Are these lights ready for the trash?

[-Virgil-]

I notice that there are untinted Sylvania Silver stars for sale at Wal-Mart.

No, there aren't any untinted Sylvania Silver Star bulbs. The ones you are pointing at as "untinted" actually have a blue tint to the entire glass capsule. It's not as dark a blue, but it is definitely there, without any untinted bands or gaps. And no, they are not better than the Xtravisions.

 

[-Virgil-]

The zXe Gold ones, if I could suspend my disbelief that they'd really be any good, has very carefully deposited (or laser-ablated), and fairly deep blue, tinting with distinct windows to the filament.

Looks like an American-market version of the Osram Night Breaker Laser bulbs, which don't seem to live up to the hype used to market them.

(It would be nice if any of the banded bulbs used a yellow tint instead of blue

Those exist (Sylvania Fog Vision)

 

[Alaric Darconville]

It would be nice if any of the banded bulbs used a yellow tint instead of blue

Those exist (Sylvania Fog Vision)

Oh, but not quite! This is tinting the light in the main beam, and light outside the main beam is untinted. I'd like to see the yellow bands placed such as where the blue ones are used, so that maximum output is within legal limits, light outside the main beam tends much more towards yellow than blue, and the main beam is still untinted.

This is just a very crude mockup:

 

[-Virgil-]

Oh, I see what you mean.

H'mmm. Interesting idea: It might turn some of the stray light outside the beam pattern yellow, depending on the paths of the stray light rays within the headlamp. I'm not sure how much benefit, if any, would result. Also, yellow tinting isn't as effective as blue for blocking light to "artificially" depress the output reading in the integrating sphere, so the beam performance wouldn't be as effective.

I wonder what would happen with a non-blue, non-yellow, non-any-other-color mask for that purpose. Photographers call it "neutral density" filtration: it reduces light without tinting it, so it looks gray.

 

[Alaric Darconville]

H'mmm. Interesting idea: It might turn some of the stray light outside the beam pattern yellow, depending on the paths of the stray light rays within the headlamp. I'm not sure how much benefit, if any, would result.

It would look less "cool" but also be less glaring than blue.

Also, yellow tinting isn't as effective as blue for blocking light to "artificially" depress the output reading in the integrating sphere, so the beam performance wouldn't be as effective.

Depth of tint would certainly be a factor, but maybe too deep and it would lead to excessive heating of the envelope.

I wonder what would happen with a non-blue, non-yellow, non-any-other-color mask for that purpose. Photographers call it "neutral density" filtration: it reduces light without tinting it, so it looks gray.

Or yellow-gray, even (which has color, yes, but a benign one). That would increase the transparency and reduce envelope heating a little.
It could be a problem the bulbmakers have worked on already.

 

[Ls400]

Why not try this?

https://www.danielsternlighting.com/tech/lights/light_color/light_color.html

He suggests taping the lens of a headlamp with this:

https://www.amazon.com/dp/B007GCNAB6/?tag=cpf0b6-20

Or spraying it with this:

https://www.amazon.com/dp/B000994BUW/?tag=cpf0b6-20

Perhaps a selective tint of the outermost lens would achieve the same effect?

Isn't the upper rear portion of a reflector headlamp responsible for distance vision? With that in mind, perhaps one could selectively tint parts of the outer lens through which most of the light responsible for distance vision does not travel?

 

[Alaric Darconville]

Why not try this?

Taping the lens of the headlamp in such a way that the light in the main part of the beam is uncolored, and the light outside of the main part of the beam is uncolored, is much more difficult than you might think.

Or spraying it with this:

Again, it's more complicated than you might think. The lens has a (typically) convex shape, and there's a reflector behind it with a complex or semi-complex surface. Some headamp lenses have fluting and cuts in them to manage the beam. Determining the exact spots to color would be a very complicated thing indeed.

Isn't the upper rear portion of a reflector headlamp responsible for distance vision?

Taking a sealed beam lamp as an example, the main (high) filament is placed in the center of the unit, the low beam filament is placed higher, and sometimes is even a bit rearward. More of its light hits the top of the reflector, which then directs it downward. For headlamps using the HB2, the low beam filament is forward of the high beam filament, so it too is in a different focal point. Often, you'll see a car using its low beams and it appears that the top half of the reflector is lit up more than the bottom half.

