Help Critique My HID Lighting Guide

[Ken_McE]

(Mods, please feel free to move if needed)

Hi folks, I am writing up a laymans guide to HID lighting. It is meant to serve as an available on-line guide for eBayers who want to know a little about this HID stuff. I am assuming they are of ordinary intelligence, have no background in lighting, and could use some very basic information about what this HID stuff is.

My hope is that some of the kindly and wise giants who stride these hallowed forums may care to offer some comments on how I might improve the material below before I post it.

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H.I.D stands for "High Intensity Discharge" These are a family of bulbs that produce light by creating an electrical arc inside the bulb.

What are they good for?

They will produce more light for less electricity than any other kind of bulb. They are naturally bright and powerful and are ideal for lighting large areas. They can also run for thousands of hours with no maintainance, much longer than any incandescent bulb.

What are they bad for?

The bulbs are expensive and need separate (also expensive) ballasts to make them go. You can't just screw them into any lamp and have them go. You can't switch around ballasts between different bulbs. If you are not familiar with electricity you may need to bring in an electrician to do the initial setup.


There are four basic types:

* Low pressure Sodium

Probably the most efficient bulb money can buy. Its main drawback is that it produces an ugly pale orange light. Everything it lights will look pale orange, no matter what its real color is.


* High pressure sodium

Enables you to see a little more color than with low pressure sodium, but at the cost of some efficiency.


* Mercury vapor:

You can see colors, but everything will have a harsh industrial look due to the bluish tint of the light.


* Metal Halide

The least efficient of the HID lights, but has the most natural color. Is still more efficient that any incandescent bulb.


MY HID light is turning on and off by itself.

This means that the bulb is worn out. Just put in a new one and you should be fine.


What about for cars?

This is an interesting subject. Because HID bulbs are so bright, you would think they'd be ideal for cars. The problem is that if they are not installed perfectly you become a public menace. In the US it is illegal to retrofit an HID bulb into a non-HID housing and then drive on a public road with it. If you do, you become a cop magnet because it's such an easy ticket for them. In Europe car manufacturers are required to make any HID headlight self leveling and the housing self cleaning so it cannot refract glare at oncoming drivers.

In the US there are some expensive cars that come with HID headlights. These have a slight bluish color. This has led to a trend where people put bluish lights in their car to make it look fancy. If all you want is bluish headlights, then by all means get them - but don't get real HID bulbs, get an incandescent bulb with a blue tint from any vendor. You'll have the look you want for only a modest cost.

HID conversion kits are worthless unless they include a new lamp housing to replace your stock one. The problem with retrofitting HID bulbs into a housing meant for an incandescent bulb, like a halogen bulb, is that the filament on an incandescent bulb is not the same size and shape as the arc in an HID bulb. HID lights have housings that are specially designed for them. If you somehow squeeze an HID light into a non-HID housing you will get a terrible beam pattern that does not light the road evenly, and does not really help you see better.

If you would like a longer and more detailed explanation of why it is a bad idea to put HID bulbs into a non-HID headlight please see:

http://www.danielsternlighting.com/tech/bulbs/Hid/conversions/conversions.html

 

[brickbat]

"They will produce more light for less electricity than any other kind of bulb"
Not always true. Both linear fluorescent lamps and CFLs are more efficient than some HIDs, such as small MH and almost all MV.

"They can also run for thousands of hours with no maintainance, much longer than any incandescent bulb."
Thousands? Might want to add some numbers here…

"Low pressure Sodium"
I realize wikipedia states otherwise, but you might double check some other sources on the 'fact' about LPS being an HID. It's certainly considered a discharge lamp, but I seem to recall it does not meet the 'high intensity' part.

"ugly pale orange light"
Yeah, I agree, but those are opinions, not necessarily of interest to anyone else. Might be better to say they are near monochromatic and render colors poorly. Ugly, (like beauty) is in the beholder's mind.

"Metal Halide -The least efficient of the HID lights"
Not generally true. Most MH lamps are more efficient than MV.