[flash]

lol - yeah - i'm not much of a halogen fan, that's for sure - the tendency to lean toward red light drives me nuts - much the same with the blue light of projectors



the human eye sees yellow light best - that works best for headlights for me - it's not just about brightness - i know about all the arguments about yellow light, but i've also driven with them and know what the realities are - my eyes are particularly sensitive to glare, and am not very comfortable with the new lights - they make my eyes very tired much faster - i've done a lot of all night driving, and with a lot of different kinds of lights - contrast is much better in yellow light, and it's contrast that the human eye lacks the ability to see in the dark



if i could figure out how to legally change all of my lights to yellow, i would in a heartbeat

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[saxman]

the problem with yellow lights is that they significantly reduce the light output of the bulb. While they offer decent contrast of some objects, the fact that they generally work(obviously this doesn't relate to a sodium burning light) by just filtering out higher k wavelengths means you're just reducing light output. You get the contrast in value of objects because of the monochromatic light output, but this also causes some objects to simply not be visible.



In reality, the whole yellow headlights thing came as a result of the french thinking they'er better than everyone else. They were convinced that they had some sort of special fog there that's unique to France, and can only be cut through with yellow lights. For a while, it was only legal to have yellow lights there. They've since learned the error of their ways and have gone back to normal headlights.



The glare in adverse weather conditions that most people attribute to white lights and claim yellow is better for, is actually a result of poor optical design. Yellow lights offer less glare simply because they output less light. With proper optical design, this doesn't become an issue.





Was it you flash that I recall reading about having a high sensitivity to glare at night due to some accident way back when? If so, obviously everything does appropriately apply to your circumstances.





Interestingly, you mention the newer lights making your eyes tire faster, yet most people experience the exact opposite with high quality hid projectors(especially those using a soft or fresnled lens) due to less strain on the eye from poor light output. If, however, your experience is behind the wheel of something like an S2000, one of the audis, or something similar that has a very sharp cut off with a good amount of color, this may explain why... the harshness of going from really dark to really bright can cause those problems.

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[flash]

no, i had a flash fire go off in front of me, hardening the corneas a bit, making me more sensitive - i actually see very well in the dark though - however, there is actually a wide range of sensitivity to glare in people



the projectors i have been driving are in the denali, and in the bmw, as well as a few rentals of verying types - always glarey, without contrast, and harsh - i find myself wanting to turn them off entirely and seeing better with just the parking lights in town, but alas, the ticket would not be fun - at least with the dash lights off, it's a bit better



it's a whole rods and cones thing, and the human eyes sensitivity to different colors



there is a really good article here that dispells the myths about these new bulbs and blue light - blue is bad - brighter is not necessarily better



http://www.danielsternlighting.com/tech/bu...ue/bad/bad.html

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[flash]

here's another one that's pretty interesting:



http://www.danielsternlighting.com/tech/bu...superwhite.html

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[saxman]

the funny thing is, oem hid bulbs aren't blue... at 4300k, they're actually still slightly on the yellow side of white, and certainly much lower than the 5000k or so that sunlight is.



That article is exactly right... and doesn't apply at all to actual oem hid components. It pertains to blue halogen bulbs and such, not real hid bulbs.



There's also another article on that site dicussing the CRI output of the bulbs, but it doesn't focus on which design. For exactly, a D1S hid bulbs has a much higher CRI than a D2S bulb, and then there's the D4S which is another beast all together.

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[saxman]

[quote name='flash' date='Sep 4 2006, 03:30 PM']here's another one that's pretty interesting:



http://www.danielsternlighting.com/tech/bu...superwhite.html

[right][post="25840"]<{POST_SNAPBACK}>[/post][/right][/quote]

again... interesting, but completely irrelevant to hid's

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[flash]

the part that was relevant there was on the color temps and such, and how misleading that is



here is a very detailed study on glare - the conclusions were that HID lights produce more glare and more discomfort than standard halogens, and about the same as the blue halogens - it's a tough read, but very informative

final_report_20RPI_20glare_20spectrum.pdf Size: 678.7 KB  Downloads: 15

i've found a lot more to support what i am saying too - what you think is better is really not - there is a lot of physiology involved, and it is not a simple thing to immediately grasp - i only know this from 40 years of driving with all kinds of lights - i would have thought brighter is better, or whiter is better, or hotter is better, but it just isn't



anyway, have fun with the project - that's what it's all about anyway, right?

