345w 5000k 95Ra CXA3590 4 COB panel PPFD mapping Lens Vs no Lens

[Geyapex Technology]

OK let's do some interesting tests on one COB grow panel with 4 pcs of 72v 5000k 95Ra CXA 3590.

the driver is meanwell HLG-320H-1050B

the Apogee PAR meter we use

 

[Geyapex Technology]

this is the Dia 100mm 90 degree optic lens we use on the panel

This is normal plane glass without degree for anti-dust

Here is comparison

 

[Geyapex Technology]

get some ready...

 

[Geyapex Technology]

Here is the result... it's easy to see the difference between with lens and without lens, which one do you prefer? we have both haha

 

[Geyapex Technology]

 

[wietefras]

The thing is that uniformity is what determines the actual height at which the fixture should be. So it makes no sense to compare with and without optics at the same height. You need to compare when both are a the same uniformity.

When you don't have optics on, you can drop the fixture to about half the distance. In this case to around 18.5" to get the same uniformity as with optics at 32". That's how you should use them in reality and therefore how you should compare them.

 

[Geyapex Technology]

The thing is that uniformity is what determines the actual height at which the fixture should be. So it makes no sense to compare with and without optics at the same height. You need to compare when both are a the same uniformity.

When you don't have optics on, you can drop the fixture to about half the distance. In this case to around 18.5" to get the same uniformity as with optics at 32". That's how you should use them in reality and therefore how you should compare them.

actually it's impossible to make the same uniformity by lens and without lens at different height, the PPFD uniformity of without lens is always better than with lens, it's not matter of height but depending on different focusing way of light, if you use 90 degree optics lens on the light, the PPFD of the center area must be higher than without lens, and penetration will be much more stronger but the unformity won't be so good as without lens. so people need to adjust the lens configuration according to the grow area they need and the height of plants

 

[wietefras]

Uniformity IS a matter of height.

Of course if you are using a small box in the center as your light then uniformity will suffer, like shown in those matrices. The first matrix has horrible uniformity too.

Still the point is, this comparison is useless as is. No one would hang the thing at 32" without lenses. Perhaps 18.5" is too low to overcome the impractical shape, but it should be much lower than 32"

 

[Geyapex Technology]

Uniformity IS a matter of height.

Of course if you are using a small box in the center as your light then uniformity will suffer, like shown in those matrices. The first matrix has horrible uniformity too.

Still the point is, this comparison is useless as is. No one would hang the thing at 32" without lenses. Perhaps 18.5" is too low to overcome the impractical shape, but it should be much lower than 32"

the problem is when people can't change the power draw of the light, and can't adjust the hanging height, but they want higher PPFD at some certain area, then they have to use optics lens to make it, that's why we see there are different optics lens with different degree on market, the comparison will help people know the difference of lens and without lens to lighting coverage and penetration. it's only a simple and intersting test, I think other growers may need that

 

[wietefras]

@Geyapex Technology , Still, why not test the fixture at 18.5" and do the same matrix. You will see uniformity is much closer to the fixture with optics @ 32".

People who can fix the height of the fixture will be much more interested in that. How many people cannot change the height? Besides, people who cannot change the height have no alternative but to use optics and accept their light loss. So they won't care for the measurement without optics anyway.

 

[Big Green Thumb]

I agree, a comparison at 16-24" would be interesting. I personally am at 16" above canopy with no lenses.

 

[Geyapex Technology]

@Geyapex Technology , Still, why not test the fixture at 18.5" and do the same matrix. You will see uniformity is much closer to the fixture with optics @ 32".

People who can fix the height of the fixture will be much more interested in that. How many people cannot change the height? Besides, people who cannot change the height have no alternative but to use optics and accept their light loss. So they won't care for the measurement without optics anyway.

oh sorry I just found my mistake, the chart is at 24'' instead of 32'', we tested 24'', 36'' and 48'' PPFD, I will correct it soon, and yes, we will hang the light closer and please suggest 3 distance which are frequently used by growers you think, thanks very much!!

 

[Geyapex Technology]

I agree, a comparison at 16-24" would be interesting. I personally am at 16" above canopy with no lenses.

OK no problem, 16'' 24'' 32'' is good?

 

[waynejohn]

I use 12-16" so would be interested in seeing both but just 16" would be great also

 

[Geyapex Technology]

I use 12-16" so would be interested in seeing both but just 16" would be great also

may I know how much power on the wall when you hang the light at 12''? because some of our clients ever burned the plants at that distance, also the footprint will be very limited at 12''...

 

[waynejohn]

36v cxbs @1400ma spaced around 12" from each other just bare chip no optics, if i crank it up to 1750ma i set it at 16" height but i adjust that according to strain

 

[NoFucks2Give]

Uniformity IS a matter of height.

Uniformity is a matter of height, spacing, and the view angle / Radiation Pattern Characteristics.

For example in this case a small compact fixture with 150° view angle (OSRAM SSL 150) is best at a height of 8" and spaced 12" apart.

 

[NoFucks2Give]

actually it's impossible to make the same uniformity by lens and without lens at different height, the PPFD uniformity of without lens is always better than with lens, it's not

matter of height but depending on different focusing way of light, if you use 90 degree optics lens on the light, the PPFD of the center area must be higher than without lens,

The impossible is only impossible until someone does it.

uniformity of without lens is always better than with lens,

Never say always especially when it is not true.

My take is this. It is better to have no lens and get back the 9+ percent photon flux lost to the .transmission coefficient.

So it would only make sense to use a lens if it increased the uniformity and allowed a lower height that more than made up for the optics transmission loss. And how likely is that? Certainly a 90° lens is not. You need to spread the light and get the fixture closer to the canopy. The higher the view angle degrees the better.

Well on the subject I also think if you are designing with CoBs, you should do a bar(s) rather than be stuck in the constraints of a box. What good does a box do?

 

[Geyapex Technology]

The impossible is only impossible until someone does it.



Never say always especially when it is not true.

My take is this. It is better to have no lens and get back the 9+ percent photon flux lost to the .transmission coefficient.

So it would only make sense to use a lens if it increased the uniformity and allowed a lower height that more than made up for the optics transmission loss. And how likely is that? Certainly a 90° lens is not. You need to spread the light and get the fixture closer to the canopy. The higher the view angle degrees the better.

Well on the subject I also think if you are designing with CoBs, you should do a bar(s) rather than be stuck in the constraints of a box. What good does a box do?

Thanks very much, learned again...we also have one 4 cob bar, and we wil test PPFD soon, so may I know which distacne you may like to know the PPF value

 

[wietefras]

Your fixture has a fixed spread and all that, so in this case only the height matters.

When you calculate the beam angles 90 degree angle at 32" would give the same footprint with 120 degree at 18.5". So that should be most comparable. But then lenses can be a bit of a weird thing. Often their footprint isn't as nicely formed as bare COBs.