CRI test and Mcree weighted results

[SSGrower]

Even with the lowest step chromatic bins there is variation so yeah I ding think about spectrum one bit when deciding drive current.

That's fine and I'm not saying there is for most people, I just have an unhealthy curriosity.

 

[Rayne]

Thanks for the honest answer, stick with me here because I'm an every little bit helps kind of thinker....

The spectral distribution has the potential to change, there are many combinations of various light colors (combinations of monochromatic light) that will result in the same color temperature.

Now the question... what is happening when additional current is applied? I believe it pulls up the peaks of the spectral distribution.

Why would this be relevant? .... The photons we are looking for reside on the slopes of this distribution and where they are will determine the degree to which they are increased. If we were lucky or good we would be able to selectively increase those wavelengths.

When the overall current is increased the relative intensity of a specific par spectrum color goes up. If the overall current is decreased the relative intensity of a specific color goes down.

When the appropriate testing equipment is set to detect just 450nm it will give the read out for just 450nm, regardless of how much current is used during the pulse test.

The peaks with the highest intensity shift relative to the color rendering index of a COB diode. If my understanding is correct the phosphor coating on a COB is where the CRI changes.

In addition to your chosen, COB and without having to increase the overall amperage. If you want to add more intensity to a specific wavelength just add monochromatic diodes to your LED array.

Here are links to previously posted spectrum graphs:
CLU058-1825 70 CRI
CLU058-1825 80 CRI
CLU058-1825 90 CRI

Just in case: Here are the Citizen CLU058-1825 data sheets.
70 and 80 CRI
90 CRI

 

[PhotonFUD]

Following up on Rayne's last post, if lower current causes a SPD shift to the right resulting in more photons over 600nm (as a % or even a total) that would be another reason to under drive chips.

 

[CobKits]

i should have the sphere end of next week it will be a little while before i can get calibrated quantitative data out of it but once i mount a chip in there i should be able to take repeatable spectrums all day long.

should be easy to see an effect with just a few data points like 300, 1000, 2000, and 3000 mA and we can use that as a starting point for future study if warranted

 

[DrBlaze]

Fortunately this Mcree comparison is only stage 1 of this project. We'll eventually have some real world results under the test lamps to compare with the numbers

Yes, well 5 way grow off. Results will be in early next year.

So any updates on this for us? Is there a phase 2 planned (or even underway)?

Thank you btw for the work you put into this.

 

[Rahz]

They are still in flower. FWIW there's no visible difference in flower production and all the samples are doing very well.

This was taken at flip. You can see both high CRI samples stretched. Not a lot of difference between the other three.

 

[DrBlaze]

They are still in flower. FWIW there's no visible difference in flower production and all the samples are doing very well.

This was taken at flip. You can see both high CRI samples stretched. Not a lot of difference between the other three.

View attachment 3857655

I love that there's a 3000k 70, 80, and 90 cri in this. You can certainly see the extra stretch in the 90.

 

[cdgmoney250]

It could just be the reflection of lower quality spectrum, but the 90 CRI test plants seem a little darker green and lush, as well as larger.

 

[DrBlaze]

It could just be the reflection of lower quality spectrum, but the 90 CRI test plants seem a little darker green and lush, as well as larger.

Now that I look closer, I think you're right, it appears that the high cri canopies are thicker (not just seeing increased inter-nodal spacing). Also the 3500k appears to have wider leaves than the rest. We need higher resolution.

@Rahz, I hate to be a PITA, but at some point could you take a separate higher resolution shot of each of the 5 canopies, and from the same height/angle for each? This is the first test of this kind that I've seen anywhere, and I'm very interested

 

[ttystikk]

They are still in flower. FWIW there's no visible difference in flower production and all the samples are doing very well.

This was taken at flip. You can see both high CRI samples stretched. Not a lot of difference between the other three.

View attachment 3857655

Thanks again for this, the growing community will owe you a debt of thanks for a long time.

 

[Rahz]

I will ask for more pics. There are already some branch shots in the works during harvest. Inter-nodal spacing is visibly longer in the two 90CRI samples. We've talked about the differences and one things that came up was that the 3000/70 looked more yellow/green than the other samples. I had him switch the lamps around and the yellow tinge followed the lamp, so the color of the light does affect the color of the plants.

 

[BuddyColas]

They are still in flower. FWIW there's no visible difference in flower production and all the samples are doing very well.

This was taken at flip. You can see both high CRI samples stretched. Not a lot of difference between the other three.

View attachment 3857655

They are still in flower. FWIW there's no visible difference in flower production and all the samples are doing very well.

This was taken at flip. You can see both high CRI samples stretched. Not a lot of difference between the other three.

View attachment 3857655

I do not have a doctorate degree in horticulture, but it sure looks like more growth (photosynthesis) going on with the 90 cri lamps for sure. Great side-by-side pics. It makes me wonder, are there more bud sites with the 90 vs the 80? And are the flowers bigger? I guess that will all wash out with harvest weight. Thanks for doing a great thread.

 

[MeGaKiLlErMaN]

2700 and the 3000k 90s look the best so far... Love the grow! This will make a good referance point for everyone. 2700K is my favorite in this match up. But I would love to be wrong as well

 

[ttystikk]

2700 and the 3000k 90s look the best so far... Love the grow! This will make a good referance point for everyone. 2700K is my favorite in this match up. But I would love to be wrong as well

About the time this test wraps up I'll be in the market for some chips, making this a very handy reference for choosing exactly which ones to get.

 

[MeGaKiLlErMaN]

About the time this test wraps up I'll be in the market for some chips, making this a very handy reference for choosing exactly which ones to get.

Same here man it will be a good time, I'm going my 150sq/ft flower room to the 9s

 

[hillbill]

The results of every light in the test seem great. White COBs will get the job done with minor differences. There are times when some stretch is nice for training which is all I do. The better COBs are within a few percentage points of each other and by far the best light sources for tent types.

Watching out for quantum boards though.

 

[wietefras]

Nice test!

If you're interested in the leaf color, then maybe once take the picture of all tents with a camera flash instead of with the COBs switched on. Or take a leaf from each tent and put them all in one photo together.

It's always difficult to get the green to show accurately though. Make the picture a tad brighter and the green color can already change a lot.

 

[MeGaKiLlErMaN]

@Rahz you good? I feel like a crack head looking for the results.

 

[Rahz]

They are getting close. The high CRIs and the 3000/80 are finishing first, closely followed by 3500/80. The 3000/70 is maybe 5-6 days behind. It will all be coming down within the next week.

 

[ttystikk]

They are getting close. The high CRIs and the 3000/80 are finishing first, closely followed by 3500/80. The 3000/70 is maybe 5-6 days behind. It will all be coming down within the next week.

Very nice! Hope to see some pics soon.