There is a new TV ad running for a product called Fast Brite Lens Restore. It's a wax-like cream that is supposed to take your old, fuzzy glaucoma-looking car headlight covers and make them shine brighter. When I saw the ad, something looked fishy in the before and after photos.
Take a closer look and you'll see that the "Before" photo measures the headlight's illumination in LUX and the "After" measures it in footcandles (FC). It's not an apples-to-apples comparison. I noticed this while watching the ad and rewound the ad, froze the frame and took the photo you see here.
What's the difference, you ask? The two headlights aren't being measured by the same standard. I had to look it up. One footcandle equals 10.764 lux. So, the 976 footcandles shown is the same as 90.673 lux, meaning that the "before" headlight is actually brighter than the "after" one. A closer look at the photo and you'll see a "x10" in the middle of the Lux (before) reading. Interesting.
Without going into a lot of explanation, I think you'll see that you shouldn't waste your money on Lens Restore. Instead, you might actually be better off letting your headlights get fuzzy, since they seem to be brighter than a lens with this junk smeared on it. Some reading material for you:
One footcandle ≈ 10.764 lux. The footcandle (or lumen per square foot) is a non-SI unit of illuminance. It is mainly only in common use in the United States, particularly in construction-related engineering and in building codes. Because lux and footcandles are different units of the same quantity, it is perfectly valid to convert footcandles to lux and vice versa.
The name "footcandle" conveys "the illuminance cast on a surface by a one-candela source one foot away." A source that is farther away provides less illumination than one that is close, so one lux is less illuminance than one footcandle. Since illuminance follows the inverse-square law, and since one foot = 0.3048 m, one lux = 0.30482 footcandle ≈ 1/10.764 footcandle.
In practical applications, as when measuring room illumination, it is very difficult to measure illuminance more accurately than ±10%, and for many purposes it is quite sufficient to think of one footcandle as about ten lux.The company's web site proclaims:
There are three main reasons to restore your headlights.
- It will improve your driving visibility and increase safety.
- It is more cost effective to restore them than buying new headlights.
- Third, it's an eye lift for your car! The vehicle will look well taken care of and increase trade in or sales value by hundreds!
In a more practical explanation, a fool and his money are soon parted. I hope my ex-wife is reading this. Moreover, I hope that she has already visited their web site and purchased a large quantity of Lens Restore. I also hope that some consumer-rights advocate has also noticed this and you won't see this ad anymore.
I'd guess that the makers of this automotive snake oil have already made enough money to have moved out of their cushy Suite in Coconut Creek, Florida and onto a brightly lit houseboat floating offshore, with no taxes to pay.