Basics

An LED bulb that glows faintly after its wall control is switched off may be responding to a very small current.

An LED can look steady to your eyes while a camera records dark bands or pulsing brightness.

Watts tell you how much electrical power a lamp uses; lumens describe its total visible light output.

Two LED bulbs labeled 3000K can make paint, clothing, and food look different.

A bulb marked dimmable may still stop dimming at a visible level, flicker near the bottom, or switch off abruptly.

An RGB LED strip can look white near its power connection and yellowish, reddish, or dimmer toward the far end.

A water-resistant coating on LED tape does not automatically protect the cut end, connector, controller, or power supply.

Two LED drivers can have similar watt ratings and still be completely unsuitable substitutes.

A brighter LED bulb can fail early inside an unsuitable enclosed fixture even though it uses fewer watts than the old incandescent lamp.

A motion-sensor light that turns on in an apparently empty area may be detecting something outside your assumption of its coverage.