Sylvania silverstar headlights worth it?

[Fenixgoon]

+1 for aiming the headlights. get them aimed and *then* see how bad your lights really are.

 

[Apex]

You know what, you're right, I'm completely sure that a bulb throwing light in places the reflector was never designed for will be just fine.

It is simply not optically possible for the beam pattern to remain the same with the combination of higher output as well as the uncoated tip. The lamp housings designed for H9 bulbs have different reflector designs. These aren't like the old lens-optic headlights that cars used to use, the uncoated tip on the H9 absolutely will fuck with the beam pattern. Basic rules of optics dictate this. It's not a matter of needing to try it to know that.

I don't need to drop a cinder block on my foot to know it will hurt because I have a basic grasp of gravity. Similarly, I know that putting an H9 bulb in an H11 housing will fuck up the beam pattern because I have a basic understanding of optics.

How much light do you think actually comes through the tip of the bulb? Not much at all because of the alignment of the filament. This is why the cap on the tip of the H11 varies in size from bulb to bulb (some extend down the barrel a ways, others sit right at the tip)... because it doesn't matter. It's merely blocking direct view of the filament.

If you don't believe me, give it a try. Real world experience trumps vague theory anyday.

Uh, no. The reason that 3200 lumen low beam HIDs don't blind people is because of incredibly tight optical design that limits the amount of light in the hot spot to roughly the same as that of traditional 1300-1400 lumen halogen bulbs. Laws governing beam pattern and maximum lumens in given areas of the pattern dictate this. Almost all of the additional lumens produced by HID lights is "thrown away" into useless areas of the beam pattern to avoid projecting it in places that will cause glare. Interestingly, it's precisely this "wasted" light in non-critical areas that makes drivers believe they are better even when the actual differences in projection distance and visual acuity are negligible.

Uh, yes. Apples to apples, our eyes don't perceive brightness linearly. There's loads of examples of this on the home theater front too. A doubling of output only yields about a 10% increase in perceived brightness. But yes, I agree that HID optics are made to control hotspotting.

A housing designed for a 1350 lumen bulb will put a much higher percentage of light into the beam's hot spot than a housing designed for a 2100 lumen bulb. Putting a 2100 lumen bulb in the 1350 lumen housing has a very good chance of causing excessive light in the beam's hot spot and being a legitimate problem for oncoming drivers.

To expound on the issue, I'll quote from Daniel Stern:


I'm sure that you think it's fine and that you've managed the swap without getting caught, but the simple fact is that it's physically impossible to put an H9 in an H11 housing and get an identical beam pattern. You may get lucky and not have a truly awful pattern, but it will never be even as good as the original pattern with the H11 bulb.

I say again, the OP needs to have his headlights aimed properly and proceed from there, not just shove any ol' high-lumen bulb into the socket.

ZV

Agreed, the H11 housing, being a low-beam headlamp, is made to minimize hotspotting as compared to high-beam applications.

However, from all of the H9/H11 swaps I've seen and tried, the beam pattern is nearly identical. You'd need pretty bad luck to manage to get a swap with a truly awful pattern, or even one marginally worse than the original H11. Can it happen? Of course. Does it happen often in this application? Rarely.

Daniel only sells through E-mail. Candlepower is a separate entity.

Daniel Stern's store:


Candlepower is indeed reliable, but it's not Daniel Stern's store.

ZV

You're absolutely right, not his store. My bad. He had suggested that store before, which is why I had thought he ran it.

 

[BassBomb]

when was the last time you changed your bulb? they dim as they age

 

[Zenmervolt]

How much light do you think actually comes through the tip of the bulb? Not much at all because of the alignment of the filament. This is why the cap on the tip of the H11 varies in size from bulb to bulb (some extend down the barrel a ways, others sit right at the tip)... because it doesn't matter. It's merely blocking direct view of the filament.

If you don't believe me, give it a try. Real world experience trumps vague theory anyday.

If it doesn't matter, why is it there? Of course it matters. It changes the pattern of emitted light and is certainly accounted for in reflector design.

The diagrams you link show how much light is emitted by each area of the filament, but they do not show how much light is being projected in any given direction. Their purpose is to illustrate the differences in shape and intensity of filaments and arcs (this is clear on the page on which the image is used, though you, for some reason, have stripped the image of its context) and to show that even the minor change in shape from filament to arc is enough to require different reflector design.

I'd love to try it. You go ahead and buy me the necessary light metering equipment and rent a garage to control ambient light and I'll gladly set up the experiment. Anything else though is just some schmuck throwing the wrong bulbs into his headlights and assuming that since it looks better to him it's legal or useful.

Uh, yes. Apples to apples, our eyes don't perceive brightness linearly. There's loads of examples of this on the home theater front too. A doubling of output only yields about a 10% increase in perceived brightness.

