On 06/10/2010 08:44 AM, wrote:
Them bulbs, them bulbs, them dryyy bulbs, doooooo the work of the
Lawd,,,,

And there was Light.
What will Ford Motor Company (Ford has a better Idea, CLICK!) do if
Incandescent Light Bulbs are outlawed in America?
cuhulin

I think they are already on the government's hit list.
Sodium vapor lights? Turn on and wait for ignition???
LED's will probably be packed into a headlight assembly.
I have a 5 year old Cat Eye LED bicycle light that is fair to middling
in the light output category. Newer LED's are brighter but require some
serious heat sinking, something that is do'able in a car for mass
production.
I think they would be more reliable too since I have had one filament
break while the lights were on and I hit a big bump. The filaments are
fairly robust when cold, but very weak when heated to make light.
All 4 now,
Bill Baka

"Bill Baka" wrote in message
...
On 06/10/2010 08:44 AM, wrote:
Them bulbs, them bulbs, them dryyy bulbs, doooooo the work of the
Lawd,,,,

And there was Light.
What will Ford Motor Company (Ford has a better Idea, CLICK!) do if
Incandescent Light Bulbs are outlawed in America?
cuhulin

I think they are already on the government's hit list.
Sodium vapor lights? Turn on and wait for ignition???
LED's will probably be packed into a headlight assembly.
I have a 5 year old Cat Eye LED bicycle light that is fair to middling in
the light output category. Newer LED's are brighter but require some
serious heat sinking, something that is do'able in a car for mass
production.
I think they would be more reliable too since I have had one filament
break while the lights were on and I hit a big bump. The filaments are
fairly robust when cold, but very weak when heated to make light.
All 4 now,
Bill Baka

Our PX has some fancy Samsung LED floods in the parking lot. 75% cheaper to
run than the metal halide lamps they replace, and even a bit more light.

On Jun 11, 1:37*am, "Brenda Ann"
wrote:
"Bill Baka" wrote in message

...





On 06/10/2010 08:44 AM, wrote:
Them bulbs, them bulbs, them dryyy bulbs, doooooo the work of the
Lawd,,,,

And there was Light.
What will Ford Motor Company (Ford has a better Idea, CLICK!) do if
Incandescent Light Bulbs are outlawed in America?
cuhulin

I think they are already on the government's hit list.
Sodium vapor lights? Turn on and wait for ignition???
LED's will probably be packed into a headlight assembly.
I have a 5 year old Cat Eye LED bicycle light that is fair to middling in
the light output category. Newer LED's are brighter but require some
serious heat sinking, something that is do'able in a car for mass
production.
I think they would be more reliable too since I have had one filament
break while the lights were on and I hit a big bump. The filaments are
fairly robust when cold, but very weak when heated to make light.
All 4 now,
Bill Baka

Our PX has some fancy Samsung LED floods in the parking lot. 75% cheaper to
run than the metal halide lamps they replace, and even a bit more light.- Hide quoted text -

- Show quoted text -

So long as they're aimed downward and don't illuminate the night sky
with wasted energy, I am all for them! ;-)

Metal Halide lamps, especially unshielded, are the pits. Brilliant,
sky-obscuring, and hard to overcome with normal amateur filter
equipment.

Bruce the Amateur Astronomer

On Jun 11, 1:40*pm, Bob Dobbs wrote:
bpnjensen wrote:

Metal Halide lamps, especially unshielded, are the pits. *Brilliant,
sky-obscuring, and hard to overcome with normal amateur filter
equipment.

I remember MHs as having a discontinuous spectrum
with about five distinct resonance points
so you would have to combine filtration,
unlike the monochromatic LPS lights.
They probably have some IR and UV too
but I only looked at the visible range in my spectrographic device.

--

Operator Bob
Echo Charlie 42

Thanks for this, Bob. We have filters that can filter out more than
one wavelength, and we can stack filters up to a point - but none that
will cut all five of the spikes, and too many stacked means you also
lose precious desirable light. We also have broader band filters
designed to cut general LP that would probably address all five, but
these filters are also weaker than the stronger line filters. You are
right about LPS, it's a snap to filter - which is why it's been
encouraged for cities near major observatories, such as Lick, Mt.
Wilson (now pretty much useless) and Palomar.

Of course, just as in radio an RF quiet area is best, so in astronomy
nothing beats a good rural or wilderness *dark* sky.

Bruce Jensen
California

bpnjensen wrote:
On Jun 11, 1:40 pm, Bob wrote:
bpnjensen wrote:

Metal Halide lamps, especially unshielded, are the pits. Brilliant,
sky-obscuring, and hard to overcome with normal amateur filter
equipment.

I remember MHs as having a discontinuous spectrum
with about five distinct resonance points
so you would have to combine filtration,
unlike the monochromatic LPS lights.
They probably have some IR and UV too
but I only looked at the visible range in my spectrographic device.

--

Operator Bob
Echo Charlie 42

Thanks for this, Bob. We have filters that can filter out more than
one wavelength, and we can stack filters up to a point - but none that
will cut all five of the spikes, and too many stacked means you also
lose precious desirable light. We also have broader band filters
designed to cut general LP that would probably address all five, but
these filters are also weaker than the stronger line filters. You are
right about LPS, it's a snap to filter - which is why it's been
encouraged for cities near major observatories, such as Lick, Mt.
Wilson (now pretty much useless) and Palomar.

Of course, just as in radio an RF quiet area is best, so in astronomy
nothing beats a good rural or wilderness *dark* sky.

Bruce Jensen
California

As Wilson is primarily a solar observatory these days, I doubt the gas
mixture in the street lamps is very important. I am 18 miles NNW of
Wilson at 1,790', and I can see the Milky Way from my back yard.

