Technical Question About LIDAR, Headlights, and Veil

[JDS]

Technical question for the Veil Guy:

Does LIDAR reflect off of the surface of the headlights, or the reflectors inside? I assume it's the former, but I'm not sure. Or is it both?

[Veil Guy]

The headlight housings of either glass of plastic are primarily transmissive in nature.

Veil Guy

[jdong]

Technical question for the Veil Guy:

Does LIDAR reflect off of the surface of the headlights, or the reflectors inside? I assume it's the former, but I'm not sure. Or is it both?

The inner reflectors are parabolic mirrors that are great at reflecting back light. Of course, if your headlight itself is shiny and reflective (some of them are), then sure it can reflect some LIDAR too.

[insertquarter]

The headlight housings of either glass of plastic are primarily transmissive in nature.

Veil Guy

Sad That I Have 2 Ask Thiz, But in English?

[jdong]

The headlight housings of either glass of plastic are primarily transmissive in nature.

Veil Guy

Sad That I Have 2 Ask Thiz, But in English?

Transmissive: of a transmitting nature.

The clear housing of the headlight primarily lets light, including LIDAR, pass right through it. It neither reflects nor absorbs significantly.

[insertquarter]

Thank u Kind Sir...

[JDS]

Okay, this leads to my second question.

Many people on the VW forums do a "Joey Mod" on their headlights...that is, they black out all the extra shiny parts on the inside of their headlights except for the reflectors themselves. This particularly works with xenon headlights that have more wasted space within the housing, whereas the stock lights take up most of the housing with a large main parabolic reflector.

Would such a modification reduce the range at which LIDAR can get a reading? This assumes a black car with no front plate. In my case, it also assumes VEIL on the headlight housing.

[Veil Guy]

JDS,

Would you provide me with a link or two with a PIC to such a modification?

Veil Guy 8)

[TSi+WRX]

Even the relatively small reflector surfaces behind/within typical "projector" headlamp assemblies - be it HID (aka "Xenon") or traditional incandescent - will reflect visible light to a great degree.

It may not seem so to the naked eye, because of the projector lens being in the way, but a recent set of visible-spectrum pictures by a fellow Subaru owner showed rather shocking reflections from the projector housing of his '06 STI. Search around on this sub-Forum, you should be able to find his post, which also shows his excellent VEIL application technique!

One thing that helped reduce this reflection was the presence of a VEIL-treated "over-lens" that's located farther away from the projector lens. His headlight assembly, which used such a setup, was seen to be much less reflective than that of his fog-lights, for which the over-lens was essentially placed directly above the projector lens, in close proximity.

Exactly how this will translate to the all-critical IR-spectrum, I honestly do NOT know. ops: Hopefully, The Veil Guy can chime-in on this one.

However, I view projector lenses as a liability, particularly if they're "naked."

Thus, even if such blacking-out of the surrounding un-used "cosmetic" reflector elements is accomplished (this is a very, very trendy mod in the Import Sport-Compact community now, BTW) - and even if that does help - the extent to which it helps may still be compromised due to the physical setup of the headlamps.

[holein1]

JDS,

Would you provide me with a link or two with a PIC to such a modification?

Veil Guy 8)

Did a quick google search: http://www.peterbeers.net/vw_roadtri...es/E-Codes.htm