Its not overriding anything. The inverse square law is simply the mathematical expression of one extreme - a point source emitter with maximum radiative spread. The opposite extreme is a 100 percent reflective tube of infinite length with the same diameter as the emitter. Such a tube would have uniform intensity all the way down its length - a fibre optic cable almost achieves this but not quite, due mostly to internal absorption. Our lights fall somewhere in between those extremes. And you're correct, the factors are too complex to calculate to any realistic degree. The best we can hope for is to measure it and see how we are doing.
Sorry! But you can not override laws of nature, not without magic!
Remember these guy for some no good reason just like to blow smoke up my ass. The above is 100% bullshit. why?
The problem is overlapping and reflection makes the computation so complex that you need probably a small super computer to include all the factors.
No I, did it with with less than 10 lines of code
He's confusing a point source with a A lambertian surface which is defined as as surface reflects or emits equal (isotropic) luminance in every direction. Looks similar to this. where ISL does not work.
LOL - The Inverse Square law is a mathematical function that describes a point source radiating 360 degrees in 3D infinite space..
LOL - The Inverse Square law is a mathematical function that describes a point source radiating 360 degrees in 3D infinite space. Last time I looked I was growing in an enclosed, reflective very finite space with a light distributed across a 2 ft by 4 ft area.
Look again. Verify your source. Show me I'm wrong.
The light source does not have to be a isotropic source i.e. 360°.
It makes zero sense for it to have to radiate 360°. or could you please 'plain why I am wrong.
It does NOT radiate into 3D infinite space. It would have very little value if that were true. So are you saying Inverse Square has no practical use on this planet? Or could you give me direction to this infinite 3-D spot on this planet where it works.
Now me. this is how I think ISL works.
As a surface is illuminated by a light source and the surface moves away from the light source the surface appears dimmer. Getting dimmer faster than it moves away from the light source. As if the dimming rate distance is associated with the distance squared.
The light source only needs to approximate a point source. The distance need only be 5 times greater than the largest dimension of the light source. That is know as the "Five Times Rule". In other words you need to be a few miles away from the sun or it won't work well with the sun.
No, it does not apply, it never has applied and it never will apply in any meaningful manner.
Now I am confused. The problem is when I say stuff, I do not just pull it out of my ass like you have apparently just done.
Inverse Square Law:
To confirm ISL actually works, I decided to measure a strip of 16 LEDs with a spectrometer at six different heights. The procedure was to measure one height, then calculate the five other heights using ISL, then measure at the five heights.
The first attempt had too much error like 5-10%
The I made the calculations as 16 separate point sources for each LED on the strip
I thought about it and I decided to try calculating using each individual LED's spacial radiation characteristics, (e.g. the angles and their intensity at each angle with respect to the spectrometer's sensor position) and each distance being the hypotenuse of the right angle associated with each LED. Essentially 16 separate trigonometric equations to use as the distance in the ISL formula.
I also used wire shelving (as shown) to make the measurements at each distance repeatable.
My calculation then match the spectrometer measurements with ≈1% error.
The math
ISL Formula Highlighted intensity[$angle] was entered from the intensity and angles in the datasheet's spacial radiation characteristics.
$ref = 3.93
for($i = 1; $i < 7;$i++){
$height = $i * .7857142857 + $ref;
for($j = 0; $j < 8;$j++){
$offset = $j * .7;
$angle = rad2deg(atan( $offset/$height));
$distance= $height / cos(deg2rad($angle)) ;
$lux = pow($ref/$distance,2) * $intensity[$angle];
$total += $lux;
}
}
datasheet's spacial radiation characteristics.
Results with Error in %
Total Error 1.38%
Columns: Distance, Measured, Calculated, Error
0 3.93 440 440 -----
1 4.71 347 350 0.83%
2 5.50 270 283 4.82%
3 6.28 230 233 1.22%
4 7.07 193 196 1.34%
5 7.85 164 166 1.09%
SUMS 1644 1667 1.38%
Notice Measurements were taken in a reflective very finite space with a light distributed across a 2 ft by 2.5 ft area.
AND GUESS WHAT?
THE INVERSE SQUARE LAW WORKED!!