Terminology: Difference between revisions

;AR coating: anti-reflective coating. A coating on a lens that lets more light through the lens instead of being reflected back towards the light source. See [http://en.wikipedia.org/wiki/Antireflection_coating Wikipedia article]

;aspheric:  a lens designed to offer better throw. "Aspheric" because it does not have the classic lens shape, the shape of the lens is not spherical. This dramatically increases costs. Most affordable ones are injection moulded optical plastic. "Aspheric" means "not a part of a sphere"

;bezel: the front of a flashlight; the part containing/surrounding the lens.

;C: capacity - the charge/discharge rate in an hour. For instance discharging a cell rated 1000mAh at 1C means drawing 1000mA and it should last 1 hour; at 0.1C it would draw 100mA and last 10 hours.

;<span id="CCT">CCT</span>: Correlated Color Temperature, a number in Kelvins that represents color of light. A temperature of 2,700 to 3,000 is warm while while cool colors are 5,000+. See Wikipedia article [http://en.wikipedia.org/wiki/Correlated_color_temperature Color Temperature].

;corona: the area of transition between a beam's central hotspot and the area of spill. The corona becomes more prominent as the reflector surface is made rougher or more heavily textured, and also as the distance of the light emitting surface from the reflector focal point increases.

;<span id="CPF">CPF</span>: [http://candlepowerforums.com/ CandlePower Forums] A large flashlight discussion board and marketplace.

;crenelated: scalloped bezel at the front of a light, to 1) help prevent accidentally leaving the light on when stood on its head; 2) increase utility as a weapon, especially on larger lights (tail is sometimes crenelated too). Sometimes spelled "crenulated."

;driver: the electronics in between the battery and LED. These are usually mounted to a circuit board in the "pill" and regulate the voltage to the LED as well as provide the various modes and memory of the light. See article [[Driver]].

;DX: DealExtreme, a direct ship seller of budget brands of flashlights and parts based in China.

;efficacy: the amount of light output divided by the power consumption. Usually measured in lumens per watt (a watt being volts times amps). For an LED, this value varies with power consumption, becoming less efficient as power increases. Although efficacy is a measure of how efficient an LED is, true "efficiency" would be a percentage calculated by dividing the light output energy divided by the energy consumed.

;<span id="flood">flood</span>: scattered light emitted from a flashlight. Good for indoor use to light up a room or short-range use outdoors to light up an area. Compare with [[#throw|throw]].

;GITD/gid: glow in the dark

;HID: High-Intensity Discharge, a type of bright and efficient lighting.

;hotwire: Generally, a [[Maglite]] that has been modified with special bulbs and batteries to be significantly brighter

;incan: [[Incandescent]]

;KD: KaiDomain, a direct ship seller of budget brands of flashlights and parts based in China.

;LEO: Law Enforcement Officer (these people often carry flashlights)

;LOTC: Lock Out Tail Cap, a type of tailcap (primarily on [[SureFire]] lights) that when pushed slightly, the light will momentarily engage until released.  When pushed harder, the light will engage to constant on until depressed again. The "Lock Out" feature prevents accidental activation by breaking the electrical circuit by separating the tailcap and the conductive body.

;lumens: (abbrev: lm) a measurement of [[Light Output Measurements|light output]]. Lumens measure all of the light output (compare to lux).

;<span id="mAh">mAh</span>: milliampere-hours - a rating of [[battery capacity]] in thousandths of an ampere in an hour. A 1000mAh battery should be able to discharge 1000mA for 1 hour or 500mA for 2 hours.

;Nailbender: a CPF member who makes high power P60 and other drop-ins for host lights.

:2. on conference posts can refer to "original poster," the person who originally started the thread.

;<span id="OTF">OTF</span>: Out-the-front. The amount of light that is actually emitted out of the front of the light, usually measured in lumens. This number is always lower than lumens measured at the emitter (at the LED itself). Some manufacturers quote OTF lumens and others use emitter lumens. Usually the OTF value is around a third less than the rated output of the light-producing device. See [[Light Output Measurements]].

;pill: a housing for the driver and a mounting point for the LED. In smaller lights it is threaded on the outside and screws into the throat of the flashlight body.

;potted: when the pill or electronics of a flashlight are filled or coated with epoxy or other hardening material. The advantage is this prevents corrosion and increases impact resistance since parts can't be dislodged. The disadvantage is it makes any modifications much more difficult.

;<span id="PWM">PWM</span>: Pulse Width Modulation. A technique of varying the brightness of a LED by flashing it on and off very quickly, making it appear to the eye that the LED is dimmer. Good PWM is at such a high rate that you can't notice it. But if you wave your hand in front of the light and get a strobe effect, the PWM is getting too low. Some use current regulation which makes the light dimmer without PWM and is also more efficient.

;regulator: in a flashlight, a circuit that takes energy from a battery and converts it to a (usually) constant current or voltage to feed the flashlight's light element (either an LED or bulb).  Using a regulator, the flashlight's brightness usually stays constant for the majority of the lifetime of the battery, and then output drops quickly and significantly as the battery is no longer able to supply the required energy.  Non-regulated flashlights (also called direct-drive) usually start out at a high output, and then the output diminishes gradually over the lifetime of the battery. See article [[Driver]].

;runtime: a measurement of how long a flashlight will last one a set of batteries of a particular type, usually measured to 50% of the initial output (10% for [[ANSI-NEMA FL-1|ANSI/NEMA FL-1]]). Multi-mode lights have a different runtime for each mode.

;SF: [[SureFire]] or sometimes [[Solarforce]], two flashlight manufacturers.

;<span id="SMO">SMO</span>: a reflector with a smooth finish. Designed for better throw, but also shows imperfections in the LED (e.g. rings). Compare to OP.

;spot: see hotspot

;tactical: more of a marketing term than anything. Often refers to a light with fewer modes and a forward clicky, designed to take some abuse and possibly be mounted to a weapon. See [http://www.candlepowerforums.com/vb/showthread.php?t=147215 CPF discussion].

;<span id="throw">throw</span>: the ability of a flashlight to place light onto a distant defined area of surface, i.e how well the light is collimated. The throw of a light source of fixed power will be defined by the surface brightness of the light emitter, and the shape, diameter, depth, smoothness, and reflective efficiency of the reflector surface. A flashlight with good throw characteristics is called a "thrower" and generally has a narrow beam that is best for illuminating objects at a distance (hundreds of feet). Compare with [[#flood|flood]]. The [[ANSI-NEMA FL-1|ANSI/NEMA FL-1]] standard states throw two ways: candela and meters.

;trit: tritium, a radioactive isotope of hydrogen which emits light. Packed in small vials or cubes, it can be attached to a flashlight so that you can find it in the dark.

;twisty: a method of controlling a flashlight - loosening or tightening the head, control ring, or tailcap turns the light on or off or changes its level or mode. Many lights turn on with the head tightened, but some turn on with the head loosened.

;<span id="UI">UI</span>: user interface. The button presses, head twists, and whatever else is required to operate the flashlight, get to various modes, etc.