On Fri, 2 Jan 2004, John Davies wrote:

> Sorry, this is OT, but I thought some Jeeper in the group might have
> seen these or installed them in his shop or garage.
>
> I am interested in these 175 watt lights. The lowest price I have
> found (US$189 incl 175 watt bulb) is here:
> http://www.griotsgarage.com/search.j...=21&search.y=5

I cannot comment on those specific units, but I can talk a little about
lighting.

As the URL points out, you get a _lot_ more light from a 175 watt metal
halide lamp than you get from an equal wattage incandescent lamp. In an
ideal world you should audition a unit, though, to be sure that the color
rendition is acceptable for what you plan to be doing -- think of those
amber-ish sodium-vapor lights (which you really don't want to use)
commonly used for street lights and what non-color a green car looks like
under them. Keep in mind too that metal halide lamps make light with an
enclosed electric arc and so run significantly hotter than an
equal-wattage incandescent would, so you want to be sure there's room for
some air circulation around them, tucking the head up between two rafters
probably isn't a good idea.

Lastly, there's warm-up time. Enclosed arcs take time (several minutes at
least) to come up to temperature before you get full light output and full
color and every start cycle takes life off the bulb, so it isn't a system
to use if you want instant-on and frequent, short cycles. If that's a
problem, you could install parallel systems, metal halide for extended
shop time and incandescent for finding a screwdriver to fix something in
the house, but that's an increased cost, too.

Someone else in the thread mentioned fluorescents. They're cheap to run,
give good light output for the wattage and run cool, but those who live in
places where it gets cold would do well to spring the extra bucks for
"cold-start" ballasts. The $6 Wall*Mart "shop lights" have a ballast made
out of a choke, a resistor and some chewing gum and once the temperature
gets down to freezing the lights just sputter, hum and glow. Color
rendition can be an issue with flos, too. Cheap tubes have a wicked green
spike in their output and holes in some of the rest of the spectrum. If
color matching is going to be important, spring for the more expensive
"full spectrum" tubes.

Lastly there's shadows. Lamps that have a single point source cast hard
shadows (the smaller the source, the harder and bigger the shadow), so you
want enough incandescents or metal halides ------ around so you get at
least two sources at every work station. Flos are a long narrow source,
so at any given point along the tube your shadow is filled from the light
to your left and to your right. You still get shadows, but they are
softer. You still want multiple, spaced sources, though.

Good luck.

 

On Fri, 2 Jan 2004, John Davies wrote:

> Sorry, this is OT, but I thought some Jeeper in the group might have
> seen these or installed them in his shop or garage.
>
> I am interested in these 175 watt lights. The lowest price I have
> found (US$189 incl 175 watt bulb) is here:
> http://www.griotsgarage.com/search.j...=21&search.y=5

I cannot comment on those specific units, but I can talk a little about
lighting.

As the URL points out, you get a _lot_ more light from a 175 watt metal
halide lamp than you get from an equal wattage incandescent lamp. In an
ideal world you should audition a unit, though, to be sure that the color
rendition is acceptable for what you plan to be doing -- think of those
amber-ish sodium-vapor lights (which you really don't want to use)
commonly used for street lights and what non-color a green car looks like
under them. Keep in mind too that metal halide lamps make light with an
enclosed electric arc and so run significantly hotter than an
equal-wattage incandescent would, so you want to be sure there's room for
some air circulation around them, tucking the head up between two rafters
probably isn't a good idea.

Lastly, there's warm-up time. Enclosed arcs take time (several minutes at
least) to come up to temperature before you get full light output and full
color and every start cycle takes life off the bulb, so it isn't a system
to use if you want instant-on and frequent, short cycles. If that's a
problem, you could install parallel systems, metal halide for extended
shop time and incandescent for finding a screwdriver to fix something in
the house, but that's an increased cost, too.

Someone else in the thread mentioned fluorescents. They're cheap to run,
give good light output for the wattage and run cool, but those who live in
places where it gets cold would do well to spring the extra bucks for
"cold-start" ballasts. The $6 Wall*Mart "shop lights" have a ballast made
out of a choke, a resistor and some chewing gum and once the temperature
gets down to freezing the lights just sputter, hum and glow. Color
rendition can be an issue with flos, too. Cheap tubes have a wicked green
spike in their output and holes in some of the rest of the spectrum. If
color matching is going to be important, spring for the more expensive
"full spectrum" tubes.

Lastly there's shadows. Lamps that have a single point source cast hard
shadows (the smaller the source, the harder and bigger the shadow), so you
want enough incandescents or metal halides ------ around so you get at
least two sources at every work station. Flos are a long narrow source,
so at any given point along the tube your shadow is filled from the light
to your left and to your right. You still get shadows, but they are
softer. You still want multiple, spaced sources, though.

