Lights! (Interesting and Awful please)

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Michel
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Re: Lights! (Interesting and Awful please)

Post by Michel »

CitroJim wrote:
05 Dec 2018, 07:18


It looked almost like an emergency vehicle and could, in poor visibility such as during rain when i saw it, be easily mistaken for one...

Dangerous in my opinion...


Bloody disconcerting when one is trundling along at "motorcycle motorway speeds" at night on the M3, I can tell you. Not so much dangerous as frightening...

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Michel
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Re: Lights! (Interesting and Awful please)

Post by Michel »

van ordinaire wrote:
04 Dec 2018, 23:16
I rather like those Mini lights (unlike the rest of the car, even worse than the original - which I didn't think possible) -


The only problem with the new MINI, is that it's called the MINI. I've driven a few, they're great little cars, especially the Cooper version. Stick to the road like s**t to a blanket, well equipped, nice ride. A really good hot-hatchback. If only BMW had thought to call it something else, and not made it such a retro thing.

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GiveMeABreak
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Re: Lights! (Interesting and Awful please)

Post by GiveMeABreak »

I recall the praises of the XM headlights back in the 90s - this blurb:
Complex surface headlamps consist of a reflector, elliptical in shape, its surface defined point by point (50,000 points) by means of a computer; so that 100% of the light is reflected within the limiting pattern laid down for dipped beams by the regulations. The shape of this complex surface gives much better performance than the conventional metal shades which, even with halogen bulbs, absorb up to 45% of the reflected light. One can therefore say that the complex surface lamp offers 45% better performance than traditional types.
Well that was a disaster, each of my 3 XMs were poor in the lighting dept., with a matchstick providing more light that the headlamps did. On each, the first thing I did was upgrade the bulbs - just to get a half decent amount of light on the road. On my early XM, and before there were many choices for upgrades over the stock bulbs, I did try a 150W bulb as they were so poor - of course on extended use that just blew. That's one thing I didn't miss was dipped beam XM headlamps.

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Michel
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Re: Lights! (Interesting and Awful please)

Post by Michel »

GiveMeABreak wrote:
05 Dec 2018, 10:46
I recall the praises of the XM headlights back in the 90s - this blurb:

Well that was a disaster, each of my 3 XMs were poor in the lighting dept., with a matchstick providing more light that the headlamps did. On each, the first thing I did was upgrade the bulbs - just to get a half decent amount of light on the road. On my early XM, and before there were many choices for upgrades over the stock bulbs, I did try a 150W bulb as they were so poor - of course on extended use that just blew. That's one thing I didn't miss was dipped beam XM headlamps.


I had 3 XMs, an S1, and S1.5 and an S2. The S2 headlights were "acceptable", just.

I picked up the first one one December evening and had to drive it down the motorway home, and I actually pulled over at the first services as I thought the headlights were not working. You can imagine my disappointment when I discovered they were..

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white exec
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Re: Lights! (Interesting and Awful please)

Post by white exec »

Dip on XM was as disppointing as you say - the more so after the marketing hype. Interestingly, main beam (presumably designed by the same process) was (is) extraordinarily good . . . and the contrast between the two is a tad stark.

Was made even worse by RHD vehicles having additional internal plastic fresnel lenses to produce the required dip-to-left beam pattern. The reflectors themselves were identical for LHD/RHD, it was just the addition of the fresnel that sculpted the RHD dip beam, with some minor action by the front glass.

The fresnel also acts as a diffuser, giving an even (but reduced brightness) spread to RHD dip, whereas the headlights without it - I found when I tried it with a brand new LHD pair - gave a bright spot of light from each headlight a short distance in front of the car, and quite poor 'apron' coverage of kerb and road-centre.

The early fresnels yellowed (pale browned, even) with age (action of UV from both sunlight and cheap bulbs) which worsened matters. With effort, they could be cleaned up, just like modern polycarbonate headlights. Later fresnels were made from a different plastic it seems, and tended not to do this. They are now unobtainable new . . . and maybe a project for some 3D printing.

Although intended just for RHD (dip-to-left) use, it was discovered that the plastic fresnels could be flipped, so to as to 'convert' a RHD headlight to LHD. (LHD = smooth side forwards, RHD = smooth side rearwards.)

The patterning on the front glass varies between LHD and RHD versions, but has very limited effect on dip beam compared to the presence (or not) of the fresnel. IIRC, RHD glasses are marked with an arrow pointing left (direction of dip), whereas LHD glasses are 'non-directional', in that the arrow has no head (it's just along dash). See EC headlight markings regs for details.

