303 Lumen per watt in 2014?

[DavidEF]

@djozz

@jumpjack

I think we are “slightly” off topic :person_facepalming: , anyway I guess our eyes aremost sensitive to one precise color: Sun color! It was the only light source we had available for our first millions years on the Earth, so we are totally “matched” to its apparent color.

An off topic reply :party:
The perfect adapted human body sounds logical, but biology and chemistry is not that perfect at all. Forget the idea of perfect adaption, biology is often about make do with what is available, with thee simpke rule: what works, stays. In case of the light perception in our eye: it is a most primitive system with three badly overlapping receptors, but it was what was available so it had to do. Luckily our brain has a great way of dealing with the little and incomplete information so we do not notice it normally.

You do realize that our “most primitive system with three badly overlapping receptors” can see more variations of light and color than any single human-made device has ever been able to produce, right? And AFAIK, no human-made camera or imaging device has yet been able to match our eyes’ natural dynamic range either. Nor has there been a lens (that I know of) that can match the abilities of the lenses in our eyes. After all these years, it would seem that our eyes are still the better technology.

[Jerommel]

@djozz

@jumpjack

I think we are “slightly” off topic :person_facepalming: , anyway I guess our eyes aremost sensitive to one precise color: Sun color! It was the only light source we had available for our first millions years on the Earth, so we are totally “matched” to its apparent color.

An off topic reply :party:
The perfect adapted human body sounds logical, but biology and chemistry is not that perfect at all. Forget the idea of perfect adaption, biology is often about make do with what is available, with thee simpke rule: what works, stays. In case of the light perception in our eye: it is a most primitive system with three badly overlapping receptors, but it was what was available so it had to do. Luckily our brain has a great way of dealing with the little and incomplete information so we do not notice it normally.

Human vision system is a marvel of bio-technology, among numerous marvels of bio technology, which is basically nano technology on the smallest scale possible, making insanely complex systems we call organisms, which make up part of an eco system.
Human inventions are child’s play compared to living nature.
(how off topic can we get…? )

[Jerommel]

@DavidEF

Just a quickie from me, and then I’ll let it go. High pressure sodium isn’t monochromatic yellow. It does produce a spectrum of wavelengths centered around yellow, though. Here’s a picture from Wikimedia.

The main reason HPS lamps are/were in use for street lights and other forms of bulk lighting is because they are cheap and efficient. I read recently that HPS bulbs are still more efficient than LED technology, even as other forms of lighting are losing that race to the ever-improving LED tech.

As for the conversation about which color is “brighter”, you need to stick to one definition of that word if you want to get anywhere. It is known by scientists that the human eye perceives green the best.

But i think the human visual system perceives yellow as brightest, BUT none the less the receptors in the retina are most sensitive to green.

So, if you have several sources of light emitting the same power, the green will look “brighter” to the eyes. But, on a monitor, the yellow “color” is actually a mix of green plus red, so it is going to be emitting more power, and may look “brighter” as a result of that extra power.

This is not just the case with yellow.
Cyan and magenta / lila / purple (whatever you want to call it) are also combined colours on a monitor, and they’re brighter than red and blue, but less bright than yellow. However, purple / lila is less bright than green, but cyan is brighter than green.
And not only on a RGB monitor.
So what’s exactly going on?
I’m not sure, but i guess it has to do with our biological graphics card.