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Light pollution

 
 
Cynicor
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      09-01-2008
You never realize just how much we're all missing due to that horrible
orange sodium light glow until you get to a dark sky site. I took this
from Montauk NY tonight, looking north across the eastern part of Long
Island Sound. The light in the distance stretches from New London CT to
Providence RI. (This is a fisheye shot turned rectilinear.)

http://trupin.smugmug.com/gallery/16...129_qCraD-A-LB
 
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Robert Coe
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      09-01-2008
On Mon, 01 Sep 2008 00:22:45 -0400, Cynicor <(E-Mail Removed)> wrote:
: You never realize just how much we're all missing due to that horrible
: orange sodium light glow until you get to a dark sky site. I took this
: from Montauk NY tonight, looking north across the eastern part of Long
: Island Sound. The light in the distance stretches from New London CT to
: Providence RI. (This is a fisheye shot turned rectilinear.)
:
: http://trupin.smugmug.com/gallery/16...129_qCraD-A-LB

Sodium lamps radiate at only one wavelength (in the visible spectrum anyway).
So if sodium really is the culprit, you could just Photoshop it out, no?

Or am I (not a PS user) overestimating what PS can do?

Bob
 
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Cynicor
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      09-01-2008
Rita Berkowitz wrote:
> Cynicor wrote:
>
>> You never realize just how much we're all missing due to that horrible
>> orange sodium light glow until you get to a dark sky site. I took this
>> from Montauk NY tonight, looking north across the eastern part of Long
>> Island Sound. The light in the distance stretches from New London CT
>> to Providence RI. (This is a fisheye shot turned rectilinear.)

>
> Oh, I do realize what we are missing as a camping trip to Skyline Drive
> quickly reminds one of the beauty of being above the clouds and
> pollution of
> the city. It is amazing how many stars one can see with the naked eye.


Montauk Point and Blue Ridge Observatory have similar dark-sky profiles.
But the light is encroaching upon Skyline pretty quickly. Montauk is
lucky to have nothing to the south until you hit the Dominican Republic.

Blue Ridge Observatory
http://www.cleardarksky.com/lp/BlRdgOblp.html

Montauk
http://www.cleardarksky.com/lp/MntkPntNYlp.html
 
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Cynicor
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      09-01-2008
http://www.velocityreviews.com/forums/(E-Mail Removed)lid wrote:
> Robert Coe wrote:
>> On Mon, 01 Sep 2008 00:22:45 -0400, Cynicor <(E-Mail Removed)>
>> wrote:
>> : You never realize just how much we're all missing due to that
>> horrible : orange sodium light glow until you get to a dark sky site.
>> I took this : from Montauk NY tonight, looking north across the
>> eastern part of Long : Island Sound. The light in the distance
>> stretches from New London CT to : Providence RI. (This is a fisheye
>> shot turned rectilinear.)
>> : : http://trupin.smugmug.com/gallery/16...129_qCraD-A-LB
>>
>> Sodium lamps radiate at only one wavelength (in the visible spectrum
>> anyway).

>
> Not true. Even low pressure sodium lamps radiate all over the place,
> they just have one wavelength dominant. But almost no place uses
> them. High pressure sodium lamps radiate at all wavelengths. IF you
> can see any color at all (except yellow orange!) in objects illuminated
> by them
> they are broad spectrum.
>
>> So if sodium really is the culprit, you could just Photoshop it out, no?

>
> No. It would be about equally in the R and G channels. You CAN
> however buy filters that remove it (low pressure sodium that is),
> but the resulting colors are not accurate. I have such filters.
> They are useful only for astronomy and oddball artistic effects.


Might I reiterate how much I HATE sodium lighting? When I was a kid, not
THAT long ago, I used to be able to see stars from my home. Now
everything's just a sickly orange twilight. And as you said, it's
impossible to properly color-correct for it.
 
