A buyer just sent a short video clip driving with the China made LEDs.
Light up the night! Now offering LED headlights for 356’s, 912’s and ’65-’88 911’s. Click here for information.
Summary: Why H1’s (and H4’s) are Great Driving Lights
If you drive at 55MPH at night you are probably OK with just about any decent headlight. But if you occasionally exceed that, you need to be careful that you don’t out-drive your headlights. And H1’s, a 50 year old technology, do a great job of lighting up the road.
H1’s have a unique feature – the ability to adjust low and high beams separately. With two bulbs and two reflectors you have great flexibility in setting up your lighting to match the way that you drive.
H1’s use asymmetric lenses which enables them to distribute the light precisely. Low beam light is directed far down the road in your lane, but on the side of approaching traffic it has a much small pattern in order to keep the light out of the eyes of on-coming drivers. The high beam light covers things much more broadly.
The ability to adjust their low and high beams separately enables you to set the low beams conservatively while aggressively aiming the high beams far down the road. The high speed Autobahn type driving in Germany made it imperative to develop headlamp technology. I suspect that’s one of the main reasons that lighting technology was moving forward in Europe while stagnating with DOT imposed sealed beams in the U.S. You don’t need great lighting at 55MPH, but you sure do at higher speeds.
A Little bit of Technical Information
If you’re interested in the technology behind the great lighting provided by H1’s, please read on.
Some of the following is from, a publication by Bosch titled “Bosch Automotive Electrics and Automotive Electronics”. As a lighting geek, I find some of the information on lighting to be very interesting. For example, I have to admit I have never given much thought to what “asymmetric” meant when describing an asymmetric lens, such as those used on the early Euro headlights, H1’s and H4’s. An asymmetric lens is a clever device using optics that distribute the light unevenly, in this case with low beams.
and one of high beam light distribution:
As you can see, the low beam light is directed far down the road in your lane, but on the side of approaching traffic it has a much small pattern in order to keep the light out of the eyes of on-coming drivers. I surmise that that is what the prism (the same Fresnel lens technology used in lighthouses around the world) on the driver’s side of the lens does. The high beam light covers things much more broadly.
After reading the article I got out an H1 and tried to get an idea of how it manages the light. There is an interesting graphic in the article of how an H4 broadcasts light (couldn’t find one for H1’s, but I think they’re somewhat comparable). Here it is:
Here’s the legend:
#1 – Low beam filament
#2 – Shield
#3 – High beam filament
And a picture of a LHD H4 lens with the prism for the low beam circled:
The prism is on the side of the driver as that’s the side of on-coming traffic. As you can see, all of the light bounces off of the reflector (which is why you need the reflectors to be in great condition). The low beam projects off of the reflector at a downward angle. While the graphic and picture are of an H4, an H1 works pretty much the same. When you look at an H4 or H1 lens you can see what happens. The upper rays of the low beam are broadcast unimpeded while the lower rays are “bent” downward by the prism, keeping them out of approaching drivers eyes. The high beam projects off of the lower part of the reflector (of course the H1 has it’s own, separate high beam reflector) and is broadcast outward, underneath and unimpeded by the prism.
This really reinforces my high opinion of H1’s. The ability to adjust their low and high beams separately enables you to set the low beams conservatively while aggressively aiming the high beams far down the road. I’m sure these were born out of a need for adequate illumination for high speed Autobahn type driving. Not a good idea then – or now – to out-drive your headlights. I suspect that’s one of the main reasons that lighting technology was moving forward in Europe while stagnating with DOT imposed sealed beams in the U.S. You don’t need great lighting at 55MPH.
© 2015 ~ Audette Collection ~ Bend, Oregon
Concours Restoration of SWB Headlights & Turn Signals and H1’s ~ Email
Reproduction SWB Euro headlights are currently being offered, but they are, umm, flimsy and cheaply made. Seems like a shame to put cheap repro parts on a car so well built. I’m in the process of restoring four sets using original reflectors and buckets. A bit more expensive than the cheaper repro’s, but more solid and higher quality. Stay tuned.
I’ve just relaunched the Audette Collection Newsletter (no catchy title), a periodic mailing designed to provide you with information about SWB lighting: history, technical information, what is correct and what is incorrect, where to get original and quality reproduction parts and restoration information. I also provide information to list subscribers about new items that I have available for sale before I announce them elsewhere. Sign up below:
Audette Collection Newsletter
If your H1’s need some love but your reflectors are in good shape, there’s now a more economical and quicker way to take them to a concours level – H1 Refurbishment. And without the time and expense of replating the reflectors turnaround is quicker and the cost is much lower- Click here for details.
I have received many requests to restore original SWB headlights, both U.S. and Euro. I’ve decided to go ahead and offer that as a service. I figure that after working with H1’s for several years that I’m qualified at this point to work on most headlights! Information here.
I’m always interested in buying H1, H4 and SWB turn signal full assemblies in bits. Please let me know if you have anything available.
Welcome to my modest website. As you may have read I really enjoy working with early Porsche lights. As an enthusiast I initially was attracted to the versatility and brightness of H1’s on my longhoods and, as they are no longer available, over time I learned how to restore them. I have recently expanded my restoration services to include SWB turn signals and H4’s. Please feel free to ask questions or comment here at any time.