COB efficiency Spreadsheets

salmonetin

salmonetin

Well-Known Member
wietefras said:
Those measurements are pretty much useless. I really don't get the point of these "black wall" PPFD measurements. Who has black walls in their grow room really?

I have grown with Gavita 1000W and it does produce a reasonably uniform 800umol/s/m2 over a 5x5 surface.

Lets stick to actual HPS figures like 1.7umol/s/W to 1.8umol/s/W measured in an Ulbricht sphere or 1.6umol/s/W in a proper grow tent on the canopy.
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...its your opinion... mine are totally diferent... those measurementes are really nice... radiometers give us the best measurements for growers...
...black walls are for test only the light of lamp... not the light reflected by walls... cell or other reflect part of tent... other lab testers dont take that in consideration... then her numbers are corrupted by reflected light of walls or ceiling... etc...



:peace:

Saludos...
 
wietefras

wietefras

Well-Known Member
No, it's a fact. People don't grow in rooms with light absorbing walls, so you don't need to take into consideration that you lose two thirds of the light if you would.

Seriously, the "cheap" led vendors already make "led" look ridiculous enough with their preposterous claims. Lets at least stick to the facts ourselves to present some semblance of a realistic comparison.

ps your keyboard is defective. There are dots all over your text.
 
P

PurpleBuz

Well-Known Member
wietefras said:
No, it's a fact. People don't grow in rooms with light absorbing walls, so you don't need to take into consideration that you lose two thirds of the light if you would
.
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the point of testing the light with non reflective sides is to show us how much light the light delivers to the canopy, and NOT to test the reflectivity of the walls or what ever tent a grower happens to be using. Without that its impossible to get a test for the light itself that is comparable with different mfg.
 
ttystikk

ttystikk

Well-Known Member
testiclees said:
Ya id give mine away to a local new grower


i paid ~400$ for it a few years ago. It grows decent flowers
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I ran mine over a 3x3 table full of youngsters and they grew okay, but seemed stressed. I then replaced it with one of my 4 x 54W COB LED modules and the plants went crazy. 550W did worse than 225W, seriously.
 
wietefras

wietefras

Well-Known Member
PurpleBuz said:
the point of testing the light with non reflective sides is to show us how much light the light delivers to the canopy, and NOT to test the reflectivity of the walls or what ever tent a grower happens to be using. Without that its impossible to get a test for the light itself that is comparable with different mfg.
Click to expand...
Ah, that must be why the industry standard for comparing light output is in an Ulbricht integration sphere. These are black on the inside right?

We're not talking about some random useless figure of a situation where only one third of the light is actually measured. The point is to replace an HPS fixture as used in an actual grow tent.
 
SaltyNuts

SaltyNuts

Well-Known Member
because people need to learn to appreciate good things
wietefras said:
Ah, that must be why the industry standard for comparing light output is in an Ulbricht integration sphere. These are black on the inside right?

We're not talking about some random useless figure of a situation where only one third of the light is actually measured. The point is to replace an HPS fixture as used in an actual grow tent.
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dude it's not like he made up that method, it's been used as a source of control data points for a long time. Yeah total light output is what's up, but differentiating measurement of direct light versus total light has utility, although it's more abstract.
 
ttystikk

ttystikk

Well-Known Member
SaltyNuts said:
because people need to learn to appreciate good things

dude it's not like he made up that method, it's been used as a source of control data points for a long time. Yeah total light output is what's up, but differentiating measurement of direct light versus total light has utility, although it's more abstract.
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Goniophotometry. It's a thing, a test and very good data to have on any given lighting system.
 
JorgeGonzales

JorgeGonzales

Well-Known Member
wietefras said:
Ah, that must be why the industry standard for comparing light output is in an Ulbricht integration sphere. These are black on the inside right?

We're not talking about some random useless figure of a situation where only one third of the light is actually measured. The point is to replace an HPS fixture as used in an actual grow tent.
Click to expand...
For somebody so familiar with industry standards, it's strange that you would mock an industry standard way of measuring PPFD.

You know what spheres and blacked out rooms have in common? They remove the environment as a variable.
 
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