7" sealed beams

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Originally Posted By: Cubey
One other question... what's better? Reflector or projector?

Examples: http://www.hidny.com/index.php?main_page=product_info&cPath=146&products_id=392


Halogen projectors are horrible. Consider reflectivity losses in your optics. A typical chromed or aluminized reflector of proper size, will reflect about 70% of the light (yes, ultra high reflectivity coatings are used on expensive telescopes, but not headlights)

Consider bouncing that light of a smaller reflector, more loss. That's why a headlight bulb will perform better with a bigger reflector. More light reflected!

Now, consider doing this twice, and forcing it through a lens too. Losses can be as great at 80%! (my Jaguar X-Type's, halogen projectors perform this poorly!)

The best is always a large circular reflector, with a centrally located, compact light source. Anything else is worse.
 
Originally Posted By: eljefino
"City lights" are for euro posers. You have "parking lights" for that.
laugh.gif

If you have seen how visible a "parking light" which uses an entire 7 inch reflector is for the same input power you might change your mind. The front parking light on my BMW bike is a "city light" in an H4 lamp. Lights the whole thing, not jsut a little dot.
 
just fyi I remember that Hella make a standard Euro 7" w/H-4 and a discontinued 7" h-4 that matches US beam patterns - generally considered poor but may still be sold. Cibie made a bobi headlight, same concept, same inferior beam pattern, also discontinued many years back, produced to meet old time US standards that went away.
 
Originally Posted By: bmwjohn
just fyi I remember that Hella make a standard Euro 7" w/H-4 and a discontinued 7" h-4 that matches US beam patterns - generally considered poor but may still be sold. Cibie made a bobi headlight, same concept, same inferior beam pattern, also discontinued many years back, produced to meet old time US standards that went away.


yeah but why would anyone want those? THe real euro patterns that have a sharp cutoff and raised side ilumination is desirable. Less glare, more efficiency, etc.
 
Originally Posted By: JHZR2
Originally Posted By: bmwjohn
just fyi I remember that Hella make a standard Euro 7" w/H-4 and a discontinued 7" h-4 that matches US beam patterns - generally considered poor but may still be sold. Cibie made a bobi headlight, same concept, same inferior beam pattern, also discontinued many years back, produced to meet old time US standards that went away.


yeah but why would anyone want those? THe real euro patterns that have a sharp cutoff and raised side ilumination is desirable. Less glare, more efficiency, etc.
One of them was called the "Z Beam" as I recall.
 
nooooo, the Cibie z beam was a great light, although it did have a slightly modified beam on the right side. The ones I referenced had light patterns very similar to traditional US 7", meaning not good, and, IIRC, a bubble between the H4 and the reflector, which made it sort of a sealed beam with a replaceable bulb. Point of mentioning it was to remind folks that these lights still pop up on e-bay, etc. and would profoundly disappoint anyone expecting a Euro spec headlight.
 
Originally Posted By: bmwjohn
nooooo, the Cibie z beam was a great light, although it did have a slightly modified beam on the right side. The ones I referenced had light patterns very similar to traditional US 7", meaning not good, and, IIRC, a bubble between the H4 and the reflector, which made it sort of a sealed beam with a replaceable bulb. Point of mentioning it was to remind folks that these lights still pop up on e-bay, etc. and would profoundly disappoint anyone expecting a Euro spec headlight.


The whole idea behind the BOBI was to offer a DOT legal "sealed beam" lamp with a replaceable bulb. I ran a couple of sets Z-Beams in the '80s and '90s and the were great lamps the RH cut-off was just a bit more severe than the E-Codes.
 
Originally Posted By: bmwjohn
nooooo, the Cibie z beam was a great light, although it did have a slightly modified beam on the right side. The ones I referenced had light patterns very similar to traditional US 7", meaning not good, and, IIRC, a bubble between the H4 and the reflector, which made it sort of a sealed beam with a replaceable bulb. Point of mentioning it was to remind folks that these lights still pop up on e-bay, etc. and would profoundly disappoint anyone expecting a Euro spec headlight.
Kept the reflector from degrading. though.
 
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