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[saxman]

download won't let me download it... when I try to download it redirects me to downloading an index.htm file









while hids may cause more glare, and such, what they really offer is much more usable light. When you have twice the lumens to work with, it can be applied in a much better manner. If you could get a halogen bulb to output the same amount of light as an hid bulb, it may work a lot better. In the mean time, halogens just don't offer that performance.



With a well designed hid projector, I can get about 150 degrees of beam width from my headlights, with more visibility at the extents of the beam than my halogen headlights offered directly ahead of me. With halogens, the light output from the bulb is so much less, that this width and intensity simply can not be offered. This width has saved my life on the road, allowing me to see things that I simply would not have seen with the stock lights(i.e. the deer on the side of the road that decided to play target practice with my car, that I was able to avoid by seeing it a good bit earlier than I would have otherwise).



If the same light output was available from a halogen bulb, but with higher cri and less glare, it probably would be a superior light, but that's just not available now.

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[flash]

that is a common misinterpretation - more is NOT necessarily better - it is all about projecting light that the rods can use - the 30 something page report spells this out very clearly - more of the wrong light means more "noise" - while you might get more of the light you want, you also get more of the light you don't



a good analogy is with sound - louder does not mean you can hear better - clarity is everything - i run into this all the time when i am mixing a show - it more often than not, better to pull something DOWN than to push something up, to provide more clarity



try this the next time you are at a concert: listen to the show - then put your hand over your ears - you will notice the vocals jump out - this is because the human ear is "tuned" to that - filter out the rest with your hands, and suddenly you "hear" better



it is the same with light - push the yellows and greens (what the human eye is "tuned" to), and reduce the blues and whites - you'll get a more "visible" light



another thing is perhaps the problem you experienced is not in the type of light you were using, but rather the lens - there are a lot of variations there that make some good and some bad - some of the best lights i ever had were standard incandescent beams - cibie made them - amazing projection - then i took a rock and broke them - i could not replace them

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[saxman]

when you only have so much light to play with, you're very limited with where it can be aimed. Take a mag light for example... you can focus it into a small beam that's bright, but you can't see anything outside of the small focus area, or you can focus it into a big spot that's dull, but you can't really see too much of anything.



With the hids, you get the wide spread, but also have the light output to fill that width.



I've played around with halogen projectors as well(in my closet picture, there are a good 4 pairs of them in there), and while they offer much better optics than the stock reflector based lights on my car, they still lack the width that an hid projector offers. This is really evident by putting an hid bulb into those projectors(well, a rebased one designed for that application)... you get big hot spots in the middle and very dim sidelighting... The halogen lights don't have as light to play with, so it gets focused where it's needed most... in the middle.





While I'll agree more isn't necessarily better, and having too bright is bad, what you have to take into account is that this allows you to put light in places where it wasn't there at all before. It's more of an issue of some is better than none. Anything is an improvement when the light isn't there to start with, even if it isn't ideal lighting.

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[flash]

well sure, having light where it was absent before is a better scenario - that's why we have fog and driving lights too - i finally got the delani set up better by changing the focus of the lights so the lower mounted fog lights are set to the outside, and the low beams are more centered and a touch higher - i am probably going to yank the projectors though, and go back to standard lights - lol - ironic, because the projectors are a fairly hefty "upgrade" on the standard yukon, though standard on the denali, and i am looking to remove them



i have done the same thing in focusing though on the porsche - now if i could just dim the headlights just a touch more, i'd be fairly happy (since i can't go yellow) - the stone guards helped in that regard a lot



something i forgot to mention (i must be getting old) - we do this on camera and on stage all the time - to add contrast and depth of field, witout creating hot spots and burns, thereby washing out the image, we add yellow light in a sort of "wash" - it tones down the glare of the blues and whites very nicely, and really makes things pop



very standard technique - check it out the next time you are at a show

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[saxman]

problem with fog lights is that they're meant for only adverse weather condition use, with the headlights turned off. They apply a lot of light directly in front of the vehicle, which really hurts your vision at distance. With a properly designed set up, you should never run the fogs and headlights at the same time.



