Headlight throw

[lwil1962]

Hi fellows. What would you regard as the normal distance of light throw on low beam ?

 

[herosemblem]

Are you asking for normal DESIRED/idealt hrow on low, or are you just seeking actual distances in the real world? I assume the latter.

 

[dave_b]

This is a very interesting question. I just installed the ECE version headlights on my vehicle. I dont really know what I expected in terms of distance, but I was they seem just a tad shorter than I would have liked after being aimed at the dealership. However, with +50 bulbs and relays, the amount of light under the cutoff is amazing and over all they are much nicer to drive behind. Same goes for my mom's Audi A4 with HID that I recently was able to drive. I was a bit suprised at the (percieved lack of) throw, but what they do illuminate is excellent and again, nice to drive behind. (subjective observations)

 

[lwil1962]

Are you asking for normal DESIRED/idealt hrow on low, or are you just seeking actual distances in the real world? I assume the latter.

Actual distances in real world actually. Mine seem to light up the road about 140 feet ahead.

 

[270winchester]

depends on the car I suppose. There are lighting laws in place but interpretation of said regulations can result in different beam reach, and depending on if the car is a passenger car, a cross over, an SUV, etc you will see vastly different lighting patterns.

 

[lwil1962]

depends on the car I suppose. There are lighting laws in place but interpretation of said regulations can result in different beam reach, and depending on if the car is a passenger car, a cross over, an SUV, etc you will see vastly different lighting patterns.

I should add that i drive an suv and the lamps are 32 inches off the ground. 140 does seem a bit inadequate even though i have ecodes.

 

[-Virgil-]

Seeing distance is quite variable because of the large range of legally permitted performance and of headlamp mounting height. Low beam seeing distance in the US ranges from roughly 200 to 300 feet. Keep in mind that seeing distance down the road is only one of several important headlamp performance parameters. For many years US headlamps tended to produce a "hot spot" beam pattern very heavily weighted in favor of seeing distance. Now we have a much wider variety of beam patterns on the road. Some of them emphasize seeing distance, some emphasize glare control, some emphasize width, some emphasize foreground light, etc. Keep in mind that vertical aim is the most important factor in headlamp safety performance, and take the time and trouble (and pay the money) to get them aimed correctly. And remember, if you are using UN ("European") headlamps in North America, aim them to the US "VOL" specification, not the lower European specification which gives much shorter seeing distance.

 

[hokiefyd]

Hi fellows. What would you regard as the normal distance of light throw on low beam ?

As others have said, it really depends on a wide variety of factors.

One of my cars has VOR lamps at 33" from the ground. The right side of the pattern is adjusted to be level with the horizon ("horizon" meaning the horizontal plane level with the center of the bulb as I understand it), and the left side of the pattern steps down left of center. So my seeing distance on the right side of the pattern could be described as "infinite", depending on the intensity of the bulb. There is certainly a cutoff line visible on the road from the left side of the pattern, but I'd say that it's WELL out in front of me...a few hundred feet anyway. I never have measured it precisely.

My other car has VOL lamps at nearly 36" from the ground, with the left side of the cutoff aimed to be 3" below the horizon at 25' away. Therefore, doing some simple math, we know the left side of the cutoff line will show on the road at or around 300' from the vehicle. The right side of the cutoff is actually near or above the horizon, as this particular lamp has a fairly pronounced step that obviously grows with distance from the vehicle. So like my other vehicle, the seeing distance on the right side of this one is limited only by bulb intensity.

You were asking about "light throw", which I would define as "visible light on the ground". Depending on the glare control of your housings, you may or may not be able to see reflectors at some distance beyond a visible cutoff, or beyond your visible light throw. My vehicle with VOL lamps uses projector low beams with fairly good glare control on the road, and reflectors on the road generally aren't all that visible beyond the cutoff. Reflections above the road stand out very well, because there is a controlled area of glare above the cutoff, but at some measure above the cutoff so that it's not a bother to most oncoming drivers. My vehicle with VOR lamps uses HB2 free-form reflector housings, and road reflectors beyond the cutoff are generally more visible in this car than in my other one.

 

[lwil1962]

As others have said, it really depends on a wide variety of factors.

One of my cars has VOR lamps at 33" from the ground. The right side of the pattern is adjusted to be level with the horizon ("horizon" meaning the horizontal plane level with the center of the bulb as I understand it), and the left side of the pattern steps down left of center. So my seeing distance on the right side of the pattern could be described as "infinite", depending on the intensity of the bulb. There is certainly a cutoff line visible on the road from the left side of the pattern, but I'd say that it's WELL out in front of me...a few hundred feet anyway. I never have measured it precisely.

My other car has VOL lamps at nearly 36" from the ground, with the left side of the cutoff aimed to be 3" below the horizon at 25' away. Therefore, doing some simple math, we know the left side of the cutoff line will show on the road at or around 300' from the vehicle. The right side of the cutoff is actually near or above the horizon, as this particular lamp has a fairly pronounced step that obviously grows with distance from the vehicle. So like my other vehicle, the seeing distance on the right side of this one is limited only by bulb intensity.

You were asking about "light throw", which I would define as "visible light on the ground". Depending on the glare control of your housings, you may or may not be able to see reflectors at some distance beyond a visible cutoff, or beyond your visible light throw. My vehicle with VOL lamps uses projector low beams with fairly good glare control on the road, and reflectors on the road generally aren't all that visible beyond the cutoff. Reflections above the road stand out very well, because there is a controlled area of glare above the cutoff, but at some measure above the cutoff so that it's not a bother to most oncoming drivers. My vehicle with VOR lamps uses HB2 free-form reflector housings, and road reflectors beyond the cutoff are generally more visible in this car than in my other one.

Interesting that you said that, because the reason i wrote this was because, the night before, i was driving down the road on low beam and i didnt see a truck stopped in the middle fhe road, with no lights on until i was about 30 feet or so behind it, when my headlight caught the reflector. Which is why i wondered if the throw was normal. i had put new bulbs in the a couple weeks ago, and it seemed the the seeing distance had decreased a bit. Last night i reaimed them and it seems a bit better so far.

 

[lwil1962]

Seeing distance is quite variable because of the large range of legally permitted performance and of headlamp mounting height. Low beam seeing distance in the US ranges from roughly 200 to 300 feet. Keep in mind that seeing distance down the road is only one of several important headlamp performance parameters. For many years US headlamps tended to produce a "hot spot" beam pattern very heavily weighted in favor of seeing distance. Now we have a much wider variety of beam patterns on the road. Some of them emphasize seeing distance, some emphasize glare control, some emphasize width, some emphasize foreground light, etc. Keep in mind that vertical aim is the most important factor in headlamp safety performance, and take the time and trouble (and pay the money) to get them aimed correctly. And remember, if you are using UN ("European") headlamps in North America, aim them to the US "VOL" specification, not the lower European specification which gives much shorter seeing distance.

Thanks for the info Scheinwerfermann. I had changed the bulb a few weeks back so i realised that i wasnt seeing as far as before on low beam,

 

[hokiefyd]

What is the vehicle in question?

 

[lwil1962]

What is the vehicle in question?

a nissan patrol like this one.