Clear Lenses - Possible to tune OUT color?

[SteveYem]

I'm sure I'm going against the grain here, but I swapped a set of ZKW-R clear lenses into the OEM E46 style projectors on my Audi S4 and while I really enjoy the sharp cutoff line, I don't really like all of the blue coloration at the cutoff. Sure it looks pretty reflecting off the cars in front of me, but when projected out down the road the color band is thicker and, due to its blue color, not very useful light on the road. Is it possible to tune that blue coloration out of the cutoff line, so that I am left with a sharp cutoff with neutral color?

As it currently sits, I have two(2) #6 flatwashers installed at each mounting point of the lens holder to the projector bowl acting as spacers to make up for the ZKW-R lens not sitting all the way forward in the holder like the OEM lens. In order to tune out the blue coloration, should I be adjusting the number of washers (presumably removing one), or adjusting the cutoff shield fore/aft position with the adjusting screw on the projector, or both? And, is it possible to tune out the blue coloration without decreasing the focus of the light beam and sharpness of the cutoff line?

Side question - I notice that the inverted reflection of my headlights off cars in front of me often appears blue/purple. The color looks like an aftermarket 8000-10000k bulb. Is this reflective color directly related to the blue coloration at the cutoff line, i.e. if I am able to reduce/remove the blue color from the cutoff should this blue/purple reflection phenomenon decrease?

[satrya]

Ideally, if you could move the shield but not the lens relative to the bowl + bulb, it would be ideal. Adding washer in most projectors will likely also move the lens relative to the bowl + bulb. You might find that the beam spread is also slightly altered with the washer approach. It might be small enough to be ok, it might be too large.

Side question - I notice that the inverted reflection of my headlights off cars in front of me often appears blue/purple. The color looks like an aftermarket 8000-10000k bulb. Is this reflective color directly related to the blue coloration at the cutoff line, i.e. if I am able to reduce/remove the blue color from the cutoff should this blue/purple reflection phenomenon decrease?

What do you mean by inverted reflection of headlights off cars? Not the cutoff itself? Or perhaps the foreground limiter's shadow? (if it has one)

[mayurhuria]

E46 has a screw which adjust shield... adjust screw such that the shield moves away from the bowl towards lens... in simple words move shield a bit closer to lens... this will reduce the color... fine tune your setup at 25ft and at 80ft + to gest the right output as per your liking....
Secondly color has nothing to do with intensity of the beam..

[SteveYem]

Ideally, if you could move the shield but not the lens relative to the bowl + bulb, it would be ideal. Adding washer in most projectors will likely also move the lens relative to the bowl + bulb. You might find that the beam spread is also slightly altered with the washer approach. It might be small enough to be ok, it might be too large. What do you mean by inverted reflection of headlights off cars? Not the cutoff itself? Or perhaps the foreground limiter's shadow? (if it has one)

I am now second-guessing whether I should have installed the washers between the lens holder and the projector bowl. The reason I did it was because the lens does not sit all the way into the lens holder like the OEM lens, and the amount that it sits back is approximately the thickness of two #6 washers. However, the 3" ZKW-R lens is also deeper than the OEM lens - 24mm vs. ~22mm if I remember correctly. So I feel like I'm chasing two variables here...

"Inverted" was probably the wrong word to use. I'll describe it instead: often times when I see my headlights reflecting off the bumper of the car in front of me, I also see a second reflection of the lights above on the trunk of the car, and in many cases this 'secondary' reflection shows the light reflecting as a blue/purple color. So what I see reflecting back at me is the white-ish light beam with indigo cutoff line hitting the bumper (with white-ish color focused reflections of the bulbs amongst the light beam), and blue/purple color focused reflections of the bulbs on the trunk (above the cutoff line).
I understand there will always be that second reflection of the headlights, I'm just trying to figure out why it looks so blue/purple and if there is a way to get rid of that.

E46 has a screw which adjust shield... adjust screw such that the shield moves away from the bowl towards lens... in simple words move shield a bit closer to lens... this will reduce the color... fine tune your setup at 25ft and at 80ft + to gest the right output as per your liking.... Secondly color has nothing to do with intensity of the beam..

OK, I will have to play around with that screw some more. I did all of my adjusting at ~20-25ft range and adjusted the shield positions until the cutoff line was as thin and sharp as I could get it, which happened to result in a blue/indigo coloration at the cutoff line. Consequently, this occurred with the shield adjusting screw almost fully backed out, i.e. the shield almost as close to the bowl as possible. When I turned the screw farther in, to move the shield farther from the bowl (closer to the lens), the cutoff line became very blurry and closer to orange/brown in color. Again, this is at 20-25ft range, so maybe the result at longer range for that setting would be more desirable. I will give it a try this weekend.

[satrya]

"Inverted" was probably the wrong word to use. I'll describe it instead: often times when I see my headlights reflecting off the bumper of the car in front of me, I also see a second reflection of the lights above on the trunk of the car, and in many cases this 'secondary' reflection shows the light reflecting as a blue/purple color. So what I see reflecting back at me is the white-ish light beam with indigo cutoff line hitting the bumper (with white-ish color focused reflections of the bulbs amongst the light beam), and blue/purple color focused reflections of the bulbs on the trunk (above the cutoff line).

I think it depends on the curvature of the trunk. If it contains enough of a convex shape, or if the plane of the back side of the trunk is tilted at the right angle, you could be seeing the faint remainder of the cutoff's colorband that wouldn't have been visible via diffuse reflection (i.e. the way the cutoff appears on a matte surface / wall). This would be something closer to specular reflection (i.e. that follows the rule of reflection angle when light hits a mirror).

It is probably more helpful if you have a picture to show; chances are the intensity/contrast may be hard to capture on camera.

[SteveYem]

I think it depends on the curvature of the trunk. If it contains enough of a convex shape, or if the plane of the back side of the trunk is tilted at the right angle, you could be seeing the faint remainder of the cutoff's colorband that wouldn't have been visible via diffuse reflection (i.e. the way the cutoff appears on a matte surface / wall). This would be something closer to specular reflection (i.e. that follows the rule of reflection angle when light hits a mirror). It is probably more helpful if you have a picture to show; chances are the intensity/contrast may be hard to capture on camera.

Agreed, most of the trunks that show this type of reflection are curved/bulged out toward the back, i.e. the convex shape you mentioned.
I will try to grab a photo of it the next time I am sitting in traffic and see it happening.

[mayurhuria]

See the more the shield will be close to bulb the more color... also as I said Tune it at 25ft and also at 80ft... since you have clear lens it will have color be it a little or more... you have to find the sweet spot. Also go with orange soft type cutoff up close will give you sharp at distance..

[SteveYem]

See the more the shield will be close to bulb the more color... also as I said Tune it at 25ft and also at 80ft... since you have clear lens it will have color be it a little or more... you have to find the sweet spot. Also go with orange soft type cutoff up close will give you sharp at distance..

Thanks for that info. It's easy for me to tune at 20-25 ft, in my driveway, but difficult to find a convenient place with level ground and a blank wall at ~80 ft. So I will try adjusting the shield to achieve a softer, orange cutoff and see how it looks in practice on a test drive.