How does the fluted lens affect the light pattern with LED headlights ?
 

The light pattern of a headlight is achieved with the fluted lens . The light bulb is placed in a fixed place in the headlight reflector .
The LED headlights are placed in a different location.
Do the fluted lens scatter the light?

And one more question, there are fluted lenses for left hand drive and for right hand drive.
Do the LED headlights have this function ?

Doesn't you will still get the ___/___/ pattern.

Yes, if you get the adjustable LED's

Caveat, just becareful, wat is stated on the box as far as Lumens is grossly overstated. Lukcky if you get 1800 Lumens

I think it will matter if you are talking about an LED bulb in an H4 headlight or LED projector lights. Two vastly different things.

Edit: This post may help you.

Of course the fluted lens will affect the light pattern. That's what they're designed to do.

However, what they do will likely not be all good. You would probably have the hockey stick shaped pattern. But likely, the edges of the light will have a softer and less controlled direction. "But that's ok, I can still see great and it's better than my old lights." Perhaps this is true. Think of the other drivers on the road. What do THEY see from your lights? Does your excess scatter and glare affect them? Poor conditions such dust and fog can make things worse.

The fresnel lens in the H4 (and other) lights are designed to have the bulb with its light source in a certain spot. This guarantees that the light will be properly refracted through the lens to the desired location. When you mess with those dimensions it kinda mucks things up.

Think of it this way: the globe of an H4 bulb is only just over an inch deep x half that around. The difference between the high beam and low beam filament FITS WITHIN THAT TINY GLOBE. Look at the difference in light direction and placement with just that small difference in filament location. That difference is such that the light emitted travels to a different portion of the lens to be directed at a much different spot on the road. Yes, there is a small difference in power between the two, but that is not what allows you to see so much further on high beam, and when dipped to not blind oncoming drivers.

In addition, it makes a difference what kind of LEDs you are thinking of using. Are they a replacement bulb, projector with DE/poly-ellipsoid lens, headlight replacement like the JE Speaker? All will be affected negatively by an additional fluted lens, just the degree of degradation will change.

Then you ask about left and right hand lenses. YES! It is the lens that directs the light differently to avoid blinding oncoming drivers. If you use an LED, regardless of the type except possibly a headlight bulb replacement, they have their own lensing apparatus. The LHD and RH aspect will be further distorted as the light is in the wrong place for the flutes or fresnel lens to direct it properly. And it would be even worse if a RHD outer lens was used over a LHD LED lens.

If you intend to use some form of LED light "upgrade", it is best to use a clear outer lens if one is required. I know some don't because of aesthetic reasons, and saving a vintage look, but if that is more important than the light output, then it's probably best to stick with H4 or H1 or Cibie or Marchal or any of the plethora of 7" drop in seal beam replacements. They will give a period look and still give outstanding light output.

Kevin,
Thanks for your answer.
Your last comment is what I was thinking, use the LED projectors with a clear outer lens. I think you should not use fluted lenses with LED projectors.
Also I have seen 7" sealed beams or H4 sealed beams, Cibie Z beams behind fluted lenses , which I think you should not do it.

I suppose there are several ways to deal with these cool LED lights. However up here in the NW the sun doesn't go down, in the summer, until after 9:00 and is up by 5:00 so unless you work late or party late you have no use for headlights. For me my cars are pretty much put away for the winter, to much rain, so again headlights? What?

Just my opinion: This driving with headlights in the daytime is just the light manufactures trying to sell more light bulbs.