Question on the use of Prismatic Diffuser Panels on lighting

[BirdieNumNum]

This premium LED Veg light uses a prismatic diffuser

"The diffused borosilicate glass lense scatters the light over the grow area ensuring uniformity (no hot spots) and penetration into the plant canopy. "

This article The Ultimate Lighting Guide for Cannabis Cultivation says "Seedlings, clones, and mother plants can be successful with just 200 to 400 μmol∙m-2∙s-1 PPFD. For plants in the vegetative growth phase of cannabis 400 to 600 μmol∙m-2∙s-1 PPFD can be sufficient" so presumably this light is aimed at seedlings/early veg.

I wonder if anyone uses a diffuse to reduce hot spots and diffuse the light from a COB during veg stage to reduce hot spots.

I have made one from an acrylic prismatic panel which I hang off my cob heatsink for early veg but I am a noob grower

Use of a dimmer switch achieves something different - and I presume people increase light intensity as veg stage progresses.

 

[Old Salt]

I don't use a diffuser. My COBs are adjustable, up to 65W, and are on a 30cm / 12" grid. The eight COBs cover a 2' X 4' canopy.

Eight COB Light for a 2' X 4' (60cm X 120cm) Tent​

 

[TorturedSoul]

Nice, even, and powerful, Old Salt .

With a diffuser, fresnel lens, or any kind of lens, I'd try to get some kind of high quality optic (glass) product instead of plastic. You want as near to 100% of the amount of light coming out the bottom of the thing as went in that you can get, because you're paying for 100% of it on your electric bill each month, either way.

 

[Old Salt]

Nice, even, and powerful, Old Salt.

With a diffuser, fresnel lens, or any kind of lens, I'd try to get some kind of high quality optic (glass) product instead of plastic. You want as near to 100% of the amount of light coming out the bottom of the thing as went in that you can get, because you're paying for 100% of it on your electric bill each month, either way.

It's way too much for the tent by design. I was fed up with all the false claims made by many of the low-cost light manufacturers. It basically put me off of buying from any LED manufacturer. She puts out more than 120,000 Lux at one foot, anywhere in the tent. That's why I have the dimmer installed.

 

[TorturedSoul]

I've seen a lot of threads here and there on the Internet where folks recommended one COB per square foot, run at 50 watts per. What that amounts to in practice is going to depend on choice of band/model of COB, of course, since they operate at different efficiency levels. But the people seemed happy, didn't seem to feel that they were too much... and the pictures showed really nice plants/buds.

Depends on strain choice, I suppose. Indicas do well at light levels that would leave some sativas wanting, and it probably would be too much for autoflowering strains, since they're flowered under 50% or more hours' worth of light per day than photoperiodic strains.

As you mentioned, you can easily reduce the output of your lighting setup. That's a really handy feature. One of my LED products has it, one other one has two switches (well, three, but one is strictly for UV supplementation), but the others are fixed-output. The only HID stuff I have right now is a 400-watt one, and it can be adjusted from "400+ watts" down to 250. I wish I could have the option to adjust all of my devices at least that much (simple low/medium/high/extra switch).

 

[BirdieNumNum]

Trying to find a glass one is a challenge.

I do have a dimmer on the XL Cob

 

[Mayne]

Good therory. but that diffuser is hummmm, just odd i guess.

A diffused light is something i plan on doing down the line. But i was going to use SolexPanels for greenhouses. I think it would be great especially for COBS, because they break the light up evenly, and green house plants thrive because of it. Put im talking about a 3x3 plastic panel, curved like a mini green house over my plants.

 

[TorturedSoul]

That's an interesting product, but it's meant to be used in conjunction with one specific light source - the sun. I mention this because that's a stronger light source than most of us have in our grow rooms, lol, and:

The unique Solexx greenhouse covering transmits 70-75 percent of the available light. Most plants only need 40 percent light to grow, but 70-75 percent available light is the optimal growing range.

In other words, the product blocks 25% to 30% of the light. Something to be aware of when figuring your (artificial) lighting needs, so you can add that much "extra" to begin with.