Thread: HID H4 headlights

Originally Posted by Tombie

Not true...

Projector type lenses are different, but conventional reflector set ups are used for both source types

This is where the problem lies, good, quality reflectors are different, for a very simple reason. The "arc" on a HID globe runs from the rear of the reflector forward, and is longer than a standard halogen style globes arc. A standard haloden arc goes across the reflector, making focussing between the two very different.

Some manufacturers "cheat" and use the same lens resulting in poor performance, glare issues etc compared with a HID system that was designed from scratch with a HID globe in mind.

At the end of the day in most vehicles a wiring upgrade so the lights get decent power coupled with better quality globes will make a big difference. As a bonus these will improve your lighting on hi and low beam as well as being less of a pain for other road users (assuming they are aimed correclty of course!)

Originally Posted by cookiesa

This is where the problem lies, good, quality reflectors are different, for a very simple reason. The "arc" on a HID globe runs from the rear of the reflector forward, and is longer than a standard halogen style globes arc. A standard haloden arc goes across the reflector, making focusing between the two very different.

Some manufacturers "cheat" and use the same lens resulting in poor performance, glare issues etc compared with a HID system that was designed from scratch with a HID globe in mind.

At the end of the day in most vehicles a wiring upgrade so the lights get decent power coupled with better quality globes will make a big difference. As a bonus these will improve your lighting on hi and low beam as well as being less of a pain for other road users (assuming they are aimed correctly of course!)

This is not where the problem lies at all... Its incorrect...

The Arc is miniscule in its curve (and even a filament style curves a little due to heat)

You are correct in the HID arc is front to rear... But heres the kicker!!!!!

So is a H1, H3, H4 Globe..... (See exhibits below!)



Vs.... A HID globe...


As you can see.. The filaments are aligned F>R in most globes...

The misalignment is in focal point more than anything and between a quality HID and quality Halogen is not really measurable.

Its poor quality HID & Halogen globes which cause all problems... There are more dazzling Halogen headlights out there!!!

Well we will agree to disagree.

The filament length/direction bias are different, and a small change makes a huge difference to focus. Simple as that.

The globes make no difference, could be the worst designed globe, with a reflector that was designed for that specific globes focal point it won't be dazzling or "unfocused at all"

A better designed reflector will make a much bigger difference to the light output than simply increasing the globes output, all things being equal.

Like a lot of things, to improve thingsa and do it right, all the components need to be matched, an off the shelf solution will never provide that as they are manufactured to be middle of the road to "suit" as many applications as possible. This in turn provides volume to reduce the per unit cost, no surprises there.

Smaller runs = more cost, more expensive but better result

Originally Posted by cookiesa

Well we will agree to disagree.

The filament length/direction bias are different, and a small change makes a huge difference to focus. Simple as that.

The globes make no difference, could be the worst designed globe, with a reflector that was designed for that specific globes focal point it won't be dazzling or "unfocused at all"

A better designed reflector will make a much bigger difference to the light output than simply increasing the globes output, all things being equal.

Like a lot of things, to improve thingsa and do it right, all the components need to be matched, an off the shelf solution will never provide that as they are manufactured to be middle of the road to "suit" as many applications as possible. This in turn provides volume to reduce the per unit cost, no surprises there.

Smaller runs = more cost, more expensive but better result

Mate, have you actually tried both types of globes in the same lights in a vehicle yourself ??

I have - and from my experience, what you are saying is simply not true. I can only agree 110% with what Tombie has posted on this.

My D2 has had HID H4 globes fitted for at least three years now - I've generally given up replying to these posts due to the amount of pure ill-informed rubbish that is often posted on them.

Suffice to say that I've never had any type of problem at all since installing them, have never been chatted by the boys in blue though I've been stopped on many occasions for a variety of other reasone, have never once been "flashed" by oncoming traffic (other than on the very first night that they were in there and had not quite been adjusted properly).

Suffice to say that I'm very happy with them - they will stay in the Disco regardless of how many posts I read telling me what a "bad boy" I am - and whatever I buy next will most certainly either have from purchase, or be retro-fitted with HID headlights as well.

I'll agree that there's probably no benefit in installing them if you live in a capital city, and spend most of your night time driving in that environment. But if you live outside of the metropolitan areas and frequently drive on roads where there's plenty to run into, these lights are a godsend.

All of the following is aimed at the LOW beam side of things...

Part of the problem, BMKal, is contained in your signature line... Too many other motorists are ignorant, lazy, have given up, been pinged by coppers for flashing their lights at an idiot on high beam (Said idiot was the copper in my case!) wilfully stupid or blind. Or all of the above!

Try a little experiment, - for those with normal lights... drive around on high beam and see how often you're flashed... Do it in daylight and I'd be surprised if you get more than a couple.

Years ago you'd get flashed ifyou did'nt dip early enough, your lights were out of adjustment, or the boot full of paving slabs (Company cars had infinite load-capacity) Today, rarely.

