CobKits
Well-Known Member
about 5-10 times longer than your CMH bulb
Led vs Cmh
- Thread starter Leandrobcool
- Start date
MeGaKiLlErMaN
Well-Known Member
CobKits
Well-Known Member
we would need to buy the chips first before its even a discussion. it took me months to get samples of the cxm27 and cxm32, and i certainly dont have vero or cree in 90 cri. would be at least a $500 investment in chips and a long time to get them, to see the exact same data
in a test like that we are really looking at the relative electrical efficiency of the different models, which brings up a point- this test should have a spectrum shot for every cob in it so we can crunch out QER
in a test like that we are really looking at the relative electrical efficiency of the different models, which brings up a point- this test should have a spectrum shot for every cob in it so we can crunch out QER
MeGaKiLlErMaN
Well-Known Member
Do you have the same data from. The ranges of 20-50W?
Leandrobcool
Active Member
Leandrobcool
Active Member
So it is a tight game between this two lights, but with a small advantage for the cob over the cmh, and personally I think I will take the cobs.
Thank u all for your time and your answers
Thank u all for your time and your answers
MeGaKiLlErMaN
Well-Known Member
better uMol/J is cobs 9/10times. Unless you run them hard. So that's why most prefer them. Pretty easy to get up to 2.2-2.5 if you have the coin
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CobKits
Well-Known Member
yes but measurement becomes less accurate at lower currents, theres some scatter
i try not to put too much stock in measurements below 20W, tho the sphere should do better here. i think on the free air measurements thats just reflected ambient light, etc. i could stand in a slightly different place and alter the par meter just from the light bouncing off of me. in any case they all seem to converge below 25W so in general, cheaper cobs= better cobs if youre going to run them soft. certainly zero support to the legend that certain chips outperform all others at low currents
Dreddd
Well-Known Member
i'm actually more interested in the 90CRI 3500k if possible..im doing some sphere work ill shoot one for you. i have 30/80 mounted, i have to get over my mounting issue to move faster with more tests. looks like im taking the grinder to the sphere to allow for full-size standard cooling options
btw do you happen to have a ModuLED Mega 13450-HBG with the connector set for sale maybe not on the site?
MeGaKiLlErMaN
Well-Known Member
What was the cri and spectrum of the cxm 22?
CobKits
Well-Known Member
maybe. i got some of these as samples, ill dig
Dreddd
Well-Known Member
If anyone's interested i called up the lovely people at Luminus and asked if they could provide me with the CXM-22 3500K 90 CRI spectrum, they were happy to help and provided me with an SPD file that i converted into a spectrum graph in excel.
I've studied this spectrum in comparison to the Citizen 3500K 90 CRI gen 6 and it actually looks better, i'm honestly surprised, it has the same amount of 455nm & 480nm but it peaks at 625nm while citizen peaks at 620nm, that make its 660nm output around 78% while the Citizen 660nm output is right on 70%.
Basically a better spectrum from what i can tell..
I've studied this spectrum in comparison to the Citizen 3500K 90 CRI gen 6 and it actually looks better, i'm honestly surprised, it has the same amount of 455nm & 480nm but it peaks at 625nm while citizen peaks at 620nm, that make its 660nm output around 78% while the Citizen 660nm output is right on 70%.
Basically a better spectrum from what i can tell..
TheChemist77
Well-Known Member
WHAT IS CRI? i was looking at a few different led's one sais 70 cri and one sais 80cri,, both come in 4000k or 3000k which should i get?
Dreddd
Well-Known Member
CRI is a measurement of how accurately a light source illuminates an object's true colors, the difference between 80 CRI & 90 CRI is basically how "wide" the spectrum is, how much of the visible light spectrum that the LED produces covers, usually the higher the CRI the more Red light is produced, its still not 100% clear if 90 CRI preforms better then 80 CRI with plants, but some interesting examples are making me lean towards 90 CRI, and i'd stay well away from 70, see "The Dawgs" thread: https://www.rollitup.org/t/dhp-presents-citizen-cob-1812-3500k-80cri-vs-1812-3500k-90-cri.932990/
MeGaKiLlErMaN
Well-Known Member
I'll do the tutorial on this one. Thanks!
Yodaweed
Well-Known Member
That's not entirely true, CRI (color rendering index ) show's how well a light can show colors of various objects (humans can see) through the light in comparison to how it looks in natural daylight, so natural daylight has a CRI of 100 , meaning you can see colors very well through it. It's more used for photography , it's not super important when it comes to growing canna as some of the best lights have a poor CRI. It's mostly important in photography and when you really need to see colors through the light.
"The color rendering index (CRI) of a light source is a quantitative measure of its ability to reproduce the colors of various objects faithfully in comparison with an ideal or natural light source. In general terms, CRI is a measure of a light source's ability to show object colors "realistically" or "naturally" compared to a familiar reference source, either incandescent light or daylight."
SOURCE: https://en.wikipedia.org/wiki/High_CRI_LED_lighting
frica
Well-Known Member
High CRI (2700-3500K) lights just tend to have more red (than similar Kelvin and 80 cri lights) and a peak close to 630nm.
That's why they're often preferred.
In the end it doesn't really matter that much.
Plants look nicer in high CRI light though, if you like to look at them.
Also easier to identify if something's wrong with your plant.
That's why they're often preferred.
In the end it doesn't really matter that much.
Plants look nicer in high CRI light though, if you like to look at them.
Also easier to identify if something's wrong with your plant.