Reflectors on COBs: Not needed?

[NoobyMacDooby]

Was perusing a led growlight website when I came across this: "Please note, reflectors as shown are no longer available. Recent integrated sphere testing has shown a loss of almost 8-10% in PAR wattage using the reflectors vs not. Additionally, the light is able to be operated closer to the canopy with even PAR spread"

I cant however find any data on this. Is this just a marketing ploy to not bother with reflectors? The unit had the white angelina ones on.

 

[Old Salt]

I don't think it's a marketing ploy. Whenever the light is reflected off of a surface, some will be absorbed. One way of finding out is to use a light meter with and without the reflectors installed to map out your grow area. I suspect there will be a difference between enclosed grows such as a tent, and open grows in a warehouse. The reflectivity of the surfaces in the grow areas will also play a large part.

 

[Blew Hiller]

Well, depends on the angle of the reflectors, right? If they capture any light on the periphery and reflect/deflect it downward...you would have "lost" that light anyway...so whatever is captured and reflected is a bonus....maybe that logic is too straightforward..I haven't had coffee yet!

 

[Old Salt]

Well, depends on the angle of the reflectors, right? If they capture any light on the periphery and reflect/deflect it downward...you would have "lost" that light anyway...so whatever is captured and reflected is a bonus....maybe that logic is too straightforward..I haven't had coffee yet!

That's why I differentiated between open and enclosed grows. In a highly reflective tent, the sides act as reflectors into the canopy. In an open grow any light not directly hitting the canopy is largely lost.

 

[Blew Hiller]

That's why I differentiated between open and enclosed grows. In a highly reflective tent, the sides act as reflectors into the canopy. In an open grow any light not directly hitting the canopy is largely lost.

Agreed, but I just wanted to add the word downward... I'd be happier with (partially degraded) light reflected towards plants

 

[Old Salt]

We're talking COBs, which have a 90° to 120° beamwidth to start. All the light is directed down towards the canopy. In a tent, the light striking its edges above the canopy is reflected back down into the canopy with 95% or greater efficiency. In an open grow, this light is lost, unless you use the reflectors to redirect it.

 

[Blew Hiller]

We're talking COBs, which have a 90° to 120° beamwidth to start. All the light is directed down towards the canopy. In a tent, the light striking its edges above the canopy is reflected back down into the canopy with 95% or greater efficiency. In an open grow, this light is lost, unless you use the reflectors to redirect it.

Not disagreeing....my @TimberGrowLights COBS use reflectors in a highly reflective Gorilla tent...the original question seemed to be "should I buy these lights from this shady manufacturer who makes up some bs because they can't organize their supply-chain?"...my answer is no, look elsewhere and get lights with reflectors.

 

[NoobyMacDooby]

Not disagreeing....my @TimberGrowLights COBS use reflectors in a highly reflective Gorilla tent...the original question seemed to be "should I buy these lights from this shady manufacturer who makes up some bs because they can't organize their supply-chain?"...my answer is no, look elsewhere and get lights with reflectors.

Yes that's the one I'm talking about and sorry if my post came across as BS manufacturer because their lights are good. Was just wondering about removing my reflectors if they arent needed. I have a reflective surface around my grow.

 

[Blew Hiller]

Was just wondering about removing my reflectors if they arent needed. I have a reflective surface around my grow.

I wouldn't...manufacturers wouldn't add an additional piece/cost if it didn't benefit the performance.

 

[NoobyMacDooby]

I wouldn't...manufacturers wouldn't add an additional piece/cost if it didn't benefit the performance.

Thanks man

 

[PurpleGunRack]

Reflectors will focus the light in more narrow angle, and in doing so some of the output will be lost when the ligth bounces off the sides of the reflector.

The beam angle s not very wide on COBs anyway, so if you grow in a tent or otherwise employ reflective walls, you certainly won't lose anything by trying to remove the reflectors (I know a guy who's been growing without reflectors for years)

In an open area you could use reflectors on the COBs on the outer perimeter of the light setup and no reflector COBs inside the square of the reflector COBs, if that makes sense

 

[PurpleGunRack]

I wouldn't...manufacturers wouldn't add an additional piece/cost if it didn't benefit the performance.