Good job arguing against something that I never said. :thumbsup:

But yes, I agree that HID optics are made to control hotspotting.

So you agree that you were wrong when you said that the increased lumen output wasn't an issue because HIDs don't blind people. Excellent. We might actually be making progress now.

Agreed, the H11 housing, being a low-beam headlamp, is made to minimize hotspotting as compared to high-beam applications.

However, from all of the H9/H11 swaps I've seen and tried, the beam pattern is nearly identical. You'd need pretty bad luck to manage to get a swap with a truly awful pattern, or even one marginally worse than the original H11. Can it happen? Of course. Does it happen often in this application? Rarely.

You didn't read what I wrote at all, did you.

A housing designed for a 1350 lumen bulb will put a much higher percentage of light into the beam's hot spot than a housing designed for a 2100 lumen bulb. Putting a 2100 lumen bulb in the 1350 lumen housing has a very good chance of causing excessive light in the beam's hot spot and being a legitimate problem for oncoming drivers.

There are very good chances that using the higher-power bulb in the reflector designed for the lower power bulb will result in excessive light in the hot spot even if the shape of the pattern is roughly similar. This excessive hot spot light is a risk to other drivers and is likely to exceed legal levels.

There are strict legal limits for how much light can be in any given area of a headlamp beam. Simply substituting a higher-power bulb in the same housing is likely to cause excessive light in portions of the beam and even though it looks better from behind the wheel, it's not.

For example, purely hypothetically, let's say that we have a housing designed for a 1350 lumen bulb and that there's a legal limit of 1,000 lumens in the hot spot of the beam. For legal wiggle room and to accommodate variance, the housing is likely to be designed to put 900 lumens into the hot spot. That's about 2/3 of the light's output.

Now, let's put a 2100 lumen bulb in that same housing, which is still sending 2/3 of light output into the hot spot. Now we have 1400 lumens in the hot spot. This is well in excess of the legal limit but from behind the wheel of the car it looks OK; the pattern shape is still similar. It's illegal and it increases glare to oncoming drivers significantly, but hey, the driver doesn't care because he thinks it looks fine. That's the problem with putting ridiculously high-lumen bulbs in housings designed for lower-lumen bulbs.

ZV

 

[Zenmervolt]

One other thing to remember about the perceived brightness of headlights is that they are effectively a point source, which changes the base for the log table fairly significantly. And when you're dealing with moving headlamps, driving conditions often create a situation in which the light source is effective both a point source and a brief flash. This makes it very different from the 5-degree swath in a moderately-dark room that is applicable to home theatre settings.

In fact, a point source briefly flashed has an exponent of 1, which means that its perceived intensity is linear with its actual intensity, and a point source even without flashing has an exponential value of 0.5 rather than the 0.33 used in evaluating home theatre setups. It's just not accurate to assume that the formulae for brightness perception of home theatres is sufficient for describing the perceived glare of headlights.

ZV

 

[chin311]

i like these

http://www.powerbulbs.com/product_detail.asp?prod=43&gclid=CM7gtL7f-qICFQG3sgodP0Qcig

 

[MrMatt]

+1 for aiming the headlights. get them aimed and *then* see how bad your lights really are.

why would they be 'askew' in the first place though? The car's never been in an accident

 

[MrMatt]

when was the last time you changed your bulb? they dim as they age

Never had to actually. They're at least 4 years old.

 

[jtvang125]

If your headlight housings are plastic try using those plastic polish to help remove any of the oxidation. I've seen some cars where it's so bad you can't even see the bulb reflectors inside anymore.

 

[Apex]

If it doesn't matter, why is it there? Of course it matters. It changes the pattern of emitted light and is certainly accounted for in reflector design.

It's there to block direct view of the filament from oncoming drivers, which I mentioned many many times before. The filament is the point source for the light and can very easily hinder vision for anyone looking directly into it. It's like the difference between looking at the light thrown by a flashlight, and looking directly into the bulb.

I'd love to try it. You go ahead and buy me the necessary light metering equipment and rent a garage to control ambient light and I'll gladly set up the experiment. Anything else though is just some schmuck throwing the wrong bulbs into his headlights and assuming that since it looks better to him it's legal or useful.

Again, I'll take real life over theory anyday, as would most people. I can understand you're lack of desire to try it for yourself without someone else funding your tests. However, the bottom line is your lack of real world experience here.

I can easily evaluate whether something throws more useful light for the driver. It's really not that hard, it just takes some time. Whether or not it's legal, I bet it's not legal, much like the SRT-4's stock exhaust, or hanging an airfreshener from your rearview mirror. I've never argued that it would follow the letter of the law.