On Jun 12, 5:08*am, dave wrote:
bpnjensen wrote:
On Jun 11, 1:40 pm, Bob *wrote:
bpnjensen wrote:

Metal Halide lamps, especially unshielded, are the pits. *Brilliant,
sky-obscuring, and hard to overcome with normal amateur filter
equipment.

I remember MHs as having a discontinuous spectrum
with about five distinct resonance points
so you would have to combine filtration,
unlike the monochromatic LPS lights.
They probably have some IR and UV too
but I only looked at the visible range in my spectrographic device.

--

Operator Bob
Echo Charlie 42

Thanks for this, Bob. *We have filters that can filter out more than
one wavelength, and we can stack filters up to a point - but none that
will cut all five of the spikes, and too many stacked means you also
lose precious desirable light. *We also have broader band filters
designed to cut general LP that would probably address all five, but
these filters are also weaker than the stronger line filters. *You are
right about LPS, it's a snap to filter - which is why it's been
encouraged for cities near major observatories, such as Lick, Mt.
Wilson (now pretty much useless) and Palomar.

Of course, just as in radio an RF quiet area is best, so in astronomy
nothing beats a good rural or wilderness *dark* sky.

Bruce Jensen
California

As Wilson is primarily a solar observatory these days, I doubt the gas
mixture in the street lamps is very important. *I am 18 miles NNW of
Wilson at 1,790', and I can see the Milky Way from my back yard.

That's why it's primarily a solar observatory - the LP from LA has
rendered it useless for dark sky astro. 18 miles can make a big
difference...but it takes a REALLY dark sky for the Milky Way to throw
shadows...

bpnjensen wrote:

On Jun 12, 5:08 am, dave wrote:
bpnjensen wrote:
On Jun 11, 1:40 pm, Bob wrote:
bpnjensen wrote:

Metal Halide lamps, especially unshielded, are the pits. Brilliant,
sky-obscuring, and hard to overcome with normal amateur filter
equipment.

I remember MHs as having a discontinuous spectrum
with about five distinct resonance points
so you would have to combine filtration,
unlike the monochromatic LPS lights.
They probably have some IR and UV too
but I only looked at the visible range in my spectrographic device.

--

Operator Bob
Echo Charlie 42

Thanks for this, Bob. We have filters that can filter out more than
one wavelength, and we can stack filters up to a point - but none that
will cut all five of the spikes, and too many stacked means you also
lose precious desirable light. We also have broader band filters
designed to cut general LP that would probably address all five, but
these filters are also weaker than the stronger line filters. You are
right about LPS, it's a snap to filter - which is why it's been
encouraged for cities near major observatories, such as Lick, Mt.
Wilson (now pretty much useless) and Palomar.

Of course, just as in radio an RF quiet area is best, so in astronomy
nothing beats a good rural or wilderness *dark* sky.

Bruce Jensen
California

As Wilson is primarily a solar observatory these days, I doubt the gas
mixture in the street lamps is very important. I am 18 miles NNW of
Wilson at 1,790', and I can see the Milky Way from my back yard.

That's why it's primarily a solar observatory - the LP from LA has
rendered it useless for dark sky astro. 18 miles can make a big
difference...but it takes a REALLY dark sky for the Milky Way to throw
shadows...

Might it be really dark when Arizona cuts off the juice?

dxAce
Michigan
USA

bpnjensen wrote:
On Jun 12, 5:08 am, wrote:
bpnjensen wrote:
On Jun 11, 1:40 pm, Bob wrote:
bpnjensen wrote:

Metal Halide lamps, especially unshielded, are the pits. Brilliant,
sky-obscuring, and hard to overcome with normal amateur filter
equipment.

I remember MHs as having a discontinuous spectrum
with about five distinct resonance points
so you would have to combine filtration,
unlike the monochromatic LPS lights.
They probably have some IR and UV too
but I only looked at the visible range in my spectrographic device.

--

Operator Bob
Echo Charlie 42

Thanks for this, Bob. We have filters that can filter out more than
one wavelength, and we can stack filters up to a point - but none that
will cut all five of the spikes, and too many stacked means you also
lose precious desirable light. We also have broader band filters
designed to cut general LP that would probably address all five, but
these filters are also weaker than the stronger line filters. You are
right about LPS, it's a snap to filter - which is why it's been
encouraged for cities near major observatories, such as Lick, Mt.
Wilson (now pretty much useless) and Palomar.

Of course, just as in radio an RF quiet area is best, so in astronomy
nothing beats a good rural or wilderness *dark* sky.

Bruce Jensen
California

As Wilson is primarily a solar observatory these days, I doubt the gas
mixture in the street lamps is very important. I am 18 miles NNW of
Wilson at 1,790', and I can see the Milky Way from my back yard.

That's why it's primarily a solar observatory - the LP from LA has
rendered it useless for dark sky astro. 18 miles can make a big
difference...but it takes a REALLY dark sky for the Milky Way to throw
shadows...

It was really bright when I was in BSA.

bpnjensen wrote:
On Jun 12, 5:08 am, wrote:


As Wilson is primarily a solar observatory these days, I doubt the gas
mixture in the street lamps is very important. I am 18 miles NNW of
Wilson at 1,790', and I can see the Milky Way from my back yard.

That's why it's primarily a solar observatory - the LP from LA has
rendered it useless for dark sky astro. 18 miles can make a big
difference...but it takes a REALLY dark sky for the Milky Way to throw
shadows...

As I recall from some hideous PBS in a hotel room, the 100" [?] was too
tiny for anything else, according to the guy who built the 200" on
Palomar. I'm way too busy to look it up.