Multispectral LED lighting is a disaster for amateur astronomers

Martin Brown wrote:
On 05/12/2015 14:41, wrote:
On Saturday, December 5, 2015 at 9:12:43 AM UTC-5, Mike Collins wrote:
wsnell01 wrote:
On Friday, December 4, 2015 at 7:45:28 PM UTC-5, Mike Collins wrote:

The Apple is the LED. The orange is the lp sodium. They aren't the same but
you can see how much brighter and worse shielded the orange is.
There are no locations nearby where you can photograph both of types
together.
You can probably get the camera settings from the image to show that both
were photographed identically.
When you need to compare oranges and apples that's what you do.

Before and after photographs of particular locations are what is needed,
with all other variables controlled. Nothing less will do.



I don't have a time machine.

You do have a time machine:

Take some pictures of LPS/HPS streelights before they are replaced.
Then take pictures under the same conditions after they are replaced.
That would be science.

I probably have some that would qualify although I cannot be certain
that the LED images would be under exactly the same exposure settings
since an automatic exposure would be longer than with the sodium lamps.

The new LED fixtures have a much tighter and less intense light
distribution than either LPS or HPS and nothing above the horizontal.

Take some pictures of the night sky before all of the LPS/HPS streetlights
are replaced, from various locations. Then take pictures of the
night sky
under the same conditions from the same locations after they are
replaced.
That would be science.

And the results are in. It is slightly better with the new lights before
midnight and very significantly better after midnight when they are
switched off. His images are representative of their deployment.

They were manual exposures at the same settings. ISO 3200 0.25 seconds F.5



If anything it exaggerates the glare from the LED fittings since from
above the only thing you see is the stalk near the top of the fixture.

Take some pictures of the night sky, from various locations, after all of
the LPS/HPS streetlights are gone. Then take some pictures of the
night sky
a few years later, from the same locations, when the number of LEDs
(mostly
unshielded and undimmed) has proliferated. That would be science.

The LED fixtures now being sold as insecurity lights are way better than
the horrible 1kW quartz halogen tin cans of old.

If all of that is too much trouble for you, then don't argue with the fact
that there will eventually be FAR more light scattering into the sky and
light pollution will grow substantially worse.

The evidence is stacked against you. The LED lighting is at a lower
level than the LPS or HPS it replaces and much more tightly controlled.
It is also absent entirely after midnight.

It really doesn't get much better than that.

There is a risk that some worried householders will fit their own badly
implemented insecurity lights to compensate for the lack of street
lighting but that is another matter.

Mike Collins wrote:
Martin Brown wrote:
On 05/12/2015 14:41, wrote:
On Saturday, December 5, 2015 at 9:12:43 AM UTC-5, Mike Collins wrote:
wsnell01 wrote:
On Friday, December 4, 2015 at 7:45:28 PM UTC-5, Mike Collins wrote:

The Apple is the LED. The orange is the lp sodium. They aren't the same but
you can see how much brighter and worse shielded the orange is.
There are no locations nearby where you can photograph both of types
together.
You can probably get the camera settings from the image to show that both
were photographed identically.
When you need to compare oranges and apples that's what you do.

Before and after photographs of particular locations are what is needed,
with all other variables controlled. Nothing less will do.



I don't have a time machine.

You do have a time machine:

Take some pictures of LPS/HPS streelights before they are replaced.
Then take pictures under the same conditions after they are replaced.
That would be science.

I probably have some that would qualify although I cannot be certain
that the LED images would be under exactly the same exposure settings
since an automatic exposure would be longer than with the sodium lamps.

The new LED fixtures have a much tighter and less intense light
distribution than either LPS or HPS and nothing above the horizontal.

Take some pictures of the night sky before all of the LPS/HPS streetlights
are replaced, from various locations. Then take pictures of the
night sky
under the same conditions from the same locations after they are
replaced.
That would be science.

And the results are in. It is slightly better with the new lights before
midnight and very significantly better after midnight when they are
switched off. His images are representative of their deployment.

They were manual exposures at the same settings. ISO 3200 0.25 seconds F.5



If anything it exaggerates the glare from the LED fittings since from
above the only thing you see is the stalk near the top of the fixture.

Take some pictures of the night sky, from various locations, after all of
the LPS/HPS streetlights are gone. Then take some pictures of the
night sky
a few years later, from the same locations, when the number of LEDs
(mostly
unshielded and undimmed) has proliferated. That would be science.

The LED fixtures now being sold as insecurity lights are way better than
the horrible 1kW quartz halogen tin cans of old.

If all of that is too much trouble for you, then don't argue with the fact
that there will eventually be FAR more light scattering into the sky and
light pollution will grow substantially worse.

The evidence is stacked against you. The LED lighting is at a lower
level than the LPS or HPS it replaces and much more tightly controlled.
It is also absent entirely after midnight.

It really doesn't get much better than that.

There is a risk that some worried householders will fit their own badly
implemented insecurity lights to compensate for the lack of street
lighting but that is another matter.






Another hit for IOS9 F4.5 autocorrected to F.5

On Sunday, December 6, 2015 at 8:17:07 PM UTC-5, Quadibloc wrote:
On Sunday, December 6, 2015 at 6:00:20 AM UTC-7, wrote:

The Grapes of Wrath is fiction.

That's true. However, many people do feel that Steinbeck's novel accurately
depicted its real-world setting, correctly describing the conditions which
existed in the California grape-farming industry at the time.

