Properties of the LEDS

[TAURUS]

Hello,

I was wondering how much LUX the red/green/blue/white leds produce ?

Thanks.

[Andy]

No idea but I'll see if I can find out. Why do you ask?

[TAURUS]

Dear Andy,

As I'm studying the relationship between the increase of serotonin and light, I need to know how much LUX is produced relative to the brightness dial on my PROTEUS, so when making sessions I can incorporate this. I would like to write a "serotonin" session using white leds.

I can of course buy a LUX meter and do the tests myself but before spending cash I wondered whether the manifacturer could help me. In our country (Belgium) we can have long periods of grey days and lots of people are suffering from Seasonal Affective Disorder (SAD) ... I was told in the North of Europe things can even be worse (especially when there is no snow to reflect the little available light).

Thanks for any info.

Regards,
Wim.

[Marisa]

Dear Andy,

As I'm studying the relationship between the increase of serotonin and light, I need to know how much LUX is produced relative to the brightness dial on my PROTEUS, so when making sessions I can incorporate this. I would like to write a "serotonin" session using white leds.

I can of course buy a LUX meter and do the tests myself but before spending cash I wondered whether the manifacturer could help me. In our country (Belgium) we can have long periods of grey days and lots of people are suffering from Seasonal Affective Disorder (SAD) ... I was told in the North of Europe things can even be worse (especially when there is no snow to reflect the little available light).

Thanks for any info.

Regards,
Wim.

It's the frequency (Alpha) that you want to target to release serotonin. The color of the leds (I'm pretty sure) will not do this. For the people with SAD, what they need is a full spectrum light - however, the Proteus can help with this as well by targeting the alpha brain waves (8-11hz). You may want to throw a bit of SMR (12-15hz) in there as well (at the beginning of the session and again at the end).

M.

[TAURUS]

Dear Marisa,

Thanks for this info. I will certainly look into these Alpha frequencies.

I will shortly be testing the available LUX emitted by the leds. While on a sunny day 100.000 LUX is present, an overcast sky has between 100 - 10.000 LUX, while home/office light is between 100 - 1.000 LUX. Light boxes to treat SAD produce between 2.500 to 10.000 LUX, with the latter value being typical.

Curious to know what light levels PROTEUS yields with the brightness dial set to minimum/maximum.

Kind Regards,
WIM.

[Robert Austin]

I'll have our engineer pull the data sheets for those LEDs... but: LED brightness is normally measured in millicandelas, and sometimes (the superbright ones used for architectural lighting etc.) are measured in lumens.

-Robert

[TAURUS]

Dear Robert,

Thanks for the trouble.

As far as my knowledge stands , there are three technical aspects not to be confused (a) lumen (lm), (b) candela (cd) and (c) lux. LUMEN is a measure of the quantity of light in all wave lengths of the visible spectrum emitted by a source of light. So it represents the luminous flux emitted in a certain direction. CANDELA is the intensity of the former luminosity, and 1 cd = 1 lm/1 sr (sr or steradian is the solid angle subtended at the center of a sphere of radius r by a portion of the surface of the sphere having an area r?, and is dimensionless). LUX is the unit of the actual luminous flux received on a surface and 1 lux = 1 lm/m?. This last value is the one I'm seeking. How much light touches the retina ?

Given that cd = lm/sr or (1) lm = cd.sr, we know, given lux = lm/m? and substituting (1), that lux = cd.sr/m?.

So if your technician knows the cd I can calculate the lux. I remember reading somewhere a value of 1500 mcd, but I could be wrong.

Sorry if all of this has gone way into the technical. When my LUX meter arrives, I will be testing the LEDS directly.

Best Regards,
WIM