Date:         Tue, 18 Feb 2003 22:49:56 -0800
Reply-To:     Damon Campbell <damoncampbellvw@YAHOO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Damon Campbell <damoncampbellvw@YAHOO.COM>
Subject:      Re: Those blue xenon HID headlight bulbs all over ebay
Comments: To: Brian Butler <bbutler@PRODIGY.NET>
In-Reply-To:  <20030219063608.54813.qmail@web80202.mail.yahoo.com>
Content-Type: text/plain; charset=us-ascii

Everything i have heard is that they are junk.  Do more harm than good.  A set of e-codes provides good quality light without distracting other drivers (those blue lights are fairly obnoxiously prevalent here in the CA bay area...).  I'll let Daniel Stern do most of the talking:

"Modern methods of obtaining selective-yellow light, such as the placement of a yellow-pass dichroic filter on the bulb envelope, on the reflector or on the lens, can create more problems than they solve. The blue-appearing lenses in many Asian-made fog lamps ("ion crystal", "gold irridium", and other nonsensical marketing names) are coated with a multilayer dichroic interference coating which passes selective-yellow light "on axis", which means "straight ahead". Unfortunately, these coatings tend to glow blue when viewed off-axis, which has caused problems with people getting pulled over for illegal "blue" lights 'cause the cop sees blue.

Many lamps involving dichroic filter coatings on the bulb, reflector or lens tend to create "blue haze" above the beam cutoff or, in the case of a driving or SAE headlamp beam, scattered throughout the beam. That's because of the irridescence of these coatings, which causes or aggravates secondary-reflection problems where none would exist absent the coating. With the mirrorlike dichroic coating reflecting images of the glowing filament, light gets where it doesn't belong. None of these effects help the performance of your lamps at all! Headlamps should be white, and it is best to stick with regular, clear bulbs! Blue light is NEVER used in performance halogen lighting, ONLY in poseur items."

excerpted from: http://lighting.mbz.org/tech/lights/light_color/light_color.html



-damon



 Brian Butler <bbutler@PRODIGY.NET> wrote:Anyone ever try these?
Are they to good/cheap to be true?

Thanks,
Brian

'84 Westy


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