Maybe those "many people" should base their opinions of the real-world on something other than a fictional work?

On Monday, December 7, 2015 at 7:06:36 AM UTC-5, Martin Brown wrote:

And the results are in. It is slightly better with the new lights before
midnight and very significantly better after midnight when they are
switched off. His images are representative of their deployment.

You have not presented any results.

The evidence is stacked against you.

You have not presented any evidence.

wrote:
On Sunday, December 6, 2015 at 8:17:07 PM UTC-5, Quadibloc wrote:
On Sunday, December 6, 2015 at 6:00:20 AM UTC-7, wrote:

The Grapes of Wrath is fiction.

That's true. However, many people do feel that Steinbeck's novel accurately
depicted its real-world setting, correctly describing the conditions which
existed in the California grape-farming industry at the time.

Maybe those "many people" should base their opinions of the real-world on
something other than a fictional work?


Many people base their opinions in much worse fictional works eg the bible,
Fox News.

On Tuesday, December 8, 2015 at 7:27:22 AM UTC-5, Mike Collins wrote:
wsnell01 wrote:
On Sunday, December 6, 2015 at 8:17:07 PM UTC-5, Quadibloc wrote:
On Sunday, December 6, 2015 at 6:00:20 AM UTC-7, wrote:

The Grapes of Wrath is fiction.

That's true. However, many people do feel that Steinbeck's novel accurately
depicted its real-world setting, correctly describing the conditions which
existed in the California grape-farming industry at the time.

Maybe those "many people" should base their opinions of the real-world on
something other than a fictional work?


Many people base their opinions in much worse fictional works eg the bible,
Fox News.

I haven't run into any.

wrote:
On Tuesday, December 8, 2015 at 7:27:22 AM UTC-5, Mike Collins wrote:
wsnell01 wrote:
On Sunday, December 6, 2015 at 8:17:07 PM UTC-5, Quadibloc wrote:
On Sunday, December 6, 2015 at 6:00:20 AM UTC-7, wrote:

The Grapes of Wrath is fiction.

That's true. However, many people do feel that Steinbeck's novel accurately
depicted its real-world setting, correctly describing the conditions which
existed in the California grape-farming industry at the time.

Maybe those "many people" should base their opinions of the real-world on
something other than a fictional work?


Many people base their opinions in much worse fictional works eg the bible,
Fox News.

I haven't run into any.



So you've never met anyone who bases their opinions on the Bible?

On Tuesday, December 8, 2015 at 7:41:54 AM UTC-5, Mike Collins wrote:
wsnell01 wrote:
On Tuesday, December 8, 2015 at 7:27:22 AM UTC-5, Mike Collins wrote:
wsnell01 wrote:
On Sunday, December 6, 2015 at 8:17:07 PM UTC-5, Quadibloc wrote:
On Sunday, December 6, 2015 at 6:00:20 AM UTC-7, wrote:

The Grapes of Wrath is fiction.

That's true. However, many people do feel that Steinbeck's novel accurately
depicted its real-world setting, correctly describing the conditions which
existed in the California grape-farming industry at the time.

Maybe those "many people" should base their opinions of the real-world on
something other than a fictional work?


Many people base their opinions in much worse fictional works eg the bible,
Fox News.

I haven't run into any.



So you've never met anyone who bases their opinions on the Bible?

No. Have you?

wrote:
On Tuesday, December 8, 2015 at 7:41:54 AM UTC-5, Mike Collins wrote:
wsnell01 wrote:
On Tuesday, December 8, 2015 at 7:27:22 AM UTC-5, Mike Collins wrote:
wsnell01 wrote:
On Sunday, December 6, 2015 at 8:17:07 PM UTC-5, Quadibloc wrote:
On Sunday, December 6, 2015 at 6:00:20 AM UTC-7, wrote:

The Grapes of Wrath is fiction.

That's true. However, many people do feel that Steinbeck's novel accurately
depicted its real-world setting, correctly describing the conditions which
existed in the California grape-farming industry at the time.

Maybe those "many people" should base their opinions of the real-world on
something other than a fictional work?


Many people base their opinions in much worse fictional works eg the bible,
Fox News.

I haven't run into any.



So you've never met anyone who bases their opinions on the Bible?

No. Have you?


Yes!
And over 58% of Fox News viewers believe that Saddam Hussein was involved
in 9/11.
Fiction!

On Tuesday, December 8, 2015 at 8:08:51 AM UTC-5, Mike Collins wrote:
wsnell01 wrote:
On Tuesday, December 8, 2015 at 7:41:54 AM UTC-5, Mike Collins wrote:
wsnell01 wrote:
On Tuesday, December 8, 2015 at 7:27:22 AM UTC-5, Mike Collins wrote:
wsnell01 wrote:
On Sunday, December 6, 2015 at 8:17:07 PM UTC-5, Quadibloc wrote:
On Sunday, December 6, 2015 at 6:00:20 AM UTC-7, wrote:

The Grapes of Wrath is fiction.

That's true. However, many people do feel that Steinbeck's novel accurately
depicted its real-world setting, correctly describing the conditions which
existed in the California grape-farming industry at the time.

Maybe those "many people" should base their opinions of the real-world on
something other than a fictional work?


Many people base their opinions in much worse fictional works eg the bible,
Fox News.

I haven't run into any.



So you've never met anyone who bases their opinions on the Bible?

No. Have you?


Yes!
And over 58% of Fox News viewers believe that Saddam Hussein was involved
in 9/11.

Do you know all of the them personally?