LED lighting - oops

[martin_h]

https://uk.news.yahoo.com/astronauts-photos-space-show-leds-084611861.html#Wp1O3zG

[JamesF]

It's possible that LED lights have made LP worse, but I don't believe that hypothesis is supported by the article.

The roads are clearly brighter in the LED-lit image, but that may well be due to the LED lighting being more focused and restricted to the areas where it is intended to be.

If they want to claim that LP has got worse then some definition of what LP is would be required, and some scientifically-acceptable means for measuring it.  Looking at a photo and saying "some bits have got brighter" frankly isn't either.

James

[FenlandPaul]

Terrible article and dodgy conclusions, which are at odds with the personal experience of many (but not all) on this forum. Is it possible that the images are showing the well-lot surface rather than light pollution (I.e. Light where it shouldn't be)?

LED lights can be extremely well focussed and targeted, considerably more so than conventional fixtures. There are some complications with broader emissions than, say, LPS lamps but the vastly improved directionality should more than compensate.

To be totally transparent, I have an interest as I help run an industrial LED lighting manufacturing business. But if I wasn't personally satisfied that LED lighting was, on balance, considerably better than the alternatives I wouldn't be doing so.

[martin_h]

That LED image could have been taken after a rain fal land show reflections from wet surfaces....

I must admit that LED lighting around here is way better than the old sodium lights.

[jam1e1]

Maybe the camera that has taken the picture has more megapixels/better optics/better resolution therefore making it appear worse?!

[jonathan]

That looks like nonsense.  All it shows is that the same areas have turned from sodium orange to sharper blue/white, which of course is going to look brighter on a photograph purely due to the colour temperature if nothing else.

What they should be looking at is the city from the side - how far above the horizon is the sky glow visible (before and after), and what stars can be seen in that same view before and after.  How about looking up from an open area of the city without street lights beaming right down on the viewer - how many stars can be counted in a specific area of the sky or a constellation before and after (either with a camera shot taken by the exact same camera, or viewed by the same person).  That seems like more of a real test.

[Psychobilly]

The majority of lights in my area have been changed to LED fittings over the last few months.  our house is above the  road so the lights are almost at eye level when I'm in the garden. Underneath them it's almost like daylight, The house opposite is below the road and  gets a lot off light from them they are going to ask to see if they can have the lights shielded - they only have the width of a dry stone wall between the road and the house... With the old LPS lights we didn't need to turn light on at night to  "head for the bathroom" now we do...

There's quite an  improvement the sky above them when the ground is dry (not that often in the last few months) quite a lot of back scatter when it's wet. Even when looking directly over the top of the fittings the sky looks a lot darker and I can see a lot  more stars.

I will take some pics when I get a chance (break in the weather)

Forgot I had taken this one... This was the "night" after they had done the closest ones to me... Since then the majority of the "sodium" lights visible in the pic have been replaced by LED as well...

Peter...

[Tinker1947]

If people think there local LED lighting is to bright then why not have the lamp dimmed, our village street lighting is all LED you don't quite need a torch between lamp posts but there dark spots, another plus is there turn off at 00:15, now they need the county council to sort out the main road lighting sodium type that while 1/2 a mile away hidden by tree's they stay on all night when the coast road is deserted.....

[JamesF]

Forgot I had taken this one... This was the "night" after they had done the closest ones to me... Since then the majority of the "sodium" lights visible in the pic have been replaced by LED as well...

That really does look pretty good.

James

[Psychobilly]

That really does look pretty good.

James

If the rain stops I will take another from the same place basically all the lights to the left of centre both the close ones and the ones the other side of the valley are all LED now...

The two lights closest to me are on "blind" bends one on the brow of a hill as well.. it was "interesting" to see how drivers reacted when they were first put in....

Peter...

[Stub Mandrel]

There is one good point made in the article. The strong blue light component in 'white' LED light has a much greater impact on melatonin levels than yellow sodium light does, this will increase it's impact on the biological clocks of animals (including people). I worry about those who stare into phone/computer screens before trying to sleep.... it would be so easy to have an app that gradually reduces the blue component to help you relax before sleep.

It would also be nice if LED manufacturers could reduce the blue component of street lighting.

I never though I would end up missing the power cuts of the 1970s! They must have been amazing for star gazing.

Corollaries to this that shows how light levels can affect wildlife are birds singing in the middle of the night in urban centres and the site that destroys my northerly view with a few thoughtfully positioned powerful sodium lights has some birch trees near a couple of the lights. These two trees don't lose any leaves in a ball some two metres in diameter close to the lights until the new leaves appear in then spring.

[MarsG76]

That will not enlighten any astronomers....

[Stub Mandrel]

OK in plain language, LED lights and staring at your smartphone will help you keep awake all night ;-)

[Psychobilly]

The original image is of the earth surface - the bit he lights are supposed to be illuminating...  More of the light is going where it needs to be...

My personal experience is if you can get above them they are better in dry conditions , If your under them they are worse for you night vision same if you happen to glance at them...

Peter...