HID Light Bulbs
If you are in the need of a bulb with very high levels of light output, a HID bulb might just be what you're looking for. HID bulbs, or "High-Intensity Discharge" lamps are products with some of the highest levels of light output available. You'll most often find these bulbs light up car parks or warehouses, or being used as car lamps, street lamps and even as security lighting.
HID bulbs are essentially quartz tubes that contain two electrodes and different gas and metal salts that help increase output. With enough voltage an arc of electricity can pass through the gas and metal salts between these two electrodes, which produces light. The secret behind the HID bulbs high light output is how it manages to waste very little heat, meaning that the majority of all that energy is converted into light and not wasted.
The three most common High-Intensity discharge lamps are High Pressure Sodium (HPS), Metal Halide (MH) and Pulse Start.
Metal Halides are usually chosen when color rendering needs to be high. MH bulbs have a higher CRI than the others and can often be used for both indoor and outdoor lighting.
High Pressure Sodium bulbs are the most energy efficient HID bulbs. With a lower CRI, HPS bulbs output large amounts of yellow light. Because of this, these bulbs will usually be used in places where light output is the primary factor.
Pulse Start MH bulbs used Pulse Starts ballasts. This essentially takes a lot of strain off the bulb when starting, which lets the bulb last longer and use up less energy during the initial time of turning on the bulb. The downside to Pulse Start bulbs is the higher price cost, but many find that it pays for itself by the end of the bulbs life time.