Par Multiplier Thread

wietefras

Well-Known Member
OK, guess I remembered wrong, but please standardize the other way around and not on a heap of decimals with leading zeroes.
 

wietefras

Well-Known Member
Guess it's what you're used to. I find it easier to remember 69 ;)

To be honest if you use anything between 65 and 70 you're probably within the variation of what you can expect from a COB anyway. Cree mentions a possible 7% deviation and then there is the bins which can be 10% "wide".

Found some lists of QERs from Alesh, probably the first with PAR only and the second with all photons counted:
downloadfile-1.jpeg

Alesh qer.jpg
 

wietefras

Well-Known Member
I think it was Jorge who posted the sheets for Citizen with LER and QER (1212, 1812, 1818 and 1825):
Citizen LER QER PAR to lm
2700K 80CRI 329 4,92 66,9
3000K 80CRI 328 4,86 67,5
3500K 80CRI 335 4,81 69,6
4000K 80CRI 338 4,75 71,2
2700K 90CRI 284 4,97 57,1
3000K 90CRI 276 5,04 54,8
3500K 90CRI 283 4,92 57,5
4000K 90CRI 293 4,81 60,9
 

wietefras

Well-Known Member
Also found some measurements that Malocan took with his spectrometer:
Code:
COB                             PPFD        lux       ppf-lm    CCT
CXB3590-3500K-80CRI 49W         605,7      42.850      70,7     3379K
CXB3590-3500K-80CRI 49W         404,9      28.540      70,5     3484K
CXB3590-3500K-80CRI 85W         642,5      45.340      70,6     3488K
CXB3590-3500K-80CRI 106W        219,7      15.500      70,6     3498K
CLU058-1825-2700K-90CRI 49W     437,3      26.530      60,7     2856K
CLU058-1825-2700K-90CRI 85W     673,1      40.990      60,9     2876K
CLU058-1825-2700K-90CRI 106W    229,7      14.020      61,0     2879K
CLU058-1825-2700K-90CRI       2.454,0     148.100      60,4     2819K
 

wietefras

Well-Known Member
Well it's basically the same thing: multiplier=1/divider or divider=1/multiplier. So it's not an issue to have both in an Excel sheet. Or people can do the math themselves, of course but I personally find it easier remembering 69 instead of 0,014493 or 67 instead of 0,014925.
 

greg nr

Well-Known Member
This is interesting. I'm running an xm-l2 bar with 12 led's and currently have it about 2 feet above my veg. It is reading 8000 lux at the soil level. I can easily get 10k if I drop the lights to 12".

So my xm-l2 bar is equal to a cree cob? It's drawing 62 watts so it has the same wall draw. But damn, I didn't think it was that bright.
 

Stephenj37826

Well-Known Member
This is interesting. I'm running an xm-l2 bar with 12 led's and currently have it about 2 feet above my veg. It is reading 8000 lux at the soil level. I can easily get 10k if I drop the lights to 12".

So my xm-l2 bar is equal to a cree cob? It's drawing 62 watts so it has the same wall draw. But damn, I didn't think it was that bright.
Most cob fixtures are around 30k-40k @ around 30-40 watts per square foot
 

Shugglet

Well-Known Member
By fixture, do you mean multi-cob arrays or single cob on a heatsink? If it's multi-cob, it;s not really a fair comparrison, no?
It has the same 62 watt wall draw as what now? Which cob fixture you referring to?

Also, why would it be unfair to compare a mutlipoint light source to another multipoint light source. Also, 10k lux is not a lot of light...
 

greg nr

Well-Known Member
It's not meant to be a lot of light. It is a supplement/early veg light. I was just surprised it as a unit was on par with a single cob. I wan't expecting that.

If you want a comparison, then its to a single cob drawing ~60w. Why would I compare a 60w fixture to a 300w fixture? I don't sell led's. :lol:
 

Stephenj37826

Well-Known Member
It's not meant to be a lot of light. It is a supplement/early veg light. I was just surprised it as a unit was on par with a single cob. I wan't expecting that.

If you want a comparison, then its to a single cob drawing ~60w. Why would I compare a 60w fixture to a 300w fixture? I don't sell led's. :lol:
I gave a fair comparison in watts per sq ft. I wasn't really insinuating anything honestly. XML2s are fine...... COBS aren't the end all be all by any means. I was just saying 10k lux is ~ 120-150 ppf depending on spectrum.
 

DankaDank

Well-Known Member
It would be nice to get some relatively accurate LER's and QER's for the gen 7 VERO's but the SPD's are shitty and I have seen substantial variances in the multipliers from different calculations.
 

Shugglet

Well-Known Member
It would be nice to get some relatively accurate LER's and QER's for the gen 7 VERO's but the SPD's are shitty and I have seen substantial variances in the multipliers from different calculations.
What kind of multipliers we talking? I'm using .015 to guesstimate my setup using a mix of 3500k cri80 and 3000k cri90 vero 29B SE chips. Regardless it should get me in the ballpark.
 
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