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Re: About to take delivery

Posted: Mon Dec 25, 2017 1:48 am
by Jan-hendrik
I've ordered some Philips Xtreme Vision...
The Philips X-treme Vision 3350 are a definite improvement over the standard bulbs.

Re: About to take delivery

Posted: Mon Dec 25, 2017 7:39 am
by White Exec
Christmas lights, Jan. They are good.
Happy Christmas to you!

Re: About to take delivery

Posted: Mon Dec 25, 2017 12:40 pm
by Dieselman
XM dipped beam headlamps are often poor, but with a little effort can be improved noticeably.

Remove the lamp unit and then the glass front and internal lens.

Wash the reflectors, but don't rub them, the sivering is very easily damaged.

Soak the acrilyc lens in bleach for a few days to remove yellowing, then polish up to remove the last remnants.

On rebuilding you will now notice the correct cut off pattern and increased intensity, instead of a diffused light output.

Fitting hotter bulbs isn't really the answer and will cause the lamps to deteriorate more quickly.

Re: About to take delivery

Posted: Mon Dec 25, 2017 8:39 pm
by MTXM
I have bleached and polished the plastic lens in my headlights but the improvement is not hugely noticeable to be honest. My conclusion is that there just is not enough light being produced, mainly due to the relatively small size of the headlight and reflecting area and bulb strength. I am also now going to try the brighter bulbs and hopefully that will help. With regards, Matthew T.

Re: About to take delivery

Posted: Mon Dec 25, 2017 11:10 pm
by Dean
There is the same light being produced as there is in any car headlamp, the trouble is the headlamps are just a bit poor which is why for MK2 vehicles there was a revised design that works, just a shame the RHD market didn't get them.

D

Re: About to take delivery

Posted: Tue Dec 26, 2017 10:30 am
by xmexclusive
There are two problems with XM headlights that I have not seen reported.

Dirt and road film routinely coats the outside of the main glass.
It needs a fairly frequent wipe off.
The Mk2 headlamp washers (even if they work) do not clear reliably.

The rubber seal between the outer glass and the main case does not give a reliable seal.
Neither is the rest of the lamp case air tight.
This can lead to condensation on the inside of the outer glass.
Water droplets here play havoc with the optical path.
Because of the angle of the glass the main effect on the early version glass is to raise the beam angle.
Beam spread is only marginally increased.
This condensation effect is very significant on the later version LHD main glasses.
The water droplets are now formed on the beam diverter pattern which is already much less accurately shaped when cast in glass.
So both beam angle and beam spread are significantly affected while the condensation is present.

John

Re: About to take delivery

Posted: Tue Dec 26, 2017 12:47 pm
by Peter.N.
My last 2.1 was white, I think it suits them too, silver looks nice as well. Looks in pretty good nick, look forward to some more pictures.

Peter

Re: About to take delivery

Posted: Wed Dec 27, 2017 12:31 pm
by MTXM
There is the same light being produced as there is in any car headlamp
I am not sure I agree with you there Dean as the XM headlamp dipped beam housing is really quite tiny compared to modern cars and a lot of the light inner surface is also non-reflective. The dipped beam lens is also about 50% smaller than the high beam that is entirely silvered. In the attached photographs you can see the limited extent of the dipped beam reflection, with the black bare plastic and metal above and below the bulb, while the beam path is also blocked by a small cup that is black painted inside, presumably to further diffuse the light and prevent dazzle? I have tried removing the cup diffuser but rather surprisingly there was little improvement. With regards, Matthew T.

Re: About to take delivery

Posted: Wed Dec 27, 2017 5:23 pm
by djg
Dean must have meant the same bulb used, so the light itself is the same, only that it isn't used as efficiently as in other headlamps.

Re: About to take delivery

Posted: Wed Dec 27, 2017 6:59 pm
by Dieselman
The reflector design isn't the issue. When new, XM headlamps were as good as many others.
Being complex parabolas the reflectors focus the entire light beam forawards, howevert eh plastic lens then reduces output, followed by the glass then reducing it further.

The deteriorration of output is due tot eh silvering becoming cloudy, as a result of dust, oxidysation and mainly, heat. The dipped beam reflectors suffer badly due to the plastic lens causing an encased area, which heats up more than other lamps.

Most modern cars wth halogen lamps use complax parabolic reflectors and a number are now as small in height as those of the XM. The reflectors are now better designed so no longer require a focussing lens.