mahiluana
Well-Known Member
not at all. - I just laughed and like the zestful definition of twostrokenut to see my own lifes`creativity finding my way.
New light or????
- Thread starter Gorillaglue4u
- Start date
nfhiggs
Well-Known Member
Rayleigh scattering is responsible for the blue sky.
Olive Drab Green
Well-Known Member
Actually, it’s because God loves the Infantry.
nfhiggs
Well-Known Member
I did some artwork that may help to "shed some light on the subject" of shedding light on the subject...
Maybe these will help illustrate the fallacy of "light intensity = penetration". First up is an image of our hypothetical 200W single light source (a COB if you like) shining down into a 4x4 grow space (4 feet high). It has a perfect optic that focuses the light into a uniform cone and produces 1000 uMols PPFD at 2 feet down:
The yellow area shows our effective "grow space" The area outside of that has no light (its outside the cone) or is too intense. We get good "penetration" for about 2 feet, but we are really only able to utilize about 1/3 of our space effectively. Now lets examine a two 100W light configuration:
The numbers to the right of the box are the individual uMol levels of one of our 100W emitters. The large shaded triangle area shows where the light cones overlap each other and doubles the light falling on that area. The two shaded triangles in the bottom corners are what we get with perfect reflective walls.
OK, that increases the effective grow area (to about half), but now we have uniformity issues - a nice fat "hot spot" in the center. This is what a lot of commercial grow lights actually produce. Spreading the lights further apart is the usual solution. Lets look at adding more sources instead - four of them in all:
Hey, now it looks like we are getting somewhere! The light gray area have two light cones hitting them, the dark gray areas have three light cones hitting them, and the brown area at the floor sees light from all four emitters. AND, we have eliminated that pesky "hot spot" in the center. We have increased our effective grow area to 3/4 of the space, while maintaining the exact same light levels at the floor. This is actually what a lot of DIY COB growers do - one COB per square foot covering the entire space.
OK, so what if we keep going?
Here is what it looks like with 8 emitters at 25W each, spaced 6 inches apart:
And we increase the usable space at the top even more, while maintaining the same light levels at the bottom. As you can see, its a mathematical progression. Every time you double the emitters and halve the power, you reduce the intensity at the very top (where its too high to use anyway) while maintaining it at the lower levels. The natural end of the progression is a uniform illumination from top to bottom - just like the sun gives us, but achieved in a different way.
This is why strips work so well - as long you are putting the same amount of light into the space, the "penetration" does not really change when you spread it out over multiple emitters, but your "usable space" increases as the plants can grow closer to the light source without damage - your effective "penetration" actually INCREASES. We went from 24" minimum hang height of the single emitter, resulting in 24 inches of penetration to 8" of hang height with the 8 emitters, resulting in 40 inches of penetration.
Of course I do realize this is hypothetical "perfect" conditions. In reality walls are not perfectly reflective, and optics do not give us perfect light cones, but the reasoning and the physics is sound.
Maybe these will help illustrate the fallacy of "light intensity = penetration". First up is an image of our hypothetical 200W single light source (a COB if you like) shining down into a 4x4 grow space (4 feet high). It has a perfect optic that focuses the light into a uniform cone and produces 1000 uMols PPFD at 2 feet down:
The yellow area shows our effective "grow space" The area outside of that has no light (its outside the cone) or is too intense. We get good "penetration" for about 2 feet, but we are really only able to utilize about 1/3 of our space effectively. Now lets examine a two 100W light configuration:
The numbers to the right of the box are the individual uMol levels of one of our 100W emitters. The large shaded triangle area shows where the light cones overlap each other and doubles the light falling on that area. The two shaded triangles in the bottom corners are what we get with perfect reflective walls.
OK, that increases the effective grow area (to about half), but now we have uniformity issues - a nice fat "hot spot" in the center. This is what a lot of commercial grow lights actually produce. Spreading the lights further apart is the usual solution. Lets look at adding more sources instead - four of them in all:
Hey, now it looks like we are getting somewhere! The light gray area have two light cones hitting them, the dark gray areas have three light cones hitting them, and the brown area at the floor sees light from all four emitters. AND, we have eliminated that pesky "hot spot" in the center. We have increased our effective grow area to 3/4 of the space, while maintaining the exact same light levels at the floor. This is actually what a lot of DIY COB growers do - one COB per square foot covering the entire space.
