Lighting one more quick ?

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What do the reflectors actually do? Concentrate the light more inward or spread it out more? I'm trying to come up with a configuration that will work in my 28" wide grow area. From reading on here I understand that one cob has a footprint of 16"x16". Thanks in advance. Pipes
 
Reflectors do just that, they reflect light. The cobs have a very wide angle of dispersion 100ish° commonly. A reflector depending on which one you use has a much steeper angle like 45°. The photons that would have going to the sides hit the reflector and depending on it's ior the photon looses some energy and bounces off into the new direction.

The footprint of a cob depends on the amount of light you put out. You can cover the same area with 10 15w cobs or a single 200 watt one. Something to note: drive cobs at ~65% their factory specs. that's the average sweetspot of heat to light output. So the CXM-32-40-70-54 i suggested in the other post I would drive at 2.25A and it would give me the same output as my current setup of 4 cobs makes.
 
Reflectors do just that, they reflect light. The cobs have a very wide angle of dispersion 100ish° commonly. A reflector depending on which one you use has a much steeper angle like 45°. The photons that would have going to the sides hit the reflector and depending on it's ior the photon looses some energy and bounces off into the new direction.

The footprint of a cob depends on the amount of light you put out. You can cover the same area with 10 15w cobs or a single 200 watt one. Something to note: drive cobs at ~65% their factory specs. that's the average sweetspot of heat to light output. So the CXM-32-40-70-54 i suggested in the other post I would drive at 2.25A and it would give me the same output as my current setup of 4 cobs makes.

Thanks for your input Druid. I appreciate any I can get. But your still talking over my head. A few days ago I knew absolutely nothing about this and I have no electrical background except basic household wiring, I have this week offd so I'm able to dedicate a few hrs a day to studying. So far besides here I'm viewing Growmau5's 1-7 video series on utube. I've put my brain into info overload several times so I just go back and review. I'm an old dog trying to learn a new trick. So far I have the frame design and layout. I plan on using citizen cobs-don't know which ones yet. I'm going to start with a six cob setup expandable to 8 cobs and passive heatsinks and am unsure on the size of them. I am planning on using a MW driver and I still have questions I have to answer on which one to select. It has to run 6-8 cobcs efficiently. I'm using cobkits and grow northern mostly as sources. Thanks to you and BigSmO for all the advice so far:thumbsup:Pipes
 
@Druid please take this as a compliment. You are a very very intelligent person when it comes to lighting but please try not to let your intelligence scare people away. Knowing how to teach or help is the hardest part. If I get stumped I'm running to you lol.


Basically cobs have a wide beam they cast. Reflectors reflect that light at its closest point (the reflector) vs reflecting it on the walls of your tent. It's debatable and I feel subject to everyone's space differently.

Personally I feel if your in a small space with plenty of light to go bare or to use a holder like the bjb which has a small mini reflector built in. If your in a larger space with less plants the need to focus the light increases. You could always buy them and test them out to make your own judgement. Most smart phones have a lux meter app. You could place the phone on the floor a foot away from the plants and get readings with and without optics.
 
@Druid please take this as a compliment. You are a very very intelligent person when it comes to lighting but please try not to let your intelligence scare people away. Knowing how to teach or help is the hardest part. If I get stumped I'm running to you lol.


Basically cobs have a wide beam they cast. Reflectors reflect that light at its closest point (the reflector) vs reflecting it on the walls of your tent. It's debatable and I feel subject to everyone's space differently.

Personally I feel if your in a small space with plenty of light to go bare or to use a holder like the bjb which has a small mini reflector built in. If your in a larger space with less plants the need to focus the light increases. You could always buy them and test them out to make your own judgement. Most smart phones have a lux meter app. You could place the phone on the floor a foot away from the plants and get readings with and without optics.

Oh no building your own light is as easy as legos. If you have something to make holes in metal you can even build a frame with ease.

Think of photons like billiard balls. They are shot off from the light at very wide angles. About as wide as a human's field of vision. So when you take the place of a cob with your eye everything you can see in your periphery will get photons. Hold a toilet paper roll in front of your eyes and you have a reflector. The photons that would have shot out to the far sides are now bouncing off the tube (like a billiard ball of the sides) and then down on towards the plants.
Seing is the opposite of lighting something. The photons bounce off of something and into your eye. When you light something it's just the other way around.
Now that we've drawn that parallel we immediately have to think of glasses. Of course there are glasses for lights too. Those are called optics/lenses and they redirect the photons as they travel through the glass instead of having them bounce off. The unfortunate thing about that is that when a photon travels though glass it looses energy for every bit it travels. So the photons that would have gone straight down and never hit a reflector are now also less energetic.
If you plan to use lenses you should go with glass. There are also big silicon lenses that give a very even spread(good for a cog) but they are quite thick and dim the light considerably(wouldn't use them if you don't have crazy bright lights).
 
I have absolutely no issues with building the frame and wiring. I'm a very much a diy person. I've built houses, decks, canoes and other boats, motorcycle engines, reload my own ammo and cast my own bullets, grow my own pot and so forth. Choosing the correct components is the issue but that will come. When I come up with the list I'll post it here and then ask for opinions and recommendations. I'm harvesting a crop today and starting another one this week. When that grow is done is when I want my cob system up and running. So there is really no big hurry but any input you and BigSmo and others want to give will be greatly appreciated. Pipes
 
Here's an idea
you give me the exact dimensions of your grow-space and I render a few possible solutions
As I mentioned in my first post my grow area is 28"x60" and typically I only grow 3 plants at a time. I plan on running 2 rows of 3 cobs each running lengthwise in the closet. So each plant will have 2 cobs above it. This is what I'm coming up with so far:
1 MW HLG-240H-C1050 Driver
6 CLU48-1212 90CRI 3500K COB's
6 Ideal holders
6 120mm Passive pin heat sinks


I know there are other odds and ends to get but will this driver operate the 6 cob's and maybe later add 2 more? Also I'm finding that component availability might also be a problem. Anything you come up with will be very welcome indeed! If I don't get back soon its because now I have to clean pot. Pipes
 
As I mentioned in my first post my grow area is 28"x60" and typically I only grow 3 plants at a time. I plan on running 2 rows of 3 cobs each running lengthwise in the closet. So each plant will have 2 cobs above it. This is what I'm coming up with so far:
1 MW HLG-240H-C1050 Driver
6 CLU48-1212 90CRI 3500K COB's
6 Ideal holders
6 120mm Passive pin heat sinks


I know there are other odds and ends to get but will this driver operate the 6 cob's and maybe later add 2 more? Also I'm finding that component availability might also be a problem. Anything you come up with will be very welcome indeed! If I don't get back soon its because now I have to clean pot. Pipes
I'd also need the height.

Yeah that driver can run 6 cobs.
 
That's going to be a kick ass light for that space. 300w of cobs is like 750w of blurple. Then add in advertising claims your close to a eBay 2000w light lol. The driver is rated for 238v and your running 36v cobs so it can handle 6.5 cobs. Future upgrading or addition isn't possible.
 
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