Diffusers.. Yes, No, Depends

I searched for a discussion on diffusers but didn't find much, a comment here or there.

What say you on using diffusers with popular COBs? Assuming Lidel reflector equipped, is it a simple preference, a yes or no? Or does it depend, if so on what?

I've never taken true lux/par measurements, but thinking about things I've read, I'd say it depends detailed PAR mapping. Say they rock at preventing hotspots, I guess if I had a problem I'd use them, so it depends? Nothing solid without par?

Jump in folks thanks

Six9 said:

I searched for a discussion on diffusers but didn't find much, a comment here or there.

What say you on using diffusers with popular COBs? Assuming Lidel reflector equipped, is it a simple preference, a yes or no? Or does it depend, if so on what?

I've never taken true lux/par measurements, but thinking about things I've read, I'd say it depends detailed PAR mapping. Say they rock at preventing hotspots, I guess if I had a problem I'd use them, so it depends? Nothing solid without par?

Jump in folks thanks

Click to expand...

They're great if you have hot spots. That'd about it.

Hi six9!
From what I've read, diffusors cause 5-8% light loss depending on used materials (glas, ppma, ...)but otherwise plants in a greenhouse can profit from diffuse light by up to 12%.
I think, the most interesting diffusers currently are fresnel lenses because they additionally can focus the light and gives a really good uniform light distribution without hotspots.
They are also available in many variants, round or square, multiple angles like 60°x 60° degrees or 60°x 90° for square fresnels and 40°, 50°, 60° or 90°degrees for round and there are many more angles available. Especially for a rectangular breeding area this is very useful!
They can also mixing different light sources or colours like white and deepred in a better way like traditional lenses.

But it is difficult to calculate what the best choice is because you have to consider the beam angle of the LEDs themselves.
Most of all COBs have 115-120 ° degrees but when combined with monos like hyperred Osrams SSL 80 (= 80 ° degrees) you will run into some distribution errors.
In case of fresnel you should only choose LEDs with the same beam angle or you will need secondary optics to get the same beam angle from each LED!

i run a mix of diffesed light and not seems to work well

Shouldn't be any other correct answer besides 'it depends'

Right now I am not using any and my 4K cobs have no reflector to minimize hot spot and spread their 4K love a little more. So no diffuser. The main advantage I see is protection of your investment. Right now I am not looking to lose 5% light and I don't foresee damage to the cobs from water. I would buy some for sure if storing or transporting the lights.

COB light is already very diffuse. It has a very wide beam angle and the light is coming from many points distributed over the grow area.

Sunlight is very direct (you see hard edges on shadows) and there is plenty of it. More than the plants can use even. So for greenhouses it makes sense to use diffusers (and it actually increases yields), but not for COBs.