Light for Glass

Incandescent
The traditional old light bulb or flood lamp using a tungsten or other metal as a filament which is heated to brightness in a vacuum or low pressure non-oxidizing gas. Produces a warm yellowish light that can be adjusted in temperature by changing the voltage.  If the bulb is run at about 10% under rated voltage, it will last several times as long, using more power per lumen - long life bulbs are designed for 130 volts and run at 117 (avg).  Clear glass is commonly better lighted by a whiter light, but yellow or red glass can be enhanced.  Low wattage bulbs are less efficient at making light so  "75-watt incandescent bulb emits approximately 1,190 to 1,220 lumens" [here] and "a typical 25-watt light bulb produces only 210 lumens of light" [here] so 3 25 watt bulbs give 630 lumens vs. about double that for a single 75 watt.

Fluorescent
Light is created when a powder is illuminated by ultraviolet light and gives off white light.  The UV light comes from a glowing plasma created by high voltage inside the tube (or from radio frequency power) which is at low pressure and has a small amount of mercury.  This high voltage is produced by a ballast which also limits current.  Because it is diffused light, the only good uses in lighting glass are reflected lighting off a wall or from underneath. Bottom light is especially nice because they run very cool.  Fluorescent light bulbs come in various colors.  Cool white is the most efficient and is the bright white seen in stores.  Warm white is similar to the color of incandescent.  Daylight is a blue tinted color that matches the light of a clear north sky.  All fluorescent lights are more about five times more efficient than incandescent and most last ten times as long and recently the cost has dropped from about $20 per bulb in the mid 90's to 4 bulbs for under $7.

Halogen
Technically, quartz-halogen.  The quartz is required because the tungsten filament is run at a very high temperature and it heats the tube around it.  Halogen gas (chlorine, bromine, etc.) participates in a chemical reaction where the titanium boiled off the filament and deposited on the quartz is recycled back to the filament.  Thus, a filament that would burn out quickly without the reaction has a reasonable life.

LED
The latest in white lighting is newly available high intensity white Light Emitting Diodes (LED's) which produce light by electron stimulation - sort of like a laser.  In the past, LED's were always colored and generally of low brightness.  High intensity color came first and now by combining colors within the unit, bright white units are available as for flashlights.  LED's run cool and have a long life. As of spring 2008 small devices with batteries and base or solar chargers have come on the market to replace or act as candle like lighting. 32 lumens per watt

Candles
Produce an even warmer light than incandescent at low level but flickering or shifting which can be pleasant.  Produce some smoke and local rising heat and open flame may be a hazard.  Much more on candles is available here.  LED tealights are now available.

Arc
A brilliant white light produced by electricity sparking between electrodes, it is not practical for small scale lighting, but can be used for large scale outdoor lighting - the huge bright spotlights at openings are arc lights and as are old style movie projectors.  Lots of heat is given off and some RF interference.

Area Lighting
Incandescent, fluorescent, and halogen bulbs are used for area lighting as plain bulbs and in flood reflector lights.  Two kinds of bulbs exist that are only suitable for area lighting because of their colors and a variation of one is only used for area lighting because it is so bulky and bright. Each of these bulbs places a glass capsule containing a vapor light source in the center of a bulky glass bulb and all require a ballast in the lamp fixture to start and maintain the light. The required fixtures with a bulb cost $30-90 and up.
High Pressure Sodium creates an arc in sodium vapor that causes the plasma to glow brightly with the yellow color of sodium that glassworkers wear didymium (purple) glasses to see through.  Unlike a spectrum of colors for white light, the light is emitted at very narrow frequencies in the yellow range.  These are the yellow lights of parking lot and street lighting.  The light is very efficient* and the bulbs very long lived but the narrow colors mean that people's pink/red lips look black (no red in the light to reflect) and other colors can't be judged accurately. As with all yellow bulbs, bugs are not attracted.  I have one in my backyard. Emission lines Narrow peaks
Mercury Vapor and Metal Halide bulbs put a small amount of mercury in the capsule.  Mercury vapor bulbs give off a strong blue white light that is harsh on people's skin color and "feels" cool - not warm and friendly.  These are seen in parking lots as more friendly or moonlike than sodium, but car colors may be hard to pick out.  Metal Halide bulbs put a mix of volatile metals with chlorine, bromine or iodine (halides) in the capsule.  These are not as efficient as Sodium or Mercury Vapor lights, but the white light is much more pleasant.  These are used for down lighting in very large spaces like gymnasiums and factories.  The fixtures and bulbs are more costly so these tend to be used in larger sizes and a single bulb would overwhelm a low ceilinged space. 2008-11-06

Element

A heavier resistance wire used for heating, normally glows dull red when hot.

Filament

A thin wire of moderate resistance that becomes hot to give off light when electricity is passed through it.  Element

Lumen

A measure light output. In USA, light bulbs sold retail are supposed to have the lumen printed on the package or as part of the display, so people will buy output rather that "watts" as brightness.

65W OUTDR FLUOR FIXTURE
Lights of America Model: 9165-2
Do it Best SKU: 562416 Online Price: $32.99
Free Shipping: Ship-to-Store, At participating locations, Arrives in 7-10 business days
65W fluorescent yard light, 500 incandescent wattage equivalent. 4500 lumens, 10,000 hours average life. 10.75" H. x 9.87" D. Not for use with dimmer circuits or recessed fixtures. Not recommended for use with timers, photo cells, and motion control devices. Minimum starting temperature is -28 F. White. UL and CSA rated for outdoor (damp) locations. EnergyStar rated. Limited 1 year warranty. Refer to model No. 9166B for replacement bulb. $18.99

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