The fact that an average human being does not perceive all frequencies of visible light with the same sensitivity, along with the “race for lemons” is the reason we have a plethora of “lesser white light” leds or low CRI leds. But enough with the slight off-topic…
Check “sunlight spectrum” and “full spectrum” at Guangzhou Juhong Optoelectronics, had it in my list of sellers. Proposed a review of these to the usual testers long ago around here, but guess there was no interest somewhere.
I think I have a couple 4000K & 5000K “sunlight spectrum” output spectrum files somewhere in my desktop computer, they were published long ago by some eastern europe buyer in the AliExpress product reviews section, and I downloaded them. They had infrareds. Will check later.
I forgot to ask earlier, and I know this may be a really silly question...is it possible to make my own strips? I have a feeling that to do this I'd need some very specialized equipment so it's probably not feasible, but it's still worth a shot if it's possible. I have a Hakko soldering station lol...does anyone make their own strips here?
I think a good starting place would be to have at least 800W of power over a 4x4 area for the grow light, and I'd probably have to build it and measure the setup with a Apogee quantum sensor to get a good idea if 800w would be enough to hit PPFD of 1000μmol/s.m² at a reasonable height over the plant canopy. I suspect that since the spectrum is so broad for high CRI light sources that you can actually push higher PPFD than light sources that have a lot of peaks/inconsistencies in spectral output. The way PPFD and grow lights in general are measured, all photons within the PAR zone are counted as equal, and knowing this I'm thinking that when a typical LED light that has a peaky light spectrum "burns" plants by being too intense, the light is probably too intense in certain wavelengths and if the spectrum was more even than they could handle higher flux density. Just a wild ass guess on my part, and it's something wanting to test as well.
And what is the reason to make your own led strips, when you can power up your leds with proper constant current led drivers?
Just a question, of course. Commercial led strips I've seen consist of links interconnected in parallel, and each link consisting in a few led emitters in series together with a resistor to drop excess voltage and current (links of 3 led emitters and a resistor for “12V” led strips, and links of 6 led emitters and a resistor for “24V” led strips). With such a setup not every link in the strip receives the same input voltage, this is because when you feed a strip from one of its ends, each ongoing link has to carry the input voltage to the next and there's a small drop in each of them, even if tiny. This rarely is a problem and is proportionally less pronounced in the higher voltage strips.
If I were to make my own strips for whatever reason, I would set in series as much leds as possible, and feed them with constant current led drivers. This ensures constant brightness and maximum electrical efficiency, as there is no need for ballast resistors. The easiest solution for this is probably to buy a commercial led strip, group together in series the links in the strip as much as possible, and feed this with an led driver…
In my opinion, though, I think it is way easier to buy a bunch of high power COB led chips, install each one of them on its own, adequately sized for its power heatsink, and feed each emitter with its own driver or multiple emitters with a single driver. This is easy to do, as for example a single 300mA current led driver rated for “36W” will output well above a hundred volts if enough led emitters in series are connected to it (30+), with no load output voltages dwelling way above that (a COB led chip is sort of and behaves like a bunch of leds in series, by the way). Others may think and believe differently, but if you know how to believe and what to do everything is safe despite of this.
Yes what I'm looking for is some led strips that have very high CRI...so far I haven't had a lot of luck in my search, and what I have found has been pretty low power and I'd need something like $3000+ USD worth of lights...I just know there's better options out there. I know this isn't going to be a <$1000 project but it seems a ripoff to pay $3000 for just the strips themselves.
The reason why I favor many strips over a smaller amount of COBs is because with strips the light would be spread more evenly, and if I needed to lower the light closer to the plants, with COBs that leads to much smaller regions that are really intense. With strips there's more light sources, more dispersed and this actually leads to a limit where the plants can get a lot closer and the light spread will still be even enough to not burn sections.
Also I may be wrong here but it seems that if I were to mount strips on aluminum channels or extrusions this would be sufficient for cooling. The COB style grow lights I've seen usually have either a compact fan powered heatsink or a very large passive heatsinks and I'm wanting to avoid that if possible.
When it comes to powering the lights that is an area where I need to do more research, I know it's probably pretty simple but I really don't want to mess that up and damage the chips. Dimming is more of a requirement than a "nice to have" feature.
But did you checked Juhong's lineup? The manufacturer sells small sunlight spectrum COBs too, with 5W and 10W rated power units. These you can run at rated current/power, or half of it for longer life. Could buy a bunch and install them on cheap as chips heatsinks like these, with just 5W or less per emitter your light will be quite evenly spread. The spectrum is also comparatively better to that of high CRI emitters designed for human visual usage.
cutter.au.com (@welight here) has quite a selection of what you want. Shipping isn't free, but he makes and delivers what's promised. These are not flexible rolls, but strips made on rigid al. There are many choices in high CRI. They have a Juki robot now for making this stuff look here "link to some LED strips":https://www.cutter.com.au/product-category/diy-led-kits/horticulture-lighting/grow-led-colors/linear-led-strip-boards/ There is a plethora of choices including Optisolis, cree, and Cutter branded red enhanced budget 98CRI. He has spectral graphs for some. Grow room PAR numbers for some, etc
[quote=DustinH]
Hey fellas!
I'm new to this forum, I actually stumbled across this place because of this thread.
