I noticed the headlights don’t seem to be as bright as they once were, are my eyes getting old, was it the road i happened to be on or do the halogens lose lumen output when they age?
Also the headlights are beginning to frost on the edges over the blinkers but perhaps the rest had frosted imperceptibly?
They are supposed to keep 95% of their brightness until they die. So it’s likely your lenses or whatever they call them need to be cleaned up.
Yes, but there are other things that can cause that. Have you noticed any hair growing on your palms? J)
not since i used the laser from inside the dvd player to zap everything in sight
Something I notice that stands out ALOT: if I use my J18 or any other big output light and then get in the car soon afterwards, my headlights look like dim puny lights. I’ve hiked back to my car in the darkness while using my lights and then when I get in the car and start up it feels like I cant see half what I could compared to before and I feel like shining my light out the window. Maybe that’s whats happening to you. 
Here is some interesting reading:
http://donklipstein.com/bulb1.html
From what I gather after scouring the web, halogen bulbs do lose brightness with age, but not nearly as much as standard incandescent bulbs do. In fact that’s basically one of two big features of halogen, along with a longer life span.
Does that actually work?
With some modding yes. I think it’s infrared laserlight though so you wouldn’t see the light anyway except with some night vision equipment.
thats awesome, i always assumed it was a red light (must have seen some videos of lasers and CDs and an all)
With light stuff i post here then check google if needed, i found conflicting information, one source says less then 10% loss over the lifetime, anther one said it can be significant.
I have an old car (Lexus from 96) and the lights on it are VERY dim. Reading this now makes me want to try out putting some new bulbs in it…. I’ll post if there will be any difference.
I read somewhere that tungsten is deposited on the quartz envelope when the bulb is undervolted—the lower operating temperature makes the halogen cycle less effective at reconstituting the filament with evaporated tungsten. Something like that?
bulb filament degrade - I saw some halogen bulbs that black filament and looks like wear out. And reduced current draw than rated (increased filament resistance)
how about these:
Reflector degrade
front plastic degrade (UV damage??)
bulb,switch contact oxidize and then increased resistance
Wow!!! Do you know any sites with instructions I can make something? That would be so cool (and save so much!!).
It’s a double whammy! Light output exponentially as the lamp voltage drops (I don’t remember the exponent) and the low voltage/reduced temperature stop the halogen cycle from working. The light can get dim rather fast.
Another little gotcha with running incandescent bulbs on DC… A phenomenon called “filament notching” occurs which can cause the life of the bulb to be less than half that running the same bulb on AC. It gets even worse if the bulb is in a vibrating environment.
I didn’t know about “notching.” Found some concise documentation about it and similar filament phenomena from Toshiba. if anyone else is interested.
That explains why the lifespan of incandescent bulbs on a helicopter is so horrendous.
lots of interesting information there, thanks