Lenses/ Reflectors worth it for COB?

G

goofy81

Well-Known Member
I did a run and used the 90 degree angelinas. A few weeks into flowering i actually took them off on some of the COBS as some of my branches were quite high and the anjelinas cast a shadow. Mind you, my COBS were about 6 inches away from my canopy running at near 50w @ 1400ma. Didn't experience any bleaching either.
 
Trippyness

Trippyness

Well-Known Member
goofy81 said:
I did a run and used the 90 degree angelinas. A few weeks into flowering i actually took them off on some of the COBS as some of my branches were quite high and the anjelinas cast a shadow. Mind you, my COBS were about 6 inches away from my canopy running at near 50w @ 1400ma. Didn't experience any bleaching either.
Click to expand...
You here 6" with reflectors or bare?
What are your final thoughts? Use reflectors or not?
 
G

goofy81

Well-Known Member
I will definitely use them because i have them
But if there's a section on my canopy thats grown taller than the rest, i'll take them off for that section. 6inches bare or with reflector, it didnt matter as it was my first run with LED. I just wanted no shadow spots and was waiting to see bleached leaves/bud (however it never happened).
I'll probably raise them with my next run for even more uniformity and better spread though.

Also, note that my growing area is quite large so my method doesn't apply to most of you. 12ft x 17ft. So i'm aiming the LED's at the edge on an angle.
 
Trippyness

Trippyness

Well-Known Member
goofy81 said:
I will definitely use them because i have them
But if there's a section on my canopy thats grown taller than the rest, i'll take them off for that section. 6inches bare or with reflector, it didnt matter as it was my first run with LED. I just wanted no shadow spots and was waiting to see bleached leaves/bud (however it never happened).
I'll probably raise them with my next run for even more uniformity and better spread though.

Also, note that my growing area is quite large so my method doesn't apply to most of you. 12ft x 17ft. So i'm aiming the LED's at the edge on an angle.
Click to expand...
Did you find you had better penetration with reflectors?

Thanks for the info.
 
sixstring2112

sixstring2112

Well-Known Member
Rahz said:
Single emitter, 3 spot measurements representing a 3x3 grid of 8"x8" squares in a 2x2 reflective area, with and without reflectors.

1x center square reading
4x side square readings
4x corner square readings
Average

View attachment 3816268

Note the 11" reflector readings -vs- 9" bare readings. Similar center and similar corner readings. Reflector is doing better in the side squares. Across the board the reflector is providing +500 average while bare is providing -500 averages.
Click to expand...
would like to see a similar test in an open space like mine
 
Trippyness

Trippyness

Well-Known Member
sixstring2112 said:
would like to see a similar test in an open space like mine
Click to expand...
Numbers would be less due to no reflection or little reflection.
Thats where I think reflectors would benefit most due beaming the light where otherwise it would be much more lost than reflector loss.
 
G

goofy81

Well-Known Member
Trippyness said:
Did you find you had better penetration with reflectors?

Thanks for the info.
Click to expand...
I think people are using the word penetration too loosely. The more light sources you have, the more angles the light comes in from, causing less shadows right? That's why Cree probably thought it was crazy people used cobs to grow. Technically, if you got a boat load of small led every 1cm square apart you'd probably have less shadow area.

In saying the above, my grow is different to everyones. I've got a shit load of cobs so I'm going to get light from a LOT of angles (especially the middle of my room). Someone using a small space might concentrate on really good wall reflection efficiency. But what do I know? I've never grown in a space smaller than 12ft x 12ft :)
 
Last edited:
Trippyness

Trippyness

Well-Known Member
goofy81 said:
I think people are using the word penetration too loosely. The more light sources you have, the more angles the light comes in from, causing less shadows right? That's why Cree probably thought it was crazy people used cobs to grow. Technically, if you got a boat load of small led every 1cm square apart you'd probably have less shadow area.

In saying the above, my grow is different to everyones. I've got a shit load of cobs so I'm going to get light from a LOT of angles (especially the middle of my room). Someone using a small space might concentrate on really good wall reflection efficiency. But what do I know? I've never grown in a space smaller than 12ft x 12ft :)
Click to expand...
Gotcha
 
Rahz

Rahz

Well-Known Member
sixstring2112 said:
would like to see a similar test in an open space like mine
Click to expand...
At your service, same test without reflective walls.

Reflectortest3.jpg

I'm curious to know what your findings are, and the methodology if your results were different... specifically emitter output and grid/space tested in.

In a 3x3' area 8 emitters in a grid or 9 emitters with the center bare would probably be the smart move, but for people running 6 cobs in a 3x3 or 8 in a 4x4 I think results will be better using the reflectors. I have ran bare, 23 cobs in 16sq/ft but the difference there is they were about 12 par watts each and spaced about 8 inches apart in a hex grid. Tops could reach about 4" before they would start to burn. If I didn't want to raise the light I just used a string to lean the cola away from the emitter. Several times I let them grow up through the lamp frame.
 
T

TAGrows

Member
Sorry to dig up an old post, but I am wondering if I should be using the angilina 90 deg reflectors and little clear lenses. I am in an 8x8 tent. I have all my cobs spaced at about 15 inches apart. Seems like the reflectors give the best amount of light everywhere other than directly below the cob. Just to clarify this is with the plastic cone reflector part and the little clear dome lens?
 
DrGreenT420

DrGreenT420

Active Member
TAGrows said:
Sorry to dig up an old post, but I am wondering if I should be using the angilina 90 deg reflectors and little clear lenses. I am in an 8x8 tent. I have all my cobs spaced at about 15 inches apart. Seems like the reflectors give the best amount of light everywhere other than directly below the cob. Just to clarify this is with the plastic cone reflector part and the little clear dome lens?
Click to expand...
I am also trying find this out myself. You are talking about the newish LEDIL Silicon Lens ? I have 9 cobs running in a 3x3 grow tent with reflective walls, running 1 COB per sq ft, would I benefit from either the lens or reflector, or just leave all 9 bare with the spread ?
 
TEKNIK

TEKNIK

Well-Known Member
I am quite busy at the moment but I promise before the end of this year I will conduct goniometer tests so you guys can par map these lenses and reflectors on your computer to see how the results will be using a free program called Dialux. It is the only way to know for sure how it will all work before making a purchase. My suggestion to anyone that is seriously interested in computer simulation par maps is to download dialux and learn how to use it by watching YouTube tutorials. It will take about 4 hours to learn it. I will have horticulture specific ies files for par maps for everyone.
 
You must log in or register to reply here.
Top