I did see the beginning of the thread that has a chart with some high CRI chips, I was wondering if there's a list of available US bulbs for home use that have very high CRI, and also if if there's any strips(flex or rigid may both work) that utilize very high CRI chips.
I have a couple projects, one I'm just wanting to update my home lighting because I'm not satisfied with the CREE bulbs(although they are way better than the GE Reveal bulbs they replaced due to terrible lifespan).
The other project is what I need strips for, I want to experiment making my own grow light setup using very high CRI chips and compare that to a high grade LED grow light. Grow light manufacturers are obsessed with efficiency and quality definitely comes as a lower priority...this makes sense because most indoor growers are growing cannabis and being profitable is their main goal. I am going to be growing peppers and vegetables and I am more focused on light quality, I am thinking the closer I can get to mimicking the sun's spectrum the healthier and faster the plants will grow. I know the efficiency of the higher CRI LEDs that have a violet emitter and/or additional phosphors will obviously not be as good as the chips made for horticulture. I won't pretend I know much about this stuff yet, so if I'm mistaken please let me know.
Has anyone here done a similar project, or have any tips or products you would recommend?
I know I have a lot of learning to do, but I like the idea of that. This site has so much information it's hard to know where to get started!
Just remembered, and here they are (for DustinH and others interested):
This was claimed to be the spectrum graph for a 4000K 50W sunlight spectrum COB.
This was claimed to be the spectrum graph for a 5000K 50W sunlight spectrum COB.
As you can see these have both UV and infrarred emission, providing light which resembles natural light better than any other standard high CRI leds. As I said before, I found these buyer submitted spectrum graphs long ago in Juhong's store. Nothing else to say.
If anyone else has a collection of Hyperikon bulbs waiting to be sent for warranty, you may as well toss them. The company apparently ceased operations and had a clearance sale last year, then filed for bankruptcy in April.
Has anyone tried the Satco high CRI bulbs? They're fairly inexpensive but don't know how good they are. They run the whole gamut but here is a typical one we would buy.
There’s the GE “Filled With Sun” range that uses blue spike-less emitters. CRI is very high, but it isn’t as serviceable. I also don’t know what the flicker is like. The color temperature offerings are also really limited; 2700K and 5000K are the only two options.
Bocian makes bulbs that are just as good. He tended to prefer more efficient COBs that were still very high CRI but now he moved to Bridgelux Thrive which is the same class as sunlike.
His most powerful bulbs are 14W though, far less than that from Sunlike.
if you arent under the boot of a landleech, strips are best, since the led heat isn’t on driver.
I don’t think there is any way I can install such strips without getting a $500+ charge or pissing off the HUD inspector, gotta love entitled land leeches and the free mortgage they get.
We switched to mostly Satco in our office and they’re pretty solid. For these bulbs they are marginally better constructed than most of this style that are in stores, but they still fail and heat is the culprit most of the time. In an open air fixture it’s not a concern even if it’s dusty. We’ve usually had the higher wattage models in standard CRI but did have two of the high-CRI - unfortunately those were both in frosted glass fixtures so I can’t really comment on rendering. Those two eventually both died after I think 3-/2 and 4 years or thereabouts. We’ve used a lot more of their PAR track bulbs and those are ok, not stellar, but the price is right and the shortcomings aren’t really noticed by anyone other than a little glare in some locations.
They do stand behind their warranty, though, which is great. There’s no guarantee you’ll receive the same product as a replacement, however, since they have recently changed things up a bit…with the newer models they seem a little cheaper and they also dropped the max temp rating for some. But I wouldn’t hesitate to recommend any of their products. (come to think of it, I’ve also used a couple of their halogen tube shop light bulbs which were well made and lasted their rated time, and we did their higher wattage CFL bulbs for awhile, too, which were great, but we used more from TCP just based on supplier availability at the time.)
As Sleep Coach I’m new at this forum and interested in light systems which mimic the natural light during the day and seasons to calibrate the awake-sleep-rhythm on a daily basis. This to help my clients in their homes to reset their disturbed biological rhythm and improve their sleeping.
I noticed you interest is in the same area.
Ideally, I’m looking for a light being applicable for Europe for a reasonable price which includes a 10.000 lux full spectrum white light to wake people up and at lower lux being adjustable in full spectrum (smart) light in the range of 2700 K to 6500 K, including high score for the less familiar CRI, meaning R9, R12 etc.
Additionally, light that mimic campfire is of great important as this will allow the synthesis of melatonin when used during the night.
Looking at several fabricates I’m puzzled and have the impression that the adjustable colours look nice but miss the quality to mimic natural light in the full spectrum.
I realize I’m not a technician and probably expecting too much at this stage, but I’m interested in your thoughts and advice.
you might find useful products by searching for SAD Lights:
(Seasonally Affective Disorder)
here is one result:
please try to narrow your question down to a couple of choices, after you do your preliminary research
I will be curious to see what you find.
fwiw, Phillips Hue has the ability to turn on the lights on a schedule, at the color of your choice…
I used it to wake me up… I had Red light come on at a low level, then it would increase in brightness and get cooler 15 minutes later. 15 min after that the lights became bright and daylight white… Which consistently made me want to get out of bed.
I discarded the Hue because of excessive Flicker. I dont know if the newer models have less Flicker, but the system is feature rich and customizable. I dont know the R9 value… but I agree it is important… a lot of LEDs have poor R9…
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