Color and Light?

[zozo]

As Kadir already said, there is no white light, we only perceive it like that.. If you look at the spectrum color chart, then all these colors mixed together we perceive as white.
Actualy there are 3 basic colors Red, Green and Blue, like you see in the RGB leds of all colors are emitting 100% we perceive the invironmental color as white.

A blue led could contain several different materials coated with yellow phosphor.. (I seem to be out of date and said sulfur before but using phospor. How stupid of me. ). But still that doesn't change the fact they cover the broadest spectrum of all available light sources today.

It's actualy the broad range of semi conductor materials available to produce colors making them perform so well.

 

[xim]

I heard a talk last year about how most led light is blue and the rest is mostly chemical coatings. Interestingly there are no white leds so I have no idea how we get white light out of that.
...

From what I've read, they put a phosphor material into the blue LED. When a phosphor is excited
it can convert the input light into another light with a different wavelength. In this case it converts some
of the blue light to yellow light (yellow light contains red and green). The yellow light when mixed
with the remaining blue light creates white light.

 

[ian_m]

they put a phosphor material into the blue LED

Generally a UV LED & phosphor. Same phosphor as used in fluorescent tubes. The reliability issues of LED's is that all the UV power is concentrated in a small space which degrades the phosphor and LED plastic packaging. This is why cheap white LED's go yellow as the plastic package degrades under UV light.

 

[PARAGUAY]

Then there is the theory or is it fact?of plants like Hygr polysperma Rosenverg a virus within the plant causing the red under high lights.

 

[PARAGUAY]

This was the growth after using EI fertiliseI A T5 39 watt above the duckweed I think its a Ludwigia species

 

[BruceF]

I keep what we call here Sunset Hygro. It gets red under intense light. Not so much under less light. Some plants seem to change not just leaf shape but leaf color when grown submersed.
I tend to think most viral infections are asymmetrical.

 

[zozo]

Also i experienced myself with lights from same manufacturer alledged 10.000k which had a kinda red hue to it and the 8000k where relatively white/blue. These where leds.

Comparable with the AquaticLife Marine 700+ 10000K T5HO Fluorescent Bulb which also has this redish hue according to its users.. Because they are made with purple phosphor according the manufacturer.

Now i come to think what the heck does 10000k stand for then?? It should be a relative blue light according the charts.. If you put materials in it to enhance the red spectrum then how can it still be 10000k.

So the kelvin temp specs are the same as full spectrum specs, more marketing then a technical term.

 

[BruceF]

Yes the quality of the manufacturing seems to always be a questionable and the specs are often not reliable.

I am also wondering about intensity and duration. I have recently been using stronger lights for shorter periods, At firsat I simply did this to avoid algae but now I think these burst so to speak are improving color.

 

[xim]

Also i experienced myself with lights from same manufacturer alledged 10.000k which had a kinda red hue to it and the 8000k where relatively white/blue. These where leds.

Comparable with the AquaticLife Marine 700+ 10000K T5HO Fluorescent Bulb which also has this redish hue according to its users.. Because they are made with purple phosphor according the manufacturer.

Now i come to think what the heck does 10000k stand for then?? It should be a relative blue light according the charts.. If you put materials in it to enhance the red spectrum then how can it still be 10000k.

So the kelvin temp specs are the same as full spectrum specs, more marketing then a technical term.

A colour temperature doesn't indicate a particular colour of light but a range.
I used to understand this graph (used to work in a colour printing related job).
But all I remember now is that look at the lines of Kelvin temperature,
for example, a 10000K light can be a bit blue to a bit pink as long as
its hue and colourfulness coordination is along the 10000K line.

 

[zozo]

Ok, thanks didn't know that.In other spectrum graphs it's just blue.