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Old 01-19-2003, 01:34 PM
artpb's Avatar
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H4 Dilema

I am an engineer which makes selecting simple things very difficult for me. As in an H4 bulb. Now I am familiar with the excellent rundown on lighting at Dan Sterns Website. I agree you cannot put 55w into a passive device and get more out. What I do know is that efficiency of a conversion process can be increased. As in the case of electricity to light. That is less loss to heat. So here we go.

Read all abt it all over the net. Osram, Philips, Sylvania etc. claiming 30%-40%-50% more more light. Until recently hard to get. Only available in Europe or via a few select Websites. Drives me nuts.

Let's take the case of the Philips VisionPlus. Is this 50% percent more light the result of a more efficient design or is it more marketing stuff. Do they really produce more lumens or candlepower or whatever? Or is it redirected across the field of vision and measured by the marketing guys.

These new lights are supposed to be Homologated. AHA thats the secret. What is Homologated anyway? What's a guy to do. Why don't people who use these big words ever explain them?

I really would like to understand all this so I can order my bulbs and go watch the football game.


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Old 01-19-2003, 07:59 PM
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Homologated AHA? Never heard of it, but the words would be defined as: officially approved by the AHA . The anagram AHA means American Heart Association in my field; maybe it means American Halogen Assoc. to lighting industry marketing dept.
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Old 01-19-2003, 08:41 PM
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ArtPB: As an engineer, you are certainly comfortable with some electrical concepts. Volts X amps=watts;A watt is a watt An output of 50 watts is what it is. You can not have an output of 60 or 70 watts out of a 50watts light bulb. You can play with the color of light and other variables but the output will always be 50 watts.
The only way to increase the output is to play with voltage and/or amps.
Saying a 50watts light has 30 or 40% more light than an other light is like saying ''my pound is heavier than yours''
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Old 01-19-2003, 09:28 PM
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Light output is measured in lumens, or candlepower. Watts is an electrical unit. The fluorescent household lights put out a lot more light per watt, but this technology isn't in use in H4 bulbs.

My impression of the "halogen" technology was that a halogen bulb was good for maybe 10% or so more light per watt. I wonder what technology gives 50% more light output.

I'm assuming these new H4's still use a tungsten filament... can a different filament design or some special gas inside the lamp make a 50% difference?
I don't know...
Bob Roe
Lehigh Valley PA USA
1973 Olds 88, 1972 MB 280SE, 1978 Datsun 280Z, 1971 Ford T-Bird, 1972 Olds 88, 1983 Nissan Sentra, 1985 Sentra, 1973 230.6, 1990 Acura Integra, 1991 Volvo 940GLE wagon, 1983 300SD, 1984 300SD, 1995 Subaru Legacy L wagon, 2002 Mountaineer, 1991 300TE wagon, 2008 Murano, 2007 R320CDI 4Matic 52K, some Hyundai, 2008 BMW 535xi wagon, all gone... currently
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Old 01-19-2003, 10:19 PM
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brand X bulb CAN be brighter than brand Y

robert, you are correct sir: lumens is the measurement of output.

thus, it is possible that brand X can output more measurable light than brand Y at the same rated wattage bulb.

true HID lights ouutput more light (or at least in what they advertise as being in a more useable spectrum) at rated watts that are close to 55W as is utilized in most "conventional" systems.

as for being homologated, as used in racing jargon: auto manufactures are required to produce a certain number of cars for sale as retail units for the cars to be considered true production models in order to be "homologated" or approved by the sanctioning body. this is as opposed to one-offs or specials.
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Old 01-20-2003, 06:21 AM
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Location: Epsom Downs, England
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H4 Dilema

The light output of the latest generation lamps (zenon) is claimed to be 30% higher than Halogen.

The problem is that the eye's perception of brightness is logarithmic, so that 30% more amounts to "not much".

Having seen them I think that's about right.

To get a really noticable improvement you have to go to HID, but you're talking several hundred pounds for the conversion because of all the control electronics. These prices are sure to come down, but not for a few years........

So I guess the answer is: if you need a new bulb, go for a zenon one, because they are a bit brighter and don't cost much more, but the improvement is not worth changing a working bulb for.
Paul Gibbons
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Old 01-20-2003, 05:19 PM
Ali Al-Chalabi's Avatar
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Location: Knoxville, TN
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Different types of bulbs give off different amounts of light.

A standard 55w H4 bulb produces 1000 lumens of light. A 55w H7 bulb like that used in the C class produces 1335 lumens, so there is variation in Halogen bulbs depending on the type of bulb.

Also, a standard 35w xenon bulb produces 3200 lumens of light.

The xenon light produces 320% more light than a H4 bulb!
Ali Al-Chalabi

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Old 01-20-2003, 08:24 PM
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Location: So Cal
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I bought H7 Phillip Vision Plus for my wife 00 E430 after reading Daniel Stern article about lighting. He said "For those who want the best possible performance from their headlamps and are more concerned with their ability to see rather than the appearance of their headlamps, the major bulb companies offer optimized bulbs WITHOUT the light-stealing blue coloration. Sylvania Xtravision (in the pink-and-black package), Osram Super and SilverStar(outside North America); Philips High Visibility (North America), Premium and Vision Plus (outside North America); Narva RangePower are the ones to look for."

I can say that the Phillip Vision Plus gives more light on the road compares with standard Hella H7 which is OE for that car, the color is somewhat whiter too. I think it worths $40 for a pair of H7. A pair of H4 Vision Plus is $28, shipping is included.
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Old 01-21-2003, 11:48 AM
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Location: Newcastle upon Tyne, UK
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An incandescent light bulb like a household bulb has an efficiency of about 5%. This means that 95% of the energy is converted to heat.

The design of a light bulb can be played around with to improve light output, but the trade off is reduced lifespan.

Generally speaking, you increase the light efficiency by running the filament at a higher temperature where, although the heat output increases, the light output increases more. But the problem is that the filament burns out faster. That's why halogens are more efficient because the halogen gas reacts less with the hot tungsten in the filament than the residual gas in an ordinary light bulb, so the temperature can be pushed up with an acceptable lifespan. Xenon reacts even less, so these are more efficient again.

Cheers, Neil
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