This is from "Nitride Phosphors and Solid State Lighting" by Yamamoto et. al.
"
In general, white light can be created with LEDs in two primary methods,
as shown in Figure 1.6:
1. Multi-LED chip approach, in which light coming from three monochromatic
red, green, and blue (RGB) LEDs is mixed, resulting in
white light to human eyes.
2. Phosphor conversion, in which a GaN-based blue or UV LED chip is
coated with a yellow or multichromatic phosphor. The mixing of light
from the phosphor and the LED chip appear white to human eyes."
View attachment 2417998
So really some manufacturers are just using metamerism to get us to see white, but in reality it's RGB (Blue pump with a Red and Green phosphor) added. So do you want your "white" light from an RGB (and sometime Y) phosphor conversion process or straight from individual mono diodes with no loss from conversion. Hmmm?
There's also a way to create "white" light by using 2 complementary dies with nm's that are shite for our purposes, but will still create the illusion of white light. Here's a section from Shubert's "Light Emitting Diodes"
"White light can be generated in several different ways. One way of generating white light is
the use of two monochromatic colors, called complementary colors. Two complementary colors,
at a certain power ratio, result in tristimulus values that cause the perception of white light. The
wavelengths of complementary colors are shown in Fig. 12.1.
The numerical values for monochromatic complementary wavelengths are given in
Table 12.1."
View attachment 2417923
Far as I know there is only one way to make a true full spectrum white and there isn't any company that does, (but things move fast and I could be wrong). Too expensive and efficacy sucks supposedly. But one day when the performance is there, white LEDs might just dominate. And according to the great book "Practical LED Design" the only way to truly know that a light will work for it's purpose or not is TO BUILD IT. Still one can't make any judgements on white LED growing performance without knowing what technology the LEDs are tied to IMHO.
And remember SDS boutique panel makers like PlantPhotonics/Hans don't care about white. Are they ignorant/limited? Also ever see what happens to a severely broken bone when it's not set by a doctor. Nature isn't always right.
What up Major Coco? Now there's a man who knows something about growing with whites!
Well...
If you can tolerate some babblin',I'll try to explain....
First of all, what you say about generation of white light,are accurate enough....
But....
You're messing up ,( kinda ) human vision and plant utilisation of light ....
Which are way totally different things ...
.........
Human retina ,has 3 kinds of "colour" photoreceptors ....
One for blue,one for green and one kind for red light....
So,in fact,what we humans sense as "white light" is actually those 3 basic 'colours' mixed in different variations....
So ,yes ,an RGB led ,will obsiously appear that is irradiating white light...
Will the plants also sense ,the same ?
No...
Plants have more than three "photoreceptors.....
In fact ,they have plenty enough (known & unknown ) ,that they can "sense" all the visible to us wavelengths and more than that ...(UV & FR )....
So actually ,to a plant ,an RGB led ,is a light source that emits Red ,Blue and green light...
No violets,no yellows,no ambers,no this ,no that ....
Just 3 spikes ....Nothing more in between....
...........................................................
But there's also another way to create white light ,for human vision...
Not only the combination of the 3 " primary" colours....
There are 3 more combos....
1) Blue + yellow=white
2) Red + Cyan =white
3 ) Green + Magenta = White ......
From those 3 ,mainly the first combo is used to create white light ....
( i.e . blue chip and yellow
Fluorescence ...)..
Adjusting the ratio between blue & yellow ,different "temperatures" of white light are created....
But ,there's a big difference with RGB white.....
The spectral curve ,in white-phospor- leds ,is
continuous throughout almost all the range of 400-700 nm ....
So the plants ,sense a way different light quality ,than from RGB leds...
More "complete" or "full"....
Way different light ,there...
Now...Are these phosphor white leds ,good for plant growth ?
Well yes,but they sure can be better ,if the flouorescence is moved towards the reds...
But then ,what would be the difference from RGB leds ?
Again:
Continuous spectral irradiation and not just three spikes...
Huge difference for plants...
Way huge...
==================================================================
And remember SDS boutique panel makers like PlantPhotonics/Hans don't care about white. Are they ignorant/limited?
This means nothin' to me....
Once upon a time ,the majority of people thought that Earth is flat and is the center of the universe ,while being dead still.......
They were so dam' sure about these ,that .....
They almost kill ,everybody who wouldn't agree... ( G.Galilei )....
Or a more 'up-to-date' another example:
Some people who are thought to be ' wise ', 'educated ' or ' intelligent ',still hunt down ,at year 2012 AD ,
a certain plant and all it's ' users ' or 'growers' ..Like,as if it was / is the source of every evil,upon this planet..The same people,who would exterminate whole nations just for profit...
Intelligent ? ..Or just sick in their minds ?
... Complete Darkness & Sickness...
Now...
Boutique panel makers ,probably ,care for the same " profit " thing ,mainly,eh ?
I do not give a ... ,about them ...Or about ,what they think or believe....
I do have my own brain,to work out / solve /realise those and many other things ....
=================================================================================================
Also ever see what happens to a severely broken bone when it's not set by a doctor. Nature isn't always right
Nature doesn't work ,in human terms...
A broken bone ,in wild nature ,probably it would 've meant death of the organism.
( By one way or another...)
Doctors & medicine ,are human things...Not natural ones....
........
Of course Nature isn't always right...
But were it fails , also exterminates it's fails...
Evolution.Try & error...The weak /fails/mistakes get vanished (eradicated ),immediately...
Nature has not any 'remorses',about it.....
=================================================================================================
So do you want your "white" light from an RGB (and sometime Y) phosphor conversion process or straight from individual mono diodes with no loss from conversion. Hmmm?
What you loose in conversion (quantity ) you gain in quality of light...
A new chip of 500mW will have 15-20% losses from Phosphor....
So 400mW left (example) ....If the 80 % of those is in red wls....
320mW at reds.... Not that much difference,in power terms, from an actinic red....
Well,with a really wider wl range at reds...
-Actinics have poor quality and way high powers...
Reds ,especially,can cause pretty easily photoinhibition,photorespiration and light saturation...
Why ? Because they have a limited wl range (spike ) ,which makes the plants overreact ..
Most of times ,giving wrong signals to the plants...
Few only makers( i.e Area 51-EraserHead ) or DIYers (i.e. Guod ... ) ,had the wisdom to balance out their actinic reds ...By introducing 'counter-acting' wls ....(GL,BL & FR )
But still actinics ,have spectral blending -distributing issues & limitations....
Not easy to achieve an "even " irradiation ,regarding quality of light ..
=========================================================
P.S. : Plants are not green....
We just see them as green,with our limited vision..
In fact they reflect way more FR light than green....
But since we are not able to see FRL ,we just see what we are able of...
The
small percentage of green reflected...
With an IR camera ,one can see an approximation ,of the true colour of plants ..
(Reddish brown ) .
.
...