But, just because the majority of motorists are ... well, lacking something upstairs, it does'nt mean they are'nt adversely affected by glare. They are. Indeed, the light from a HID (OEM or aftermarket) compared to an incandescent of the same lumen/output is 40% greater.

Here's some light reading.... (been itching to use that one )

WebCite query result

- and the WIKI article it came from:-

[ame="http://en.wikipedia.org/wiki/Headlamp"]Headlamp - Wikipedia, the free encyclopedia[/ame]

But for the Time-Constrained, here's the most relevant section,

The traditional European method of achieving low and high beam from a single bulb involves two filaments along the axis of the reflector.

The high beam filament is on the focal point, while the low beam filament is approximately 1 cm forward of the focal point and 3 mm above the axis.

--- Thats the Interesting Bit, as HID's don't quite give the same shape/size/luminous distribution. ---

Below the low beam filament is a cup-shaped shield (called a "Graves Shield") spanning an arc of 165°. When the low beam filament is illuminated, this shield casts a shadow on the corresponding lower area of the reflector, blocking downward light rays that would otherwise strike the reflector and be cast above the horizon.

The bulb is rotated (or "clocked") within the headlamp to position the Graves Shield so as to allow light to strike a 15° wedge of the lower half of the reflector. This is used to create the upsweep or upstep characteristic of ECE low beam light distributions.

But the HID produces a light source that is differant in size/shape/distribution than a filament, - which the reflector & optics are specifically designed for...

- See this link, which pretty well sums it up.

Daniel Stern Lighting Consultancy and Supply

Yes, I've tried the HID mechanically dipping bulb in an Australian-compliant headlamp... brilliant on low beam, even matched the (short-lived) 'Mid beam' pattern... High beam was average.
No matter how low I aimed them, the glare for oncoming motorists was unacceptable compared to the 'Plus-50' halogens.

The WIPAC light distribution is differant from the HELLA units, so this may be working in your favour regarding glare...

I'd still advise staying with incandescent, - 'Plus 100' H4 bulbs are now available for less than the co$t of importing a 'good' HID kit. Upgrade wiring and even the headlamp units.
Cheaper, legal, and IMHO, safer all round as well as better.

There's still a Greenie & Politically-correct bias against 4WD's, so anything that adds to the perception that we're a bunch of Don't Give a Stuff About Your Safety is to be avoided. Blinding them is not a Good Look.

Disclaimer:- I've got 3500K HID's in a Jap import car, in the low beam only. - And I spent a long time carefully aligning the capsules to give the best - safest - beam, which is aligned lower than normal... No Cop has commented. Yet..
.When I can buy H4H's at a sane price I'll do so!

Great research Superquag and convincing enough that I will shelve my tentative plans for HID.
I will keep my HID bulbs in spots however as these are a different issue.
Regards Philip A

When I get an oncoming vehicle with bright lights unless I am absolutly certain that it is high beam I do not flash my lights. Often there is not much difference between a new car on low beam and an old one on high.

So many times I am thinking, is he on high or low. If I get it wrong I then cop a blinding dose of his high beams. I can generally recognise an illegal HID as they are very bright, and as we know the beam is often all over the place.

Flashing them is a waste of time as you only cop it back(probably with the bird as well but can't see it in the dark) and most people who fit these probably don't give a stuff about the other motorist.

Dave.

Its very obvious that my D2 has HIDs... The light assemblies are pure white as you drive towards the vehicle...

However - they will not dazzle you driving towards me...


This is the difference - My HID kit is a very expensive, quality kit...

The H4 bulbs are properly mounted, have the correct range of movement to focus correctly on both low and high - and are consistent in their positioning from low to high, and have a cut off to prevent glaring up into oncoming traffics eyes...

Interestingly lots of people quote the curve of the arc... Poor positioning etc... Its miniscule - and can be adjusted out - not to mention heat (ambient & generated) in both lamp unit and globes of both types will move and influence the positioning of the filament / arc within the reflector.

A filament inside a conventional bulb when on rough terrain moves - wobbles if you will - up and down - you can see it if your eyes are sensitive enough. Cant maintain focus in that condition...


NOW - a basic H4...

I've had a Philips, Narva and Hansa bulb side by side...
All are H4 units
All had different windings on the filament one was 18 coils, another 15 coils and one had 13 coils
A rudimentary measurement shows the start point for the filaments to be varied by 1-3mm between bulbs...

This quite often explains the misalignment often seen in vehicle headlights...

I have no doubt, that ANY bulb not correctly designed, built or 'focused' will perform badly with scattered light everywhere..

But a correctly positioned light source within the same housing will not, can not produce scattered light...

Arguing against HID through and suggesting the +50 and +75 and +100 lights are better is like arguing in the "Does God exist" thread...
The same sources used to shoot down a HID conversion also state that the "Plus Light" globes are a sham.... So make your choice....

Me... Well like BMKal.. I will continue to run them in my vehicle - which has never been flashed... And will no longer be wading into these discussions..