Back at my old club in Boston, someone gave us a talk about the technology of those lamps. In essence, much of the energy is shifted down from near ultraviolet (somehow). The light is quite strong in the blue spectrum, so you have to be very careful if plan on observing. -----Original Message----- From: Chuck Hards <chuckhards@yahoo.com> Sent: May 28, 2004 10:04 AM To: Utah-Astro <utah-astronomy@mailman.xmission.com> Subject: [Utah-astronomy] LED lanterns I finally took the plunge and bought some LED camping lanterns from Sportsmans Guide. They have 2 models, a standard-size lantern with 30 ultra-bright white LEDs, running on D batteries, and a mini size with 12 LEDs, running on AA batteries. Each will run for days and days, continuously, on a single set of batteries. Weeks to months if used intermittantly. They are very bright, comparable to a similarly sized gas-mantle lantern without the combustion byproducts and need for volatile fuel. Plenty of light for those cloudy night activities at the campsite. Now I need take only fossil fuel for cooking needs. I highly recommend these LED-type lanterns over those powered by fossil fuels. I'd even give them an edge over flourescent lanterns due to their smaller power requirements. __________________________________ Do you Yahoo!? Friends. Fun. Try the all-new Yahoo! Messenger. http://messenger.yahoo.com/ _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com
From what I've read, I believe the frequency shift is done by the use of phosphors to cause fluorescence. ---- Jim Cobb james@cobb.name On May 28, 2004, at 10:43 AM, Michael Carnes wrote:
Back at my old club in Boston, someone gave us a talk about the technology of those lamps. In essence, much of the energy is shifted down from near ultraviolet (somehow). The light is quite strong in the blue spectrum, so you have to be very careful if plan on observing.
It's a very common process in many industries, not just plastics. Many materials can be "doped" with "fluors" to either appear brighter (fabrics, papers) or to induce a more drastic wavelength shift. I have a container full of "whitening agent" that glows under UV illumination. I add it to mold release so mold coverage can be checked visually in a darkened room with a black-light. It can be added to paints & varnishes, coatings, etc., to give just about anything a UV response. If anyone remembers the "magic box" solar viewer in S&T a few years ago; I contacted the author of the article and we corresponded about using a doped projection screen to shift the wavelength of the solar image enough to see details normally out of the visual range. Neat idea. Now, as to the lanterns, I did state in my initial post that they best be used on cloudy or moon nights. Obviously noboby needs a bright lantern on a dark-sky night. Many of the new LED flashlights use the same LEDs, so the blue warning applies to them as well. But really, solar exposure near sundown is going to cause you more problems than a few minutes in the presence of a lantern. --- Jim Cobb <james@cobb.name> wrote:
From what I've read, I believe the frequency shift is done by the use of phosphors to cause fluorescence. ---- Jim Cobb james@cobb.name On May 28, 2004, at 10:43 AM, Michael Carnes wrote:
Back at my old club in Boston, someone gave us a talk about the technology of those lamps. In essence, much of the energy is shifted down from near ultraviolet (somehow). The light is quite strong in the blue spectrum, so you have to be very careful if plan on observing.
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Chuck, I've seen lanterns in various camping stores; what did you pay for them? The ones I've seen seemed a little pricey. -Rich --- Chuck Hards <chuckhards@yahoo.com> wrote:
It's a very common process in many industries, not just plastics. Many materials can be "doped" with "fluors" to either appear brighter (fabrics, papers) or to induce a more drastic wavelength shift.
I have a container full of "whitening agent" that glows under UV illumination. I add it to mold release so mold coverage can be checked visually in a darkened room with a black-light.
It can be added to paints & varnishes, coatings, etc., to give just about anything a UV response.
If anyone remembers the "magic box" solar viewer in S&T a few years ago; I contacted the author of the article and we corresponded about using a doped projection screen to shift the wavelength of the solar image enough to see details normally out of the visual range.
Neat idea.
Now, as to the lanterns, I did state in my initial post that they best be used on cloudy or moon nights.
Obviously noboby needs a bright lantern on a dark-sky night.
Many of the new LED flashlights use the same LEDs, so the blue warning applies to them as well. But really, solar exposure near sundown is going to cause you more problems than a few minutes in the presence of a lantern.
--- Jim Cobb <james@cobb.name> wrote:
From what I've read, I believe the frequency shift is done by the use of phosphors to cause fluorescence. ---- Jim Cobb james@cobb.name On May 28, 2004, at 10:43 AM, Michael Carnes wrote:
Back at my old club in Boston, someone gave us a talk about the technology of those lamps. In essence, much of the energy is shifted down from near ultraviolet (somehow). The light is quite strong in the blue spectrum, so you have to be very careful if plan on observing.
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Sportsman's Guide 800-888-5222 www.sportsmansguide.com FX4X-81526 30-LED lantern $39.97 FX4X1-82970 Mini 12-LED lantern $17.97 FX4X1-82969 3 Pc. Mini lantern set $44.97 Add shipping costs. The set of 3 mini's comes in a molded case, as does the single, full-size 30 LED lantern. They also have the mini available individually, I got one for my mom due to semi-regular power outages lately. The 30 LED unit has 2 brightness settings, 15 LEDs, and 30. The 12 LED minis have 4 illumination settings, switch-controlled. These are nowhere near as bright as a gasoline lantern, even the 30 LED lantern produces a much more subtle illumination. Yet it is certainly adequate light for most tasks. Efficiency and safety are bonuses. And what the heck, they're cool. --- Richard Tenney <retenney@yahoo.com> wrote:
Chuck,
I've seen lanterns in various camping stores; what did you pay for them? The ones I've seen seemed a little pricey.
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participants (4)
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Chuck Hards -
Jim Cobb -
Michael Carnes -
Richard Tenney