His conclusion is not correct.
What’s so hard to get from that radiation diagram?
Just look at the surface area of the circle.
Only about 33% is green i.e. reflected with a regular reflector, whereas a recoil set up practically uses all of it, and when limited to 120° it still is almost 90%.
That’s nearly 3 times more light focussed / collimated for the recoil compared to the regular set up.
Why do you think i’m so enthusiastic about a recoil thrower?
LEDs are practically made for it.
It’s clear you have not considered what I wrote in my post above (regarding how the radiation diagram does not tell the whole story) and so this discussion is just us repeating ourselves.
You use terms i’m unfamiliar with, so it’s kind of wasted on me.
However, there’s not much more to the radiation diagram than what it shows us.
(edit) ehrmm… there is… sorry…(/edit)
The radiation diagram is not of a circle, it is of a sphere.
The way the intensity is measure is with a fixed distance, so at 0 degrees it is Xcm in front of the led, at 45 degrees it is at Xcm diagonally from the LED, at 90 degrees it is at Xcm to the side of the LED.
I think you can imagine the circumference of the circle at different heights along a sphere, like this
But since the radius increases to the power of 1/2 and the intensity decreases by cosine then between –45 and 45 degrees there is over 50% light output.
So you’re both right, the intensity graph doesn’t tell the whole story and a recoil reflector is still definitely more efficient than forward reflectors or lenses.
The radiation diagram is not of a circle, it is of a sphere.
The way the intensity is measure is with a fixed distance, so at 0 degrees it is Xcm in front of the led, at 45 degrees it is at Xcm diagonally from the LED, at 90 degrees it is at Xcm to the side of the LED.
I think you can imagine the circumference of the circle at different heights along a sphere, like this
But since the radius increases to the power of 1/2 and the intensity decreases by cosine then between –45 and 45 degrees there is over 50% light output.
So you’re both right, the intensity graph doesn’t tell the whole story and a recoil reflector is still definitely more efficient than forward reflectors or lenses.
Okay, thanks for explaining that, especially the picture showing it is (of course! silly me…) a sphere.
This also makes sense as to why i felt that we should collimate at least 120°
And afterall, had i been right, a regular reflector would be quite silly for an LED, and there would be a LOT of silly lights out there.
Mostly due to how the distance from the LED to the lens surface is longer than the distance from the LED to the reflector surface.
Since the distance is greater, the “difference” angle of light coming from the LED is smaller, leading to less divergence.
That’s also the reason why outer parts of a reflector (farther from the LED) collimate light better, like in that image by djozz which I can’t find atm lol
Alright, but what if we use a smaller aspheric lens, resulting in the same size hotspot at (for example) 30 meters?
Wait, i’ll try it myself, see what we get.