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Craig
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      09-02-2008
On Mon, 01 Sep 2008 10:30:35 -0400, Cynicor wrote:

> (E-Mail Removed)lid wrote:
>> Robert Coe wrote:
>>> On Mon, 01 Sep 2008 00:22:45 -0400, Cynicor <(E-Mail Removed)>
>>> wrote:
>>> : You never realize just how much we're all missing due to that
>>> horrible : orange sodium light glow until you get to a dark sky site.
>>> I took this : from Montauk NY tonight, looking north across the
>>> eastern part of Long : Island Sound. The light in the distance
>>> stretches from New London CT to : Providence RI. (This is a fisheye
>>> shot turned rectilinear.)
>>> : : http://trupin.smugmug.com/gallery/16...129_qCraD-A-LB
>>>
>>> Sodium lamps radiate at only one wavelength (in the visible spectrum
>>> anyway).

<SNIP>
> Might I reiterate how much I HATE sodium lighting? When I was a kid, not
> THAT long ago, I used to be able to see stars from my home. Now
> everything's just a sickly orange twilight. And as you said, it's
> impossible to properly color-correct for it.


Actually it is not Sodium lighting that is responsible for you not being
able to see the stars. It is the cumulative effect of ALL night time
lighting that is not fully shielded to point only down. This includes neon,
white, sodium, mercury etc...

If the lights were truly shielded and properly designed to point down and
not up or to the sides light pollution would be much less. Not totally
gone, since there is still significant relection from the ground upwards.
But then cities, etc... could actually use lower wattage bulbs since the
light goes where it is supposed to and thus save money.

[Getting off my soapbox now]
 
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Cynicor
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      09-02-2008
Craig wrote:
> On Mon, 01 Sep 2008 10:30:35 -0400, Cynicor wrote:
>
>> (E-Mail Removed)lid wrote:
>>> Robert Coe wrote:
>>>> On Mon, 01 Sep 2008 00:22:45 -0400, Cynicor <(E-Mail Removed)>
>>>> wrote:
>>>> : You never realize just how much we're all missing due to that
>>>> horrible : orange sodium light glow until you get to a dark sky site.
>>>> I took this : from Montauk NY tonight, looking north across the
>>>> eastern part of Long : Island Sound. The light in the distance
>>>> stretches from New London CT to : Providence RI. (This is a fisheye
>>>> shot turned rectilinear.)
>>>> : : http://trupin.smugmug.com/gallery/16...129_qCraD-A-LB
>>>>
>>>> Sodium lamps radiate at only one wavelength (in the visible spectrum
>>>> anyway).

> <SNIP>
>> Might I reiterate how much I HATE sodium lighting? When I was a kid, not
>> THAT long ago, I used to be able to see stars from my home. Now
>> everything's just a sickly orange twilight. And as you said, it's
>> impossible to properly color-correct for it.

>
> Actually it is not Sodium lighting that is responsible for you not being
> able to see the stars. It is the cumulative effect of ALL night time
> lighting that is not fully shielded to point only down. This includes neon,
> white, sodium, mercury etc...
>
> If the lights were truly shielded and properly designed to point down and
> not up or to the sides light pollution would be much less. Not totally
> gone, since there is still significant relection from the ground upwards.
> But then cities, etc... could actually use lower wattage bulbs since the
> light goes where it is supposed to and thus save money.
>
> [Getting off my soapbox now]


Out in Montauk (town of East Hampton), they've started requiring
sky-friendly night-lighting. You have to get the shielded lights now for
all new construction.

I've always been annoyed by the light pollution, but even moreso now
that British Sea Power released the brilliant "Lights Out For Darker
Skies" this year.
 
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jaf
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      09-03-2008
http://antwrp.gsfc.nasa.gov/apod/ima...s_dmsp_big.jpg

http://laps.noaa.gov/albers/slides/ast/places_mode3.gif

John


"Cynicor" <(E-Mail Removed)> wrote in message news:48bb6e8a$0$7358$(E-Mail Removed)...
> You never realize just how much we're all missing due to that horrible
> orange sodium light glow until you get to a dark sky site. I took this
> from Montauk NY tonight, looking north across the eastern part of Long
> Island Sound. The light in the distance stretches from New London CT to
> Providence RI. (This is a fisheye shot turned rectilinear.)
>
> http://trupin.smugmug.com/gallery/16...129_qCraD-A-LB

 
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