Found this forum when researching information about lamps and LED lighting.
This is my first message, so I beg your pardon if I am not asking my question in the right place.
I have been trying to understand visible light, lumens, and actual photon radiation emitted by LEDs.
Also I have been going through datasheets from various LED diode makers only to find out to my surprise how actual light output per watt is exaggerated (given they drive the LEDs at much higher currents, reducing light per watt efficiency…)
So I have been searching for couple hours now and for life of me, I can not find the following information:
- How are lumens calculated?
I understand that a green photon appears the brightest, followed by blue then red.
But how much brighter is green light compared to red, deep red, or my favorite Royal Blue at 440nm?
What is the ratio?
My English is really not that bad but I feel like I screwed this up.
Literally after 2 hours of googling still can not find the information on this.
From Wikipedia luminosity function page
So 450nm blue is only ~7% as bright as 560nm green. (With the doted curve, photonic vision : vision under ”well lit condition” )
Hence why excess of blue light isn’t good for the eyes, the pupils stay dilated because it’s not very bright which let a lot of energy go to the retina.
i have green e10, great thrower, once i accidentally shined it in my eyes, wow, i had lime green spot in front of me, for several hours, i had accidentally shined white lights into my eyes many times, but even from 14k lumen light my eyes (d18) they would recover in 15-20min, but green light that had 10 times less lumens, burned my retina a lot more, and effect lasted for much much longer.
Thank you so much for linking me to your post !!
I really appreciate it. You have done an amazing job and it’s so great to have this data easily accessible.
