Types of Artificial Light Sources
Incandescent:
An incandescent bulb consists of a filament that glows when electricity is passed through it.
| Incandescent Bulb | |
 |
 |
A halogen lamp is a type of incandescent lamp where high-pressure halogen gas is inside the bulb allowing the filament to burn hotter and longer.
| Halogen Lamp | |
 |
 |
Gaseous Discharge
This technology passes electricity through a gas, which excites the gas and causes it to glow. Fluorescent, high-intensity discharge lights (HID) and low-pressure sodium lights use this technology. HID lamps use different gases to produce light:
- Mercury Vapor
- Metal Halide
- High Pressure Sodium
| Metal Halide | Fluorescent Tube | Compact Fluorescent Light |
 |
 |
 |
These types of lights require a ballast, which is a device that starts the lamp and regulates its operation.
| A Ballast |
 |
LED
LED’s are the newest type of artificial light and were born out of the electronics and computer industry. An LED is a tiny electronic device that emits light.
| Red LED | Green LED | Blue LED |
 |
 |
 |
| RGB LED | White LED |
 |
 |