Consider if the light were bouncing off the bottom half of the reflector-- it'd then bounce upward.

And so if you were to carefully mask everything off so it would have the desired effect on the low beam, it'd be vastly different if you switched to high beams on a single-compartment high/low beam headlamp.

However, if you do all the appropriate tinting on the bulb itself (as has been done with the high-performance halogen bulbs that use the blue banding) then it would work all the time, in any lamp that accepted the bulb type.

Now, if I wanted ALL the light leaving my headlamp to be yellow, sure, I could tape it/paint it. But that's not what I want.

 

[-Virgil-]

Isn't the upper rear portion of a reflector headlamp responsible for distance vision?

No. It is not possible to generalize like this.

 

[Ls400]

I wonder what would happen with a non-blue, non-yellow, non-any-other-color mask for that purpose. Photographers call it "neutral density" filtration: it reduces light without tinting it, so it looks gray.

What are your thoughts about the Lunex H9+80 bulbs? They have something akin to a neutral density filter, I think. They have what's apparently called an interference coating. The coating isn't colored, but it reduces light output while shifting the color temperature. It's been a while since I picked up a camera, but I don't think ND filters change color temperature. I read about them here:

https://www.tacomaworld.com/threads...11-projector-headlights.589465/#post-19689311

There are apparently other interference coated bulbs on the market, but there's 0 discussion about them here! What gives?

 

[-Virgil-]

They have something akin to a neutral density filter, I think. They have what's apparently called an interference coating. It's been a while since I picked up a camera, but I don't think ND filters change color temperature.

A neutral density filter is an absorption filter that looks gray to black, and it seems like you already know this. Those bulbs have nothing at all like a neutral density filter.

The coating isn't colored, but it reduces light output while shifting the color temperature.

This sentence is self-contradicting. Set in simpler words, it says "The filter isn't colored, but it's colored". There's no such thing.

There has been plenty of discussion on here about interference-coated bulbs. Search for the word "dichroic". Another synonymous term is "multilayer". It's a terrible idea. If you want to read in technical detail about the problems it causes, you could pay a ridiculous amount of money to SAE for J2739. In a nutshell: the irridescence of the coating causes a bunch of random stray light due to recursive reflections that aren't supposed to be there. This, in turn, reduces seeing light and increases glare light coming out of the headlamp. There's color blotching within and outside the beam. A yellow-pass coating like the ones on those "Lunex" bulbs causes blue haze outside the beam, including above the cutoff of a low beam.

And as far as "Lunex" goes: just another of the many, many varieties of off-brand/non-brand garbage. Take a look at their pathetic website (it'll take you awhile to find...oddly enough). On their "About" page you can read, in broken and defective English probably generated with the aid of something like Google Translate, about their "reliable approved CE automotive bulbs, with innovative xenon and halogen technology, as a result gained from our years of experience on lighting market". Oh yeah, they totally sound British...not! There is no such thing as a CE-approved automotive bulb (let alone an "approved CE" one). There is no innovative technology in what they are offering. The thing about "years of experience" is an outright lie. And contrary to the baseless claim made by the dude claiming (dubiously) to be an engineer in that thread you linked, halogen bulbs for cars haven't been manufactured in the UK for decades. The entire "Lunex" product line is run-of-the-bog generic Chinese junk, boxed up and named and marketed the same as dozens and dozens of other con artists do, even using the same bag of words ("plasma", "platinum", "supreme", etc). These are the exact bulbs found at booth after booth in the China pavilions at the auto parts industry trade shows. They'll brand and package 'em however you want, if you buy enough of 'em.

Again (and again, and again because apparently it can't be said often enough): There are few enough legitimate, reputable brands that it's not hard to keep 'em all in mind. Bulbs that don't come from one of them are not worth using. That holds true no matter what BS claims are on the packaging or in the advertising, and no matter what nonsense gets whipped up out of ignorance and wishful thinking and religious faith and sponsorship and quasi-science on forums like the one you linked to. Please let's not get into an endless loop of the same discussion about the same junk over and over, like "What about these [off brand] bulbs? What about these the dude at the stereo and window tint shop sells? What about these they're talking about over on FordsRule.com? What about these I saw on ebay?".