OK, so what if we keep going?
Here is what it looks like with 8 emitters at 25W each, spaced 6 inches apart:
And we increase the usable space at the top even more, while maintaining the same light levels at the bottom. As you can see, its a mathematical progression. Every time you double the emitters and halve the power, you reduce the intensity at the very top (where its too high to use anyway) while maintaining it at the lower levels. The natural end of the progression is a uniform illumination from top to bottom - just like the sun gives us, but achieved in a different way.
This is why strips work so well - as long you are putting the same amount of light into the space, the "penetration" does not really change when you spread it out over multiple emitters, but your "usable space" increases as the plants can grow closer to the light source without damage - your effective "penetration" actually INCREASES. We went from 24" minimum hang height of the single emitter, resulting in 24 inches of penetration to 8" of hang height with the 8 emitters, resulting in 40 inches of penetration.
Of course I do realize this is hypothetical "perfect" conditions. In reality walls are not perfectly reflective, and optics do not give us perfect light cones, but the reasoning and the physics is sound.
Chip Green
Well-Known Member
(uncomfortable, lengthy applause)
Olive Drab Green
Well-Known Member
What he said.
Randomblame
Well-Known Member
Really..?!I can’t give you anything different when I’m being pointlessly harassed. Of course I’m not going to have anything serious to say when I cannot take you seriously, That said, I’m not here to entertain you. Go fuck yourself.
You will not be bothered useless! If you tell garbage, you have to expect to be corrected. And to stay true, you were the first one who reacted like a injured tiger. Once someone corrects you or claims that you are wrong, you react with insults because you have no arguments. That's your problem!
You take every correction as an attack on your person! But nobody attacks you, just shows you your wrong reasoning. One page back you wanted my advice, now I should fuck myself, just because I have criticized your (and other) dirty language.
You are certainly one of those who strikes first and then asks. Maybe you should not have gone to the army, but in a behavioral therapy ...
I'm just trying to help you understand how penetration really works and if you would kept your mind open instead of defending your wrong conclusions like a lion, then the discussion would be over since a few days and you would already have some efficient strips on your shopping list.
Randomblame
Well-Known Member
Some posts really deserves a "double like", this is for sure one of them !!!
nfhiggs
Well-Known Member
Thanks Random, you're one of the people here whose opinion I respect.
I was up half the night making those images.
Randomblame
Well-Known Member
I can only give that back, mate! Your contributions here are always remarkable.
Just a pity that the world is soooo big .. If I were to organize a meeting of qualified LED buddies, you would certainly be right on the top of the list! Keep up the good work...!
Great but what about par / ppfd readings....a foot more than enough ?
Randomblame
Well-Known Member
What do you mean? PAR/PPFD readings under the sun? Try it with a free smartphone lux meter app. It does almost the same and you can convert the reading into PPFD by dividing it by 69. When you stand in the blazing sun and there is no shade and you measure on the ground and in 4ft. height you will see almost identical values.
If you ask for the needed heights inside a tent a good rule of thumb is to use the distance between the COB's/strips.
With evenly spaced EB strips the plant could touch the diodes without damage because of the low current one diode gets. 10" should be enough to get good penetration down to the lowest branches. The more strips you use the deeper the light can penetrate.
If you ask for the needed heights inside a tent a good rule of thumb is to use the distance between the COB's/strips.
With evenly spaced EB strips the plant could touch the diodes without damage because of the low current one diode gets. 10" should be enough to get good penetration down to the lowest branches. The more strips you use the deeper the light can penetrate.
mahiluana
Well-Known Member
great brother - "artwork" (KWh) is spending the time in an advanced movement powered and multiplicated with the kiloponds of your effort 
as good artpieces often influates other artist creactivity - i want to tell you, that looking to your pics it´s notable that:
in a sqare grow as you discribed it, you normally grow 1/4/9/16/25/...... plants, as long as their morphologie (shadow) is ~ like a circle. --- many growers intuitivly hang their light source on top of the axis of the plant stem.
i think that`s the wrong position of a light source...because most
of led chips have a much wider beam angle as it is illustrated in your drawings.
(Lenses and reflectors decrease light ~3 -10% ... and i`m not a great fan.)