Good job arguing against something that I never said. :thumbsup:

Since you forgot, I was replying to this:

Also worth noting is that 2100 lumens is considered high output for a high beam headlight. Using 2100 lumen bulbs in low-beam headlights is a recipe for creating massive amounts of glare for other drivers.
ZV

It's not the output difference of the bulbs that would cause massive amounts of glare. If the hot spots change in size/intensity/location substantially, that would be a possible cause for glare. A simple linear increase in brightness would not.

So you agree that you were wrong when you said that the increased lumen output wasn't an issue because HIDs don't blind people. Excellent. We might actually be making progress now.

I did not say I was wrong. I said that a marginal increase in brightness won't be the main cause in blinding people. Re-read it.

I understand your arguments, and frankly, really respect you for sticking to your guns, but let's try to keep things from wandering into the petty.

You didn't read what I wrote at all, did you.

There are very good chances that using the higher-power bulb in the reflector designed for the lower power bulb will result in excessive light in the hot spot even if the shape of the pattern is roughly similar. This excessive hot spot light is a risk to other drivers and is likely to exceed legal levels.

There are strict legal limits for how much light can be in any given area of a headlamp beam. Simply substituting a higher-power bulb in the same housing is likely to cause excessive light in portions of the beam and even though it looks better from behind the wheel, it's not.

For example, purely hypothetically, let's say that we have a housing designed for a 1350 lumen bulb and that there's a legal limit of 1,000 lumens in the hot spot of the beam. For legal wiggle room and to accommodate variance, the housing is likely to be designed to put 900 lumens into the hot spot. That's about 2/3 of the light's output.

Now, let's put a 2100 lumen bulb in that same housing, which is still sending 2/3 of light output into the hot spot. Now we have 1400 lumens in the hot spot. This is well in excess of the legal limit but from behind the wheel of the car it looks OK; the pattern shape is still similar. It's illegal and it increases glare to oncoming drivers significantly, but hey, the driver doesn't care because he thinks it looks fine. That's the problem with putting ridiculously high-lumen bulbs in housings designed for lower-lumen bulbs.

ZV

Much of this part of your argument I definitely agree with. You should see a similar pattern, with a reasonably linear bump in output. It should make it non-DOT compliant.

An increase in this example of 900 to 1400 lumens should appear to oncoming drivers as a 3-4% increase in perceived brightness.

 

[Zenmervolt]

An increase in this example of 900 to 1400 lumens should appear to oncoming drivers as a 3-4% increase in perceived brightness.

No. That figure only applies in the case of a 5-degree patch in a moderately-dimly lit room. As I showed in the link I provided, a point source flashed briefly has a linear relationship between actual brightness and perceived brightness, and even without flashing a point source like headlights has a much stronger relationship between perceived and actual brightness.

I say again, the relationships you're using are from entirely different setups.

Also, if that difference in lumens is really only 3-4% difference in perceived brightness as you claim, then it's not possible to notice any improvement in headlight output from the driver's seat. Either the difference is enough to give a big increase in a driver's ability to see, in which case it legitimately is the is the glare risk to other drivers. Or the increase is so small that it's not noticeable and can't cause glare, in which case there's not going to be any perceptible difference from behind the wheel. You can't have it both ways.

ZV

 

[Fenixgoon]

why would they be 'askew' in the first place though? The car's never been in an accident

things rattle around, tolerances might loosen over time. if you've ever taken the housings out to change the bulb, you probably didn't put it back in the exact same spot.

aiming the headlights is relatively simple and can't possibly hurt.

 

[Apex]

No. That figure only applies in the case of a 5-degree patch in a moderately-dimly lit room. As I showed in the link I provided, a point source flashed briefly has a linear relationship between actual brightness and perceived brightness, and even without flashing a point source like headlights has a much stronger relationship between perceived and actual brightness.

I say again, the relationships you're using are from entirely different setups.

Also, if that difference in lumens is really only 3-4% difference in perceived brightness as you claim, then it's not possible to notice any improvement in headlight output from the driver's seat. Either the difference is enough to give a big increase in a driver's ability to see, in which case it legitimately is the is the glare risk to other drivers. Or the increase is so small that it's not noticeable and can't cause glare, in which case there's not going to be any perceptible difference from behind the wheel. You can't have it both ways.

ZV

Sorry for the delay, was out of office today.

While there are criticisms of the SPL only holding with respect to relatively low luminance levels (ie. starlight), even assuming it holds, we're talking a 25-30% gain at most.

In terms of noticable improvement, I agree, the gain is relatively small. Worthwhile? Well, IMHO, a bit more so in H9/H11 applications than the 9005/9006 applications, which in turn seem much better than the H4 ones that I've seen.