Our Location

2235 Covington Pike
Memphis TN 38128
Phone: (901) 372-9922
Fax: (901) 372-9969
Email: info@901sounds.net
Mon -Sat 9:00am - 7:00pm
Sunday 11:00am -5:00pm

Fog Lights
A good fog lamp produces a wide, bar-shaped beam of light with a sharp horizontal cutoff (dark above, bright below) at the top of the beam, and minimal upward light above the cutoff. Almost all factory-installed or dealer-optional fog lamps, and a great many aftermarket units, are essentially useless for any purpose, especially for extremely demanding poor-weather driving. Many of them are too small to produce enough light to make a difference, produce beam patterns too narrow to help, lack a sufficiently-sharp cutoff, and throw too much glare light into the eyes of other drivers, no matter how they're aimed.

Good (and legal) fog lamps produce white or Selective Yellow light, and use tungsten-halogen bulbs. Xenon or HID bulbs are inherently unsuitable for use in fog lamps, and blue or other-colored lights are also the wrong choice.

The fog lamps' job is to show you the edges of the road, the lane markings, and the immediate foreground. When used in combination with the headlamps, good fog lamps weight the overall beam pattern towards the foreground so that even though there may be a relatively high level of upward stray light from the headlamps causing glareback from the fog or falling rain or snow, there will be more foreground light than usual without a corresponding increase in upward stray light, giving back some of the vision you lose to precipitation.

When used without headlamps in conditions of extremely poor visibility due to snow, fog or heavy rain, good fog lamps light the foreground and the road edges only, so you can see your way safely at reduced speeds.

In clear conditions, more foreground light is not a good thing, it's a bad thing. Some foreground light is necessary so you can use your peripheral vision to see where you are relative to the road edges, the lane markings and that pothole 10 feet in front of your left wheels. But foreground light is far less safety-critical than light cast well down the road into the distance, because at any significant speed (much above 30 mph), what's in the foreground is too close for you to do much about. If you increase the foreground light, your pupils react to the bright, wide pool of light by constricting, which in turn substantially reduces your distance vision—especially since there's no increase in down-the-road distance light to go along with the increased foreground light. It's insidious, because high levels of foreground light give the illusion, the subjective impression, of comfort and security and "good lighting".