«Καί αύτη εστίν η επαγγελία ήν ακηκόαμεν απ' αυτού και αναγγέλλομεν υμίν, ότι ο Θεός φώς εστί καί σκοτία εν αυτώ ουκ έστιν ουδεμία» --- α' Ιωάννου 5.
Sir Isaac Newton thought that light was not only a metaphor of God, but instead, God Himself. Light, natural and artificial light sources, were the first things that picked the author's interest when he was 14.
The author's lamp collection follows an appropriate mentality, which has been ingrained to him ever since he was a kid. The author considers most natural and artificial light sources and lamps fascinating and connected in some way to the Divine. Even more interesting the author considers discharge lamps in particular, which generate light by forcing electricity to flow through different element vapors.
There is something totally fascinating about discharge lamps: It's like they offer tangible proof that atoms and electrons exist. One sees the light from the transitions of the electrons from higher to lower energy levels, which is akin to a mini proof of order in physics.
The author's collection is roughly based on different spectra. This is not the entire collection, as the collection includes many duplicates. All of these lamps are functional and most (except the high wattage Compact Source Xenon) have been fired at one time or another using the appropriate support gear. The author did not use a flash when he photographed the collection, to avoid unnecessary reflections on the multiple glass surfaces.
: Mercury/Sodium/Thallium/Indium/Tin Metal Halide HQI-TS 75W/WDL (Warm White Deluxe), in its luminaire, by OSRAM. Spectrum [1.6.2].
: Xenon Stroboscope, in its luminaire. Spectrum [1.12.1].
: Clear High Pressure Mercury Vapor Lamps, including (from top and counterclockwise) a Westinghouse 175W, an actinic PHILIPS HPR 125W, a General Electric 250W, an OSRAM HQA 80W and various quartz discharge tubes from older broken lamps. Spectrum [1.4.1].
: High Pressure Sodium Lamps, including (from top and counterclockwise) a Tungsram 250W, a General Electric 35W, a Sylvania SHP-T 250W and an OSRAM NAV-E 250W, Spectra [1.5.1]-[1.5.2], [1.5.4]-[1.5.5].
: Mercury/Sodium/Thallium/Indium and Mercury/Sodium/Thallium/Dysprosium Metal Halide Lamps, including (from top and counterclockwise) an OY Airam HgA 2000W, a Philips HPI-T 2,000W, a PHILIPS HPI-T 400W, an OSRAM HQI-T/D 400W, 2xTungsram HgMIF 400W, a PHILIPS HPI-T 400W and an OSRAM HQI-T/D 1,000W. Spectra [1.6.1],[1.6.4].
: Mercury/Sodium/Scandium Metal Halide Lamps, including (from top and counterclockwise), a Sylvania 1,000W BD MetalArc, a Sylvania Super MetalArc 175W with Position-Oriented-Mogul Base and a 175W MetalArc with a fluorescent coating. Spectrum [1.6.3]
: Black Light lamps, including (from top to bottom) a PHILIPS High Pressure Mercury blacklight HPW-125W, a fluorescent PHILIPS TL/08 20W, a Sylvania 15W and 8W and a PHILIPS TL-AK/08 4W "blacklight" without Wood's glass. Spectra [1.13.2]-[1.13.4] and [2.1].
: Various incandescent lamps, including (from top and counterclockwise), a PHILIPS PAR 38 100W pressed-glass lamp, an "anti-insect" yellow 100W lamp an "Argenta" 40W lamp, a Kondo-El 1,500W cinema projection lamp, another "Argenta" lamp and a regular clear PHILIPS 200W lamp. Spectra [1.2.2]-[1.2.6].
: Watt-Miser R325W Mercury/Sodium/Scandium Metal Halide from General Electric and Clear High Pressure Mercury Vapor lamp 400W from NORELCO. Spectra [1.4.1] and [1.6.3].
: Carbon rods used with carbon arcs. Top: Plain carbon rods. Bottom, arc beck rods with copper sheathing, and filled with metal salts for cinema projection. Beck rods were used instead of the Compact Source Xenon  until recently for cinema projection. Spectra [1.12.2] and [arc beck].
: Various indicator lights and nightlights, containing neon, argon, krypton and xenon in combination or alone. Spectra [1.9.1]-[1.9.4].
