H1vsH4: Hey, Early_S_Man.....
 

Early,
In my previous post re: H1 vs H4 Lens interchangability, you said "H4 lenses, as they are an optical disaster because of the differences in the Fresnel lenses cast into the glass ".
What does that mean....differences in the Fresnel lenses?
Are the H4's beam pattern inferior to the H1's? In what way?


Thanks
MIK

Mik,

No, I didn't mean that the H4 headlamp assemblies with the proper lenses were inferior to H1 assemblies!

What I meant was that the lenses AREN'T interchangeable from an optical standpoint, and if you install H1 lenses on H4 assemblies OR H4 lenses on an H1 headlamp ... what you get are unfocussed beams that aren't useful for driving a 911 at night!!!

<b>In fact, DANGEROUS is what I would call the mismatched headlamp/lens combinations! </b>

I can answer that one. "Fresnel" refers to a pattern moulded or cut in the lens itself. H-4's use one bulb. H-1's use two, placed a bit apart. Therefore, the patterns in each lens is different, to direct the light best from it's location. Different light locations require different lens patterns. To learn more about glass, how light passes through it, visit a lighthouse museum...you'll see some very impressive lenses if you do...Another way to explain it...I'm nearsighted...you're farsighted. Want to trade glasses for a few days?