Good luck.

 

On Fri, 2 Jan 2004, John Davies wrote:

> Sorry, this is OT, but I thought some Jeeper in the group might have
> seen these or installed them in his shop or garage.
>
> I am interested in these 175 watt lights. The lowest price I have
> found (US$189 incl 175 watt bulb) is here:
> http://www.griotsgarage.com/search.j...=21&search.y=5

I cannot comment on those specific units, but I can talk a little about
lighting.

As the URL points out, you get a _lot_ more light from a 175 watt metal
halide lamp than you get from an equal wattage incandescent lamp. In an
ideal world you should audition a unit, though, to be sure that the color
rendition is acceptable for what you plan to be doing -- think of those
amber-ish sodium-vapor lights (which you really don't want to use)
commonly used for street lights and what non-color a green car looks like
under them. Keep in mind too that metal halide lamps make light with an
enclosed electric arc and so run significantly hotter than an
equal-wattage incandescent would, so you want to be sure there's room for
some air circulation around them, tucking the head up between two rafters
probably isn't a good idea.

Lastly, there's warm-up time. Enclosed arcs take time (several minutes at
least) to come up to temperature before you get full light output and full
color and every start cycle takes life off the bulb, so it isn't a system
to use if you want instant-on and frequent, short cycles. If that's a
problem, you could install parallel systems, metal halide for extended
shop time and incandescent for finding a screwdriver to fix something in
the house, but that's an increased cost, too.

Someone else in the thread mentioned fluorescents. They're cheap to run,
give good light output for the wattage and run cool, but those who live in
places where it gets cold would do well to spring the extra bucks for
"cold-start" ballasts. The $6 Wall*Mart "shop lights" have a ballast made
out of a choke, a resistor and some chewing gum and once the temperature
gets down to freezing the lights just sputter, hum and glow. Color
rendition can be an issue with flos, too. Cheap tubes have a wicked green
spike in their output and holes in some of the rest of the spectrum. If
color matching is going to be important, spring for the more expensive
"full spectrum" tubes.

Lastly there's shadows. Lamps that have a single point source cast hard
shadows (the smaller the source, the harder and bigger the shadow), so you
want enough incandescents or metal halides ------ around so you get at
least two sources at every work station. Flos are a long narrow source,
so at any given point along the tube your shadow is filled from the light
to your left and to your right. You still get shadows, but they are
softer. You still want multiple, spaced sources, though.

Good luck.

 

>I cannot comment on those specific units, but I can talk a little about
>lighting.
>
>As the URL points out, you get a _lot_ more light from a 175 watt metal
>halide lamp than you get from an equal wattage incandescent lamp. In an
>ideal world you should audition a unit, though, to be sure that the color
>rendition is acceptable for what you plan to be doing -- think of those
>amber-ish sodium-vapor lights (which you really don't want to use)
>commonly used for street lights and what non-color a green car looks like
>under them. Keep in mind too that metal halide lamps make light with an
>enclosed electric arc and so run significantly hotter than an
>equal-wattage incandescent would, so you want to be sure there's room for
>some air circulation around them, tucking the head up between two rafters
>probably isn't a good idea.
>
>Lastly, there's warm-up time. Enclosed arcs take time (several minutes at
>least) to come up to temperature before you get full light output and full
>color and every start cycle takes life off the bulb, so it isn't a system
>to use if you want instant-on and frequent, short cycles. If that's a
>problem, you could install parallel systems, metal halide for extended
>shop time and incandescent for finding a screwdriver to fix something in
>the house, but that's an increased cost, too.
>
>Someone else in the thread mentioned fluorescents. They're cheap to run,
>give good light output for the wattage and run cool, but those who live in
>places where it gets cold would do well to spring the extra bucks for
>"cold-start" ballasts. The $6 Wall*Mart "shop lights" have a ballast made
>out of a choke, a resistor and some chewing gum and once the temperature
>gets down to freezing the lights just sputter, hum and glow. Color
>rendition can be an issue with flos, too. Cheap tubes have a wicked green
>spike in their output and holes in some of the rest of the spectrum. If
>color matching is going to be important, spring for the more expensive
>"full spectrum" tubes.
>
>Lastly there's shadows. Lamps that have a single point source cast hard
>shadows (the smaller the source, the harder and bigger the shadow), so you
>want enough incandescents or metal halides ------ around so you get at
>least two sources at every work station. Flos are a long narrow source,
>so at any given point along the tube your shadow is filled from the light
>to your left and to your right. You still get shadows, but they are
>softer. You still want multiple, spaced sources, though.
>
A few things to add:

"Cold Start" ballasts simply mean that they will start when it gets cold. You
still have a significantly lower light output when the temperature gets below
about 50 or so.

