000K80CRI 905Moving a much lower red peak by a few Nm to the longer end of the spectrum is not going to overcome a huge deficit in quantum yield from CRI90.