RRK
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Come across these weird metal halide lamps on the web. Looks like PAR integrated MH with a color filter. What is interesting, have Sylvania used optimized colored MH burners in these, or just off-the-shelf white color burners with a filter? May be James knows?
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RRK
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Found a product catalogue circa 2011. Based on the spectrum published, these are in fact colored burners, not only color filtered. Sylvania made them in RGB and yellow. Really an interesting object for color MH fans
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dor123
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Looks like they uses both colored arctubes and filters. But the yellow lamp seems to have sodium and thallium like the one from BLV, and the red have an impressive sodium and lithium. The green uses thallium, and I don't know what the blue have.
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I"m don't speak English well, and rely on online translating to write in this site. Please forgive me if my choice of my words looks like offensive, while that isn't my intention.
I only working with the international date format (dd.mm.yyyy).
I lives in Israel, which is a 220-240V, 50hz country.
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RRK
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Blue lamp almost certain is indium, plus a little bit of lithium (intended or as an impurity?) and a bit of thermal radiation in red. So it in fact is some kind of bluish purple, still pretty, as all usual yellow-greens of a blue MH are filtered out.
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« Last Edit: April 06, 2023, 12:02:54 PM by RRK »
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dor123
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The emission in the spectrum of the blue lamp, don't looks indium to me.
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I"m don't speak English well, and rely on online translating to write in this site. Please forgive me if my choice of my words looks like offensive, while that isn't my intention.
I only working with the international date format (dd.mm.yyyy).
I lives in Israel, which is a 220-240V, 50hz country.
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RRK
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Sylvania's spectrum scales seems to be off. For Thallium, green peak shall be at 535nm, but it does not look so. For Indium, two strong lines shall be 410 and 451nm, seems to be off too. Whoever did this catalog thought readers will be too lazy to catch them for sloppiness. )
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HomeBrewLamps
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Why does the thermal spike seem so small in the green lamp compared to the others?
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~Owen
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Max
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Those colored BrightSpots are interesting little lamps. You can find detailed spectral characteristics of different models in my lamp spectra folder. It appears that those lamps have a white-light burner and a dichroic front window. @RRK - The spectra published by Sylvania are not off. The blue lamp does not contain indium and the prominent line around 510 nm from the green lamp is not from thallium but from scandium.
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RRK
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Yep. Thanks. The spectrum tells it all. Technically, a bit disappointing. They absolutely did not want to mess with the established fill chemistry and just reused off-the-shelf burners with off-the-shelf MR capsule filter glass. That means their blue lamp is not very bright in fact, because the original Na-Sc burner is not particularly rich in blue-violet area.... No wonder these got killed-off by modern blue led chips (>50% conversion efficiency and no messy high-voltage electronics) without any mercy....
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« Last Edit: April 06, 2023, 09:04:05 PM by RRK »
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James
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These all use a hybrid arc tube chemistry of Dy-Ho-Tm-Sc-Na-Li. In some lamps of later production the Na:Re ratio is different for the green and blue vs red and yellow. The former deliver about 6000K without the dichroic filter front lens, the latter about 3000K. This helped the blue and red versions to achieve much higher brightness than if all were made with eg 4000K arc tubes. It was sometimes objectionable with the earlier lamps that the green and yellow appeared significantly brighter
The Sylvania catalogue is certainly not off in terms of specs. Since about 2005 it became part of the job of my department to edit these each year to ensure absolute technical accuracy. But even before that they were rather accurate, although occasionally a little thin on some technical specifications.
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RRK
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It was just my wrong assumption, that what we see on the diagram for the blue lamp is two peaks of indium, somewhat shifted ~ 30nm in the publishing process. Well, in fact things are quite different with this lamp.
By the way - do you know why Sylvania ended up with such complicated hybrid chemistry for Britespot burners? Adding scandium to RE will (at the first sight) decrease the light quality a bit because of adding some discrete spectral peaks?
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« Last Edit: April 08, 2023, 01:26:33 AM by RRK »
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