What I'm running with now (for driving on the right) is a bit of a hybrid arrangement, which I found gives an acceptably bright and certainly even coverage on dip, and avoids the 'two bright spots' mentioned earlier:
- RHD headlight glasses (lines in the glass mitigate the bright spots)
- fresnels in, cleaned, smooth side forwards, for LHD (shape beam, and make it even)
- Nightbreaker or X-treme 55W bulbs

The dipped beam shape is pretty much completely "flat top" without a pronounced kerbside kick-up, so I find it very acceptable for driving on either side of the road. (I do try to keep on one side in any given country, though.)

Not sure how Valeo/Citroen could have got XM dip so absolutely wrong. RHD performance was particularly compromised. Main is fine, as were the extraordinarily good lights on BX. Halving the vertical height didn't help, of course.

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Stickyfinger
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Re: Lights! (Interesting and Awful please)

Post by Stickyfinger »

Xantia S1 cars are equally dangerous when in Dip, dreadful things even when designed for LHD/RHD.

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Michel
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Re: Lights! (Interesting and Awful please)

Post by Michel »

Stickyfinger wrote:
05 Dec 2018, 12:01
Xantia S1 cars are equally dangerous when in Dip, dreadful things even when designed for LHD/RHD.


I never really noticed on my first S1 Xantia, as I was always driving on roads I knew well, and I had it from April to October, so it always went dark late!

The second one, I picked up with DickieG from Jim's and drove home at night. It was shocking! Both of us were surprised. That one got bulbs and the relay mod in double-quick time!

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Stickyfinger
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Re: Lights! (Interesting and Awful please)

Post by Stickyfinger »

Put it this way, in the Activa you have to switch to 1.9D mode at night. The Dip/Main difference is the big problem, to go to zero vision past the on coming car turns every corner into guess work. I hate driving the car at night around pitch dark country roads esp with "modern headlamps" coming the other way.

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Michel
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Re: Lights! (Interesting and Awful please)

Post by Michel »

Stickyfinger wrote:
05 Dec 2018, 14:56
Put it this way, in the Activa you have to switch to 1.9D mode at night.


I recall having a corner surprise me one night in my Activa, for that very reason. At the time, I was also using a Civic Type-R, with superb lights.

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CitroJim
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Re: Lights! (Interesting and Awful please)

Post by CitroJim »

In my experience, XM headlights were so bad as to be dangerous and early (sinker) S1 Xantia nearly so... Later S1 Xantia headlights with the relay mod were almost OK...

All could be improved, to an extent, by fitting high-quality bulbs...

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van ordinaire
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Re: Lights! (Interesting and Awful please)

Post by van ordinaire »

CitroJim wrote:
05 Dec 2018, 08:28
Speaking of indicators, how do some cars get away with very tiny rear indicators? So tiny they're little more than thin slits in the rear-light clusters and almost useless... I've seen cars with bigger side repeaters :twisted:


Curiously the lighting regs do not specify any (minimum) size for indicators - only brightness!

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Paul-R
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Re: Lights! (Interesting and Awful please)

Post by Paul-R »

What happened to the old "must be able to put a (pre-decimal) penny on without overhanging"?

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white exec
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Re: Lights! (Interesting and Awful please)

Post by white exec »

Interesting to hear that Xan I headlights suffered the same as XM on dip.
What was changed when Xan II arrived? Did things improve?

On XM (having just driven back home 20km tonight), kept being reminded that on main beam, not only do you have two very good main beams operating, but dip is on as well - i.e. 4 x 55W on main. Switch to dip, and it's 2 x 55W compromised.

On main beam, the car is night-equipped for extremely high speeds; on dip, it certainly is not.

Idly wonder what would happen if an H4 were installed in place of H1 main...? This, after all, was what BX effectively had.

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GiveMeABreak
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Re: Lights! (Interesting and Awful please)

Post by GiveMeABreak »

Not too much difference visually,
F2C8B121-8723-41DB-9AEF-E9F290A13810.jpeg
13BE352A-7E09-4BB9-B337-D48BCFA11815.jpeg
Xantia S1Xantia S2
I only ever had a Series 2 and found the lights absolutely fine.

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CitroJim
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Re: Lights! (Interesting and Awful please)

Post by CitroJim »

van ordinaire wrote:
05 Dec 2018, 21:40
CitroJim wrote:
05 Dec 2018, 08:28
Speaking of indicators, how do some cars get away with very tiny rear indicators? So tiny they're little more than thin slits in the rear-light clusters and almost useless... I've seen cars with bigger side repeaters :twisted:


Curiously the lighting regs do not specify any (minimum) size for indicators - only brightness!


:shock:
white exec wrote:
05 Dec 2018, 23:05
Interesting to hear that Xan I headlights suffered the same as XM on dip.
What was changed when Xan II arrived? Did things improve?
Chris, early S1 Xantia headlights employed the same basic design and construction as XM lights and thus suffered from the same issues :twisted:

Later S1 Xantia headlights were better but not brilliant... S2 Xantia headlights were a little better again but not brilliant...