nevergoodenuf
Well-Known Member
You can't compare them like that. Each one will have different peaks if you compare at a set wattage. You would have different max peaks if ran at the same wattage.strips, so PAR will be lower. see orange region:
CRI test and Mcree weighted results
- Thread starter Rahz
- Start date
Schalalala
Active Member
These photons do not drive photosynthesis so its useless for a PAR (Photosynthetic active radiation!) meter to count them!
tazztone
Active Member
have you actually looked at the McCree curve? there is stuff going on beyond 400-700nm
i just wanted to show (relative) spectrum differences
Greengenes707
Well-Known Member
RQE values...aka McCree curve hard data. How effective each nm(every other nm) is at driving photosynthesis.
McCree is credited with quantify and defining the range PAR range(and he did). But what is published and regurgitated by others is not exactly what he discovered/reported/presented.
The data shows and proves the true PAR range of 316nm to 782nm being active at driving photosynthesis. Now days the horticulture lighting world is trying to spin it as "Bpar(biological par)" range...aka the actual McCree curve range, not a grade school simplification. That could even be narrowed to 10% effective threshhold and still be well outside the perpetuated "400-700nm" range. So you can call the light outside 400-700 whatever you want...but the facts are it drives photosynthesis.
Not to mention it's signaling and morphological aspects for phytochrome and others but we will stick to the action of driving photosynthesis.
I have not said any method/approach to lighting spectral importance is better than the other. Just presenting the facts on the matter for people to make an educated decision for themselves with the actual data.
They are only relative when to itself. When shown in absolute values, you can see that though some may have different relative ratios, but they still contain as much of more actual amounts of certain nm/ranges.
Here is an old chart of all the vero10's in each SPD at the same output. Higher CRI's have caught up a little more to the 80cri since this chart, but still pretty valid.
Schalalala
Active Member
Yeah, wow, a weighing factor of 0.4 to 0. So that is the big pro argument for CRI90 LEDs? Besides that: The RQE chart is just one thing. Leaf absorption chart the other. Combine these two to get a proper, meaningful action spectrum and realise that CRI90 LEDs are pretty wasteful....I mean.... the far red study is interesting, but thinking its a smart idea to create the far red photons with CRI90 LEDs is - in my opinion - the opposite of smart. However, buy your Vesta stripes and be a happy man
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BuddyColas
Well-Known Member
I agree. A PAR sensor will leave the +700nm photons uncounted, and a 90CRI LED will have more uncounted photons than a 80CRI LED. BUT, the photons above 700nm are not discounted by the plant! I agree with GG that the "True PAR" range of 316nm to 782nm is more representative of what is actually seen by and acted on by the plant. And I think the girls like that "deep red" and "far red" action!
Up front, I have not actually tried it myself...YET! But I did lay down $65 to actually try it on a grow and see for myself.
So with 6 each 22" VESTA strips, that will be about 150 watts of 2700K and 150 watts of 5000K each temp. on separate HLG-185H-C1050 drivers. Then I can dial up each spectrum for veg, transition and full flower. At least that is the plan at this point.
More actual experience to follow. Out of respect for Rahz and his thread, I'll probably start a thread when I get it built!
Note: Went to my PO box...and it was...empty!
But to Digikey's credit, they shipped same day I ordered and for free.
(patience Grasshopper)
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Rahz
Well-Known Member
Yeah, wow, a weighing factor of 0.4 to 0. So that is the big pro argument for CRI90 LEDs? Besides that: The RQE chart is just one thing. Leaf absorption chart the other. Combine these two to get a proper, meaningful action spectrum and realise that CRI90 LEDs are pretty wasteful....I mean.... the far red study is interesting, but thinking its a smart idea to create the far red photons with CRI90 LEDs is - in my opinion - the opposite of smart. However, buy your Vesta stripes and be a happy man
It does well enough that we're still trying to figure out if one spectrum is better than another when the lower CRI samples generally do better on paper and under the meter. I don't think there's much difference getting the deep red from COBs vs top bin monos, but if someone has some math suggesting otherwise I'd be curious to see.
Rahz
Well-Known Member
Thanks and understood, but drive current and efficiency at nominal will affect the final numbers. Last time I checked (which has been a while) the best 660s were hitting around 50% under driven. It didn't make sense at the time, not much difference for the increased upfront cost.
Schalalala
Active Member
With hyper reds it really depends on the bin you get imo. And they are expensive. Osrams top bin pushs out 3.91 µmol/J @ 350 mA. Thats already better than a phosphor converted LED physically (at least with my understanding) can be (3.7 µmol/J @ 100 % efficient).... https://dammedia.osram.info/media/resource/hires/osram-dam-4651433/GH CS8PM1.24.pdf
But don't get me wrong. I do not want to advert hyper reds here.
(But I advert using proper far red LEDs when someone wants - for whatever reason - far red light.)
But don't get me wrong. I do not want to advert hyper reds here.
(But I advert using proper far red LEDs when someone wants - for whatever reason - far red light.)
Stephenj37826
Well-Known Member
SSL 80 660NM is good.....Oslon square 660NM= Whaaaaaattttttt!!!!!!!!!!!!!!
Greengenes707
Well-Known Member
I know right. But no 80* option, which for me what was so damn appleaning about osram. I would settle for a happy medium. And single bin access would be great. Been dealing with osram lately and it's a little frustrating at times.
Slinging PAR
Well-Known Member
Gee I wonder why.....
Schalalala
Active Member
Hmmm these ones are basically two normal Oslons SSLs in one package... must have beefy chips (would love to see a die shot!)... (Datasheet: https://dammedia.osram.info/media/resource/hires/osram-dam-5066839/GH CSSRM2.24_EN.pdf .... osrams page... jesus fucking christ, worst website in the internetz)
@Greengenes707
I always thought that there is just one bin on an roll, but when buying you don't know which one they deliver, correct? If I got that right, than thats completely stupid from the beginning imo. Have you called them and asked whether it is possible to get a single bin?
Stephenj37826
Well-Known Member
Like pulling teeth lol. Requested quote.......2 months later wants to meet...... to tell us we will get you a quote........ 2 months later gets quote..... lead time is 20 weeks...... I'm afraid the world might end before we see parts lol. We ended up going a different route, adding a few more, and cutting current. Should get us close for now........ then the question is can you trust you will get same bin as sample in production qty......
Stephenj37826
Well-Known Member
With the other company we are guaranteed flux and voltage bin which we require generally.
Randomblame
Well-Known Member
Because Bridgelux doesn't offer monochromatic diodes like Cree, Osram, Phillips, Prolight and others do.