For "low bay" installation like a typical garage, with point source lamps with
diffusers to even out the light somewhat. The tradeoff is that diffusers also
------ light upwards, so you want a light ceiling to minimize loss.

Besides the warm up time, metal halide lamps have what's called a restrike
time, which is the time it takes for them to restart after you've shut them
off. This is typically 5 minutes or longer.

All arc lamps flash on and off rapidly. There are two problems with this:
1. Some peoples eyes become fatigued rapidly by this
2. In a shop, this can lead to an issue called a "strobe effect", where
rotary saws and such can appear to be stationary while they're actually
moving.
Metal halide and sodium lamps are most affected, color corrected mercury and
flourescent (because they have phosphors) are the least. Even a small amount
of suplemental incadescent or natural light will solve these issues.

You get what you pay for with flourescent fixtures. The "professional" grade
have a higher light output than those $10 Home Depot shop lights.

--

Monte Castleman, <<Spamfilter in Use>>
Bloomington, MN to email, remove the "q" from my address

 

>I cannot comment on those specific units, but I can talk a little about
>lighting.
>
>As the URL points out, you get a _lot_ more light from a 175 watt metal
>halide lamp than you get from an equal wattage incandescent lamp. In an
>ideal world you should audition a unit, though, to be sure that the color
>rendition is acceptable for what you plan to be doing -- think of those
>amber-ish sodium-vapor lights (which you really don't want to use)
>commonly used for street lights and what non-color a green car looks like
>under them. Keep in mind too that metal halide lamps make light with an
>enclosed electric arc and so run significantly hotter than an
>equal-wattage incandescent would, so you want to be sure there's room for
>some air circulation around them, tucking the head up between two rafters
>probably isn't a good idea.
>
>Lastly, there's warm-up time. Enclosed arcs take time (several minutes at
>least) to come up to temperature before you get full light output and full
>color and every start cycle takes life off the bulb, so it isn't a system
>to use if you want instant-on and frequent, short cycles. If that's a
>problem, you could install parallel systems, metal halide for extended
>shop time and incandescent for finding a screwdriver to fix something in
>the house, but that's an increased cost, too.
>
>Someone else in the thread mentioned fluorescents. They're cheap to run,
>give good light output for the wattage and run cool, but those who live in
>places where it gets cold would do well to spring the extra bucks for
>"cold-start" ballasts. The $6 Wall*Mart "shop lights" have a ballast made
>out of a choke, a resistor and some chewing gum and once the temperature
>gets down to freezing the lights just sputter, hum and glow. Color
>rendition can be an issue with flos, too. Cheap tubes have a wicked green
>spike in their output and holes in some of the rest of the spectrum. If
>color matching is going to be important, spring for the more expensive
>"full spectrum" tubes.
>
>Lastly there's shadows. Lamps that have a single point source cast hard
>shadows (the smaller the source, the harder and bigger the shadow), so you
>want enough incandescents or metal halides ------ around so you get at
>least two sources at every work station. Flos are a long narrow source,
>so at any given point along the tube your shadow is filled from the light
>to your left and to your right. You still get shadows, but they are
>softer. You still want multiple, spaced sources, though.
>
A few things to add:

"Cold Start" ballasts simply mean that they will start when it gets cold. You
still have a significantly lower light output when the temperature gets below
about 50 or so.

For "low bay" installation like a typical garage, with point source lamps with
diffusers to even out the light somewhat. The tradeoff is that diffusers also
------ light upwards, so you want a light ceiling to minimize loss.

Besides the warm up time, metal halide lamps have what's called a restrike
time, which is the time it takes for them to restart after you've shut them
off. This is typically 5 minutes or longer.

All arc lamps flash on and off rapidly. There are two problems with this:
1. Some peoples eyes become fatigued rapidly by this
2. In a shop, this can lead to an issue called a "strobe effect", where
rotary saws and such can appear to be stationary while they're actually
moving.
Metal halide and sodium lamps are most affected, color corrected mercury and
flourescent (because they have phosphors) are the least. Even a small amount
of suplemental incadescent or natural light will solve these issues.

You get what you pay for with flourescent fixtures. The "professional" grade
have a higher light output than those $10 Home Depot shop lights.