: Various CFL's (Compact Fluorescents), including (from top and counterclockwise) 2 OSRAM 27W, a NARVA 27W and an old PHILIPS SL-18W. The SL was the first CFL in production in Europe and used a magnetic ballast still. Spectra [1.3.3]-[1.3.5].
: Blended light lamps, which use an incandescent filament in series with the lamp to limit the current of the mercury discharge tube, including (from top and counterclockwise) a fluorescent PHILIPS MLR-160W, (which uses a fluorescent coating only on the reflective surface), a fluorescent OSRAM HWL-160W, a fluorescent PHILIPS MLL-160W, the inside frosted (without fluorescent coating), ML-160W and the UV Sun tanning reflector lamp MLU-300W. Spectra [1.4.4]-[1.4.5].
: Compact Source Xenon, 1,600W. This is a beacon lamp, with a luminance of 70,000 cd/cm2! Spectrum [1.12.3].
: Various oddball fluorescents, like the Sylvania GroLux 15W and smaller warm white halophosphate 4W fluorescents. Spectrum for GroLux, [1.3.6]. For the rest [1.3.1]-[1.3.2].
: Assorted High Pressure Mercury Vapor Fluorescent Lamps. These include the reflector PHILIPS HPLR-125W, as well as other types with different fluorescent coatings, such as Magnesium Germanate, Magnesium Arsenate and Yttrium Vanadate, with Wattages ranging from 50W to 250W. Spectra [1.4.2]-[1.4.3].
: General Electric 4W Ozone lamp, which emits germicidal radiation at 254.7nm and at 184.9nm. Small but dangerous to eyes and skin! Spectrum [1.13.1].
: Sylvania's germicidal G8T5 8W. This is essentially how linear fluorescents operate internally, barring the phosphor which is applied on the inside of the glass tube and the material of the glass tube, which on germicidals such as this one allows the 253.7nm radiation through. Spectrum [1.13.1].
: Same as above, but without the background noise, showing the beautiful positive low pressure Mercury column, radiating all the visible and ultraviolet lines of Mercury. Small but also very dangerous to eyes and skin! Spectrum [1.13.1].
[20b]: GE's germicidal G30T8 30W. So dangerous to eyes and skin that a mandatory warning is etched on its surface. Spectrum [1.13.1].
: A Rubidium low pressure lamp from PHILIPS, showing the beautiful purple low pressure column. Spectrum [1.8.2].
: Sylvania's blacklight blue F6T5/BLB 8W fluorescent lamp, showing its purple column and a nearby carton of cigarettes fluorescing under the long wave UV light. Spectra [1.13.2]/[1.11.1].
: 160W blended light lamp by NARVA on a lamp stand illuminating my living room, showing a greenish-white tint with a color temperature of 3,400K and a tiny cold cathode 4,000K USB triphosphor fluorescent illuminating my computer desk. Spectra [1.4.5]/[1.3.4].
: The above blended light lamp in closeup illuminated by a 4,000K triphosphor fluorescent, showing its evacuation tube and the metal strip used to protect the phosphor during evacuation. Spectrum of the illuminator lamp [1.3.4]. Spectrum of the illuminated lamp [1.4.5].
: OSRAM's HQA 80W clear high pressure mercury vapor lamp, showing its very cool, greenish-blue 7,000K temperature light. Spectrum [1.4.1].
: Three different types of illumination, showing the effect of different color temperatures: Far on the lamp stand near my computer desk a cool greenish 125W high pressure mercury lamp with a temperature of 4,700K, in the middle living room daylight fluorescents (not shown) with a cool temperature of 5,500K and close to the camera an incandescent lamp stand with warm color temperature of 2,400K. Spectra [1.4.3]/[1.3.1]/[1.2.2].
: Same setting as above, but this time the lamp on the far lamp stand being a warmer blended light mercury vapor with a temperature of 3,400K, in the middle living room daylight fluorescents (not shown) with a cool temperature of 5,500K and close to the camera an incandescent lamp stand with warm color temperature of 2,400K. Note difference of warmer color of the far lamp stand between this and preceding photo . Spectra [1.4.5]/[1.3.1]/[1.2.2].
: Silverware back illuminated by cool 5,500K regular daylight fluorescents by PHILIPS, TL-D 30W/55. Note how well the cooler tones of these lamps bring out the shine of the silverware which sits behind a brown-tinted glass. Spectrum [1.3.1].
