Lens and Reflector Optics for COB

What Optics do you use in your DIY Lamp

  • No Optics

    Votes: 132 45.4%

  • Glass Lens

    Votes: 58 19.9%

  • Reflector

    Votes: 118 40.5%

  • Silicone Lens

    Votes: 23 7.9%

  • Other

    Votes: 6 2.1%
  • Total voters
    291
Future Skills

Future Skills

Member
alesh said:
Well, that explains it. You can have bare COBs closer to canopy, covering the same area. I'd guess that those differences wouldn't be noticeable then. It's more proof of incorrect use than of lens being beneficial IMO.
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Also, if they're at the same distance from the canopy, the plants beneath the lenses are receiving a significant amount of light from the bare COBs (delivering at 115 degrees, basically everywhere). This kind of ruins the accuracy of comparisons.
 
Future Skills

Future Skills

Member
This gives me an idea. Would it make sense to use Ledil Angelina reflectors on say 90% of your COBs@ 3500K then mix in a few 5000k evenly throughout without optics to get a good spread of the higher color temperature all over the canopy?
 
F

flexy123

Well-Known Member
Just want to thank for this fantastic thread and the comparison data.
I myself use the 80deg lenses. I like them also because they seal off the LEDs from dust etc.
Be aware tho that the lenses are likely the heaviest part of the entire fixture, they're massive.
 
ttystikk

ttystikk

Well-Known Member
flexy123 said:
Just want to thank for this fantastic thread and the comparison data.
I myself use the 80deg lenses. I like them also because they seal off the LEDs from dust etc.
Be aware tho that the lenses are likely the heaviest part of the entire fixture, they're massive.
Click to expand...
I use those very same lenses and you know what? I LOVE THEM!
 
hillbill

hillbill

Well-Known Member
Seems bare cobs would be ideal for a half pipe type grow. Just dare those photons to get to the "highly reflective side walls".
 
R

rollyouron

Well-Known Member
ttystikk said:
My very informal, ad hoc test is between CXB3590 with 80 degree lenses and bare.

I'm getting much better results under the lenses, I don't pretend to know enough about optics to venture any explanations.
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I running 1 bar bare one bar with reflectors and one bar with lens. This is my second run like this and the bar with the lens are noticeably better. When I say bar that's 4 3590's on each.
 
ttystikk

ttystikk

Well-Known Member
rollyouron said:
I running 1 bar bare one bar with reflectors and one bar with lens. This is my second run like this and the bar with the lens are noticeably better. When I say bar that's 4 3590's on each.
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It's been explained to me that the lenses project the light a bit further, so it should be mounted 6" further away from the canopy than the bare lens unit.
 
F

flexy123

Well-Known Member
If you DIY/design your lights, just make sure you don't have openings all the way through in the heatsink above the lenses, and if you do (for wires etc.) seal the openings off. Reason being that a little dust has the tendency to fall into the lenses. Seeing that you might possibly want to clean the lenses every few months or so you should also make sure you can easily remove them. My bar is a pain in the ass since some screws are UNDER the fans, so for simply unscrewing the lenses I would need to remove the fans...then access the screws etc. Bot it works halfway just removing one screw for the lens holder and carefully slide the holder w/ lens, then I can remove the lens and clean it. Just so you know when you design your fixtures.

And, extra tip: Getting a finger in a running fan is VERY PAINFUL, I have bloody spots in my greenhouse from that ;)
 
F

flexy123

Well-Known Member
[QUOTE="ttystikk, post: 12440265, member: 3242´ß7"from the canopy than the bare lens unit.[/QUOTE]

What is your "standard" distance (without lenses), for a bar w/ 4x COBs, for vegging and for flowering? (Would have to go through my email but those who made mine told me 50cm for veg and 20cm for flower, but this was w/ weaker LEDs, 3070s driven at 1400mA and NO lenses. I have 3590s driven at up-to 1750mA, currently dimmed to 900mA or so, 30W for each for vegging). Still not entirely sure about distances, have that problem ever since I started growing :)
 
ttystikk

ttystikk

Well-Known Member
flexy123 said:
"from the canopy than the bare lens unit.

What is your "standard" distance (without lenses), for a bar w/ 4x COBs, for vegging and for flowering? (Would have to go through my email but those who made mine told me 50cm for veg and 20cm for flower, but this was w/ weaker LEDs, 3070s driven at 1400mA and NO lenses. I have 3590s driven at up-to 1750mA, currently dimmed to 900mA or so, 30W for each for vegging). Still not entirely sure about distances, have that problem ever since I started growing :)
Click to expand...
I'm running between 8"and 16".
 
BuddyColas

BuddyColas

Well-Known Member
flexy123 said:
[QUOTE="ttystikk, post: 12440265, member: 3242´ß7"from the canopy than the bare lens unit.
Click to expand...
What is your "standard" distance (without lenses), for a bar w/ 4x COBs, for vegging and for flowering? (Would have to go through my email but those who made mine told me 50cm for veg and 20cm for flower, but this was w/ weaker LEDs, 3070s driven at 1400mA and NO lenses. I have 3590s driven at up-to 1750mA, currently dimmed to 900mA or so, 30W for each for vegging). Still not entirely sure about distances, have that problem ever since I started growing :)[/QUOTE]
Not being a smart ass, but a LUX meter can be your friend. It is all I have and it really helps me on setting cob height for a good even spread of photons, dimming, and cob bar placement and even how much the reflective walls are helping. And if you get one, I'll share the top-secret conversion factors so you have a ballpart PAR meter!
 
cdgmoney250

cdgmoney250

Well-Known Member
Does anybody by chance have the mounting dimensions for the KB120 lense handy?

EDIT: nevermind. Found them.
 
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