--

Monte Castleman, <<Spamfilter in Use>>
Bloomington, MN to email, remove the "q" from my address

 

>I cannot comment on those specific units, but I can talk a little about
>lighting.
>
>As the URL points out, you get a _lot_ more light from a 175 watt metal
>halide lamp than you get from an equal wattage incandescent lamp. In an
>ideal world you should audition a unit, though, to be sure that the color
>rendition is acceptable for what you plan to be doing -- think of those
>amber-ish sodium-vapor lights (which you really don't want to use)
>commonly used for street lights and what non-color a green car looks like
>under them. Keep in mind too that metal halide lamps make light with an
>enclosed electric arc and so run significantly hotter than an
>equal-wattage incandescent would, so you want to be sure there's room for
>some air circulation around them, tucking the head up between two rafters
>probably isn't a good idea.
>
>Lastly, there's warm-up time. Enclosed arcs take time (several minutes at
>least) to come up to temperature before you get full light output and full
>color and every start cycle takes life off the bulb, so it isn't a system
>to use if you want instant-on and frequent, short cycles. If that's a
>problem, you could install parallel systems, metal halide for extended
>shop time and incandescent for finding a screwdriver to fix something in
>the house, but that's an increased cost, too.
>
>Someone else in the thread mentioned fluorescents. They're cheap to run,
>give good light output for the wattage and run cool, but those who live in
>places where it gets cold would do well to spring the extra bucks for
>"cold-start" ballasts. The $6 Wall*Mart "shop lights" have a ballast made
>out of a choke, a resistor and some chewing gum and once the temperature
>gets down to freezing the lights just sputter, hum and glow. Color
>rendition can be an issue with flos, too. Cheap tubes have a wicked green
>spike in their output and holes in some of the rest of the spectrum. If
>color matching is going to be important, spring for the more expensive
>"full spectrum" tubes.
>
>Lastly there's shadows. Lamps that have a single point source cast hard
>shadows (the smaller the source, the harder and bigger the shadow), so you
>want enough incandescents or metal halides ------ around so you get at
>least two sources at every work station. Flos are a long narrow source,
>so at any given point along the tube your shadow is filled from the light
>to your left and to your right. You still get shadows, but they are
>softer. You still want multiple, spaced sources, though.
>
A few things to add:

"Cold Start" ballasts simply mean that they will start when it gets cold. You
still have a significantly lower light output when the temperature gets below
about 50 or so.

For "low bay" installation like a typical garage, with point source lamps with
diffusers to even out the light somewhat. The tradeoff is that diffusers also
------ light upwards, so you want a light ceiling to minimize loss.

Besides the warm up time, metal halide lamps have what's called a restrike
time, which is the time it takes for them to restart after you've shut them
off. This is typically 5 minutes or longer.

All arc lamps flash on and off rapidly. There are two problems with this:
1. Some peoples eyes become fatigued rapidly by this
2. In a shop, this can lead to an issue called a "strobe effect", where
rotary saws and such can appear to be stationary while they're actually
moving.
Metal halide and sodium lamps are most affected, color corrected mercury and
flourescent (because they have phosphors) are the least. Even a small amount
of suplemental incadescent or natural light will solve these issues.

You get what you pay for with flourescent fixtures. The "professional" grade
have a higher light output than those $10 Home Depot shop lights.

--

Monte Castleman, <<Spamfilter in Use>>
Bloomington, MN to email, remove the "q" from my address

 

i cant comment much abotu room lighting, but i have metal halide lights on my
reef setup and theyre entirely too "sourcy" for a room... long flourescents
cast a nice diffuse light, whereas the halides allow mid-noon type shadows..
very bright and good for stand mount spot lights, but as general room lighting,
i would think of something else first.
-Steve 98 TJ

 

i cant comment much abotu room lighting, but i have metal halide lights on my
reef setup and theyre entirely too "sourcy" for a room... long flourescents
cast a nice diffuse light, whereas the halides allow mid-noon type shadows..
very bright and good for stand mount spot lights, but as general room lighting,
i would think of something else first.
-Steve 98 TJ

 

i cant comment much abotu room lighting, but i have metal halide lights on my
reef setup and theyre entirely too "sourcy" for a room... long flourescents
cast a nice diffuse light, whereas the halides allow mid-noon type shadows..
very bright and good for stand mount spot lights, but as general room lighting,
i would think of something else first.
-Steve 98 TJ

 

Ditto, and for about a tenth of the price.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Goat Crapp wrote:
>
> i cant comment much abotu room lighting, but i have metal halide lights on my
> reef setup and theyre entirely too "sourcy" for a room... long flourescents
> cast a nice diffuse light, whereas the halides allow mid-noon type shadows..
> very bright and good for stand mount spot lights, but as general room lighting,
> i would think of something else first.
> -Steve 98 TJ