: Kitchen illuminated by four warm 2,700K triphosphor fluorescents by OSRAM, DULUXSTAR 21W/827, showing the very warm color tones of the triphosphor lamps. Spectrum [1.3.3].
: Rubidium spectral lamp from PHILIPS. Spectrum [1.8.2] (*).
: Xenon spectral lamp from PHILIPS. Spectrum [1.8.1] (*).
: Cadmium spectral lamp from PHILIPS, with UV transmitting outer jacket. Spectrum [1.8.3] (*).
: Zinc spectral lamp from PHILIPS, with UV transmitting outer jacket. Spectrum [1.8.4] (*).
: The Rubidium spectral lamp operating. Spectrum [1.8.2] (*).
: The Xenon spectral lamp operating. Spectrum [1.8.1] (*).
: The Cadmium spectral lamp operating. The outer jacket transmits short and longwave UV, so this lamp produces ozone. Dangerous to eyes and skin without sufficient protection! Spectrum [1.8.3] (*).
: The Zinc spectral lamp operating. The outer jacket transmits short and longwave UV, so this lamp produces ozone. Dangerous to eyes and skin without sufficient protection! Spectrum [1.8.4] (*).
: Iron-Cobalt metal halide from PHILIPS, showing the golden plating around the electrodes to raise the arc temperature required to vaporize the metals in it. Can emit large amounts of short and long wave UV, so this lamp is dangerous to eyes and skin! Spectrum [1.6.5] (*).
: Lead-Gallium metal halide lamp from Sylvania. Can emit large amounts of short and long wave UV, so this lamp is dangerous to eyes and skin! Spectrum [1.6.6] (*).
: White Sodium super high pressure lamp from PHILIPS. Spectrum [1.5.6] (*).
: A rare Chinese fluorescent night-light! This is a mini fluorescent light tube at a power of just 1 Watt. Otherwise it is identical to cool/daylight linear fluorescent lamps. Spectrum [1.3.1].
: Same night-light as above, dissected.
: Same night-light as above, dissected and looked upon from a different angle.
: Blue colored metal halide discharge lamp, RADIUM HRI-T 400W/Blau, illuminated by my desktop USB light, showing vacuum getter to the left, quartz discharge tube in the center and support wires on the sides. Spectrum of illuminator lamp: [1.3.4]. Spectrum of illuminated lamp: [1.6.7].
: The discharge tube of the above lamp in close up, showing indium halide traces and mercury inside the tube, tungsten electrodes, molybdenum seals and tube evacuation bubble.
: A short arc xenon lamp, XBO 75W/2, in its lamphouse with power supply and transformer, showing the beautiful daylight color quality of its light. Compare with actual daylight from an overcast day to its left, entering from my living room's window. Spectrum [1.12.3].
: Stereo pair of a close-up of the discharge arc of the short arc xenon lamp, XBO 75W/2,  above, in its lamp house. The positive electrode is up and marked "+". The negative electrode is down and marked "-". The author used two successive green arc-welding filters in front of the projection lens to attenuate the radiation.
: Current configuration for the author's desktop illumination: General space illumination at 3,200K by a small SIGNION duro HIE 70W Kr/Th metal halide (spectrum not recorded yet) on the lamp stand of  (on the left behind not shown), augmented by a small 4,200K, 50W Mercury high pressure lamp on a portable Telco lamp stand to the right (spectrum: [1.4.3]). Typical desktop lamp stand placement should be on the left of reading/writing space, but because of the laptop it is more convenient to place it just above it.
: SIGNION duro HIE 70W Kr/Th metal halide (spectrum [1.6.10]) after ~8K hours and PHILIPS Tungsten Halogen 40W.
: Current total configuration for the author's living room illumination: General space illumination at 4,200K by a small SIGNION duro HIE 70W metal halide  on the lamp stand of , chandelier with Tungsten Halogen 3,100K candle lamps and cloudy day Daylight 6,500K (coming from balcony door), augmented by a small 4,200K, 50W Mercury high pressure lamp of .
(*) Photos by Maxime F. Gendre.
For Color Spectrum photographs of spectra of some of the above lamps taken with a small spectroscope, click here.