Lighting Light height: Coverage vs Intensity question

[lunarman]

@BigSm0 and AFNers with the brilliant autcobs.

Lets say you have plants 20 inches in diameter and a level canopy. What height would you put the autocobs so that you get ideal intensity (low) and at the same time great canopy coverage (high)? It would be cool if there was a math formula for this, or some sort of visual test you can do. Or if nothing else then how to use your intuition.

 

[Flash]

@BigSm0 and AFNers with the brilliant autcobs.

Lets say you have plants 20 inches in diameter and a level canopy. What height would you put the autocobs so that you get ideal intensity (low) and at the same time great canopy coverage (high)? It would be cool if there was a math formula for this, or some sort of visual test you can do. Or if nothing else then how to use your intuition.

if it was me about 30inches or more away. You’d really have to look as you physically adjusted the smocob and the whats hitting the plant. Math formula hahaha over thinking it. Just grow and experiement buddy you dont wanna over think it ya know. Ill agree a formula could make it easy but then thats the fun of growing! It’s what seperates good growers from the bad ones, experience is nice to have and i am def getting my fair share of it!

 

[HemiSync]

if it was me about 30inches or more away. You’d really have to look as you physically adjusted the smocob and the whats hitting the plant. Math formula hahaha over thinking it. Just grow and experiement buddy you dont wanna over think it ya know. Ill agree a formula could make it easy but then thats the fun of growing! It’s what seperates good growers from the bad ones, experience is nice to have and i am def getting my fair share of it!

And it’s going to be strain specific as well. Some will take a more intense light while others will taco and start showing deficiencies. As far as science goes, I do believe @BigSm0 mentions somewhere that at 24 inches the light is saturating a 2x2 area. I have been keeping my lights at 30+ inches with four of them and only as they enter their flowering stretch do I allow them to get closer. I’m still playing with it but it’s going to require one to be able to read their plants with this new problem these COBs are creating, high light intensity without the heat issues you would normally see when getting a light too close.

A cheap piece of tech that might give one a better understanding of the lights intensity and dispersal is a lux meter. I pulled mine out and the amount of light in my tent is amazing.

 

[lunarman]

I thought @BigSm0 was at 8 inches above now with the Green Leaf Mega Crop nutes somehow making it easier to get closer. 30 inches away seems quite far away to me. It would give good coverage but it would not have the intensity of being lets say 12 inches away.

I have been adjusting my lights and just looking at the light intensity on the leaves as I move the lights up and down. Trying to watch the leaves and how bright they get as I move closer and watching the outer canopy edge as well to see if its getting light coverage. That is my technique right now but was hoping for some insight on a better way to do it.

I have had my lights 8-10 inches away for days on end and I have never seen any tacoing. But I keep wondering if the daily light integral is too high for the plants and even though I can't see any issues, there could be issues hidden that I just can't see.

@HemiSync I have a lux meter. I stopped using it once I switched from HPS to COB. How would you use a lux meter for what I am trying to work on with the cob's and coverage and intensity?

 

[HemiSync]

I thought @BigSm0 was at 8 inches above now with the Green Leaf Mega Crop nutes somehow making it easier to get closer. 30 inches away seems quite far away to me. It would give good coverage but it would not have the intensity of being lets say 12 inches away.

I have been adjusting my lights and just looking at the light intensity on the leaves as I move the lights up and down. Trying to watch the leaves and how bright they get as I move closer and watching the outer canopy edge as well to see if its getting light coverage. That is my technique right now but was hoping for some insight on a better way to do it.

I have had my lights 8-10 inches away for days on end and I have never seen any tacoing. But I keep wondering if the daily light integral is too high for the plants and even though I can't see any issues, there could be issues hidden that I just can't see.

@HemiSync I have a lux meter. I stopped using it once I switched from HPS to COB. How would you use a lux meter for what I am trying to work on with the cob's and coverage and intensity?

The lux meter will still be measuring the intensity of the lights regardless if it is HPS or COB. For example my lights are current 24-28 inches from my canopy and my lux meter tells me that at 24 inches I’m getting 24000 lux at the canopy. If you started tracking this and how much each strain can take you might have a better idea how you could work those numbers into what you are doing.

As far as closeness goes, I had mine at 24 inches above canopy when I first started this SCROG thinking she’s an older mother plant and she could take it. Big mistake, within just a few days I was showing symptoms of calcium, magnesium, and manganese deficiencies starting to spread quickly thru her leaf structure. I move the lights to 32 inches and added a little more nutrients and her growth has recovered very quickly.

I think if you let the plants grow into the light, they can withstand a lot more. I also think they need it further away in veg than in flower. My last grow I had one light eight inches from one of the gals’ colas with no sign of problems. And my current SCROG has already grown back to within 25 inches and does not seem to be minding it.

 

[lunarman]

The lux meter will still be measuring the intensity of the lights regardless if it is HPS or COB. For example my lights are current 24-28 inches from my canopy and my lux meter tells me that at 24 inches I’m getting 24000 lux at the canopy. If you started tracking this and how much each strain can take you might have a better idea how you could work those numbers into what you are doing.

As far as closeness goes, I had mine at 24 inches above canopy when I first started this SCROG thinking she’s an older mother plant and she could take it. Big mistake, within just a few days I was showing symptoms of calcium, magnesium, and manganese deficiencies starting to spread quickly thru her leaf structure. I move the lights to 32 inches and added a little more nutrients and her growth has recovered very quickly.

I think if you let the plants grow into the light, they can withstand a lot more. I also think they need it further away in veg than in flower. My last grow I had one light eight inches from one of the gals’ colas with no sign of problems. And my current SCROG has already grown back to within 25 inches and does not seem to be minding it.

I'll bring out the light meter I have again and dust it off and take some readings. And continue this never ending adventure with light intensity, fixture height and the coverage. And continue to learn reading the plants.

 

[HemiSync]

I'll bring out the light meter I have again and dust it off and take some readings. And continue this never ending adventure with light intensity, fixture height and the coverage. And continue to learn reading the plants.

We are just going to have to remember, we are on the cutting edge of tech here and there might be a learning curve.

 

[BII]

@BigSm0 and AFNers with the brilliant autcobs.

Lets say you have plants 20 inches in diameter and a level canopy. What height would you put the autocobs so that you get ideal intensity (low) and at the same time great canopy coverage (high)? It would be cool if there was a math formula for this, or some sort of visual test you can do. Or if nothing else then how to use your intuition.

If you could define "great canopy coverage" in terms of the physical variables involved, such a maximal PAR distribution over the entire area or some other quantifiable method, then somebody might be able to run an experiment and find or model relationships between "great canopy coverage" and PAR, intensity, spectrum spread, or something else that could be fairly easily measured or observed.