@ ~120-140° beam angle your led still produce 50% of the centers` flux.
so it is just obvious,...
- if you work with cobs, that you better hang them inbetween 2 or 4 plants.
- if you scrog or sog to minimize the depth of needed penetration and maximize your yield
- you can`t get better coverage (less shadows) than i.e. with 32 boards like this (26x13cm) / sqm. and drive them @ ~ only 5mA / each led / close to touch the plants
With costs of only 5$ / board you can open the sky to your babies and light them up with 12800 cold stars at low cost, high lumens and longlife.
With limited headspace your light can be as close as 3mm from the ceiling.
Sanitas Vibrationum
Active Member
Sammy f-series gen3 > EB gen 2.
Gorillaglue4u
Well-Known Member
Guy on Craigslist Is selling a light he built for 500 bucks this is what the ad says
10 cxb 3590's 5000k with 2 meanwell hlg 240's and an analog dimmer.
I talked to him and he said it's on a 4x4 frame. My question is can I get more bang for my buck by ordering and building my self. Or will that light do well in my 4x4 flower room?
10 cxb 3590's 5000k with 2 meanwell hlg 240's and an analog dimmer.
I talked to him and he said it's on a 4x4 frame. My question is can I get more bang for my buck by ordering and building my self. Or will that light do well in my 4x4 flower room?
Randomblame
Well-Known Member
That light will do the job for sure, althrough the 5000°k spectrum is not perfect for flowering.
With 500$ you could buy 14x 4ft. EBgen2 strips in 3500°k and a pair HLG-320H-C1050B's. Thats ~700w from the wall if you want and still more efficient as the coolwhite COB's. ~170lm/w or ~2,5μMol/J.
Gorillaglue4u
Well-Known Member
What site do you recommend ordering from? I'm gonna place a order today. I was gonna go threw one and got to the end and they wanted 75 bucks for shipping of cobs.
Randomblame
Well-Known Member
Digikey or Arrow! They both offer free shipping above 50 or 100$.
Search by part-number. 4ft EBgen.2 in 3500°k is:
BXEB-L1120Z-35E4000-C-B3
That's the digikey link:
https://www.digikey.de/product-detail/en/bridgelux/BXEB-L1120Z-35E4000-C-B3/976-1732-ND/7907661
You can order them immediately, even if they are not in stock. They regularly get new ones!
Arrow has 4ft. strips in 3500°k in stock, but only 13:
https://www.arrow.com/de-de/products/bxeb-l1120z-35e4000-c-b3/bridgeluxbridgelux
But you take twice as much 2footers(28pcs)
https://www.arrow.com/de-de/products/bxeb-l0560z-35e2000-c-b3/bridgelux
Thats the HLG-320H-C1050B:
https://www.mouser.com/ProductDetail/MEAN-WELL/HLG-320H-C1050B/?qs=/ha2pyFaduhb02XRVrmT0pPRWrAGjNPDaGqXbJv9uF8J1epMeMly8bHg/gpcu%2bUz9FhD4wkX3c4=
For wiring examples and other useful tips+tricks visit ledgardeners website:
http://ledgardener.com/
Search by part-number. 4ft EBgen.2 in 3500°k is:
BXEB-L1120Z-35E4000-C-B3
That's the digikey link:
https://www.digikey.de/product-detail/en/bridgelux/BXEB-L1120Z-35E4000-C-B3/976-1732-ND/7907661
You can order them immediately, even if they are not in stock. They regularly get new ones!
Arrow has 4ft. strips in 3500°k in stock, but only 13:
https://www.arrow.com/de-de/products/bxeb-l1120z-35e4000-c-b3/bridgeluxbridgelux
But you take twice as much 2footers(28pcs)
https://www.arrow.com/de-de/products/bxeb-l0560z-35e2000-c-b3/bridgelux
Thats the HLG-320H-C1050B:
https://www.mouser.com/ProductDetail/MEAN-WELL/HLG-320H-C1050B/?qs=/ha2pyFaduhb02XRVrmT0pPRWrAGjNPDaGqXbJv9uF8J1epMeMly8bHg/gpcu%2bUz9FhD4wkX3c4=
For wiring examples and other useful tips+tricks visit ledgardeners website:
http://ledgardener.com/
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