Of course they would, if it's making them money they'd be stupid not to

Manufacturers aren't necessarily smart enough to know the science of ligths and plants, they just know how to make money by making, marketing and selling lights.

A lot of useless and/or non-scientific features and add-ons haunt LED lights almost everywhere to this day.
Whenever there is a craze about adding blue, or whatever, the grow light pushers will utilize this and make ligths with blue diodes to increase sales

Nobody knows the perfect spectrum for any of the stages in the life of a cannabis plant, and the spectrum would also have to be known for every single phenotype and then also adjusted to the environmental factors.
So why make lights where you can adjust the spectral output?

It's just business as usual....

 

[NoobyMacDooby]

In an open area you could use reflectors on the COBs on the outer perimeter of the light setup and no reflector COBs inside the square of the reflector COBs, if that makes sense

Mmm might just give that a try.

 

[Mayne]

I used them, and didnt use them, and I got almost 30% PAR boost from using them. Id just remove the 2 reflectors in the center.

Take my information with a grain of salt if youd like, but 500PAR from COBS is the sweet spot. especially with the reflectors. Your leafs with start to browns and yellow out from lack of Mag, but adding to supplement the light power will give you harsh smoke. Cobs are no joke. at least Luminus are,lol.

 

[NoobyMacDooby]

I used them, and didnt use them, and I got almost 30% PAR boost from using them. Id just remove the 2 reflectors in the center.

Take my information with a grain of salt if youd like, but 500PAR from COBS is the sweet spot. especially with the reflectors. Your leafs with start to browns and yellow out from lack of Mag, but adding to supplement the light power will give you harsh smoke. Cobs are no joke. at least Luminus are,lol.

Thanks yeah I do add a bit more calmag but it's all organics. And yes cobs are no joke. I'm thinking I could move my light frame away from the wall a bit and add another row of plants in smaller pots in the front to pheno hunt a bit.

 

[g041579]

Loose the reflectors, and lower your lights. The light has a better spread and can work closer to the canopy.
Reflectors can cause hot spots.

 

[NoobyMacDooby]

Loose the reflectors, and lower your lights. The light has a better spread and can work closer to the canopy.
Reflectors can cause hot spots.

Thanks will check that out. Interesting about the hot spots as I've got the lights at this height to prevent light stress. Will check without reflectors. Going have to start wearing sunglassess in the flower room though

 

[PurpleGunRack]

To break it down in a few simple words:

Reflectors = higher intensity in a smaller area + reflector loss
No reflectors = lower intensity in a larger area - reflector loss


So it depends on what you want to achieve........


Just saw the picture....
My advice: Lose the reflectors and drop the lights closer, lose the net and fill up that tent with plants maaaan it's only half full

Going have to start wearing sunglassess in the flower room though

Standard tactics that!
Might not seem like a lot to be exposed 5-10 minutes every day, but it adds up over the years and causes irrepairable damage to your eyes.

 

[g041579]

This was copied from Timber, check out the part on reflection.

640 Watt LED grow light fixture featuring Vero29 Generation 7 COB LEDs. Ideal for growing indoors in a greenhouse, tent or over a farming table. Using best-of-breed components the Redwood VS is a full spectrum COB LED light designed to cover a 4'x4' area for full cycle/flowering use. The unit comes fully assembled (as shown) and ready to hang.
Please note, reflectors as shown are no longer available. Recent integrated sphere testing has shown a loss of almost 8-10% in PAR wattage using the reflectors vs not. Additionally, the light is able to be operated closer to the canopy with even PAR spread.

 

[Mars Hydro]

Was perusing a led growlight website when I came across this: "Please note, reflectors as shown are no longer available. Recent integrated sphere testing has shown a loss of almost 8-10% in PAR wattage using the reflectors vs not. Additionally, the light is able to be operated closer to the canopy with even PAR spread"

I cant however find any data on this. Is this just a marketing ploy to not bother with reflectors? The unit had the white angelina ones on.

Usually the reflector can help the light more intense and also give you better coverage as well. So it is helpful, but without it, the light can also work. You can buy one when they have stock.