With a driving light, you have the same issue with the width of the beam. Driving lights tend to be more of a pencil beam which may offer a lot of light directly in front of the car, but offers very poor lighting in the width of the beam.

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[flash]

lol - ok - now you're just playing with me



in fact, in most states it is illegal to have foglights on without the low beams on at the same time - here in california, it's definitely illegal, just as it is to run with the parking lights, but no headlights



in the porsche, we have both - one comes works with the low beams and one with the high beams - in the denali, for example, the fogs won't even work without the low beams being on



lol - in retrospect, i think all of this may have just been an exercise to see how much i could dig up to support my point - good show - it was fun



at any rate, i can always change the projector to a yellower light, or adda rheostat, so get on it and make this work - a lot of people will be happy you did

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[saxman]

you have to differentiate between what is legal and what is ideal for the driver.



Yes, it is illegal in california(and probably everywhere else in the US) to drive with just fog lights on. There's no denying that... however, driving with the headlights on pretty much defeats the purpose of using fogs.





Basically, the reason fogs are used in foul weather is that the headlights are mounted in such a way that you get a lot of glare off of whatever the substrate(rain, fog, etc) may be. Light goes out and bounces back in your face, making it difficult to see. A fog light is meant to be mounted lower on the body, and aimed in such a way that this doesn't occur. They don't light up as much at distance and a lot more in the foreground.



When running fog lights legally, you still have all the glare of the headlights, preventing you from being able to see well. Seems kinda silly to me to go through the hassle of adding a light designed to limit it's upward cast light so not to cause excess glare and to be visible in poor weather, and then be required to run with your headlights on that makes it all for nothing.

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[flash]

i don't know where you read that, but that is not what i have read anywhere - can you show me that? i've owned about 20 different sets of fog lights (mostly KC, Cibie, and Hella) over the last 4 decades and 40 cars, for all kinds of vehicles, including off-road, not even counting the ones that came with the cars, and none of them said that anywhere, in fact, quite the contrary



from everything i've read, and experienced, foglights are designed, not to penetrate fog, no light will do that, but instead they are designed to light up the peripheral areas (the sides of the road and the lines) - they are there to wash the area in a light that cuts glare, typically yellow in aftermarket, but often white in OEM - this helps provide depth of field, and give the driver a better sense of distance - they are designed to be used in conjunction with low beams, and not by themselves

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[Anchorman]

Everything I recall, and my personal experience, points in the direction of "fog on, low beams off". Try it next time you're in fog - the visibility improvement is considerable. For that reason, I'm glad that the 968 fogs will operate without the headlights being on.

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[968rz]

I would tend to favor Flash on this one. In all my experience in the automotive biz, fogs were more to BE seen as opposed to seeing. The reason they are mounted so low is to try and get under the fog so they can TRY to light the road.

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[Anchorman]

The rear "fog" light(s) on many European cars are there to help you be seen. The fronts are there to help you see - and you describe that accurately. By being low, they are not only (possibly) under the fog, but the light is not reflected back (nearly as much) into the driver's eyes. Next time you're in fog, turn on the fogs and then turn off the headlights - once your eyes adjust, the difference is obvious.

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[flash]

i've done the "fog light only" thing years ago, when i did a lot of things that got me tickets - while the periphery was enhanced, overall vision was not - this was largely due to placement and aiming - what did work well, was when i was running yellow headlamps



so, in theory, with the proper lumens and aiming, if they were available, fog lights would work well alone, which also coincidentally agrees with my yellow light comments - however, given the laws here, which are very specific when it comes to lighting design (i think fed 18 is the code), fog lights are not allowed to be sold if designed to be used alone on a street vehicle



every package i have ever seen has had the use printed right on it - the only ones i have ever seen, that could be used alone, clearly said "not for use on a highway"



so, perhaps it's semantics, but since you can't install them on your car, it's a rather moot point

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[saxman]

flash... you've pretty much hit the nail on the head.



With proper aiming, lumens, and most importantly proper optical design(for a good fog, you basically want a design similar to a projector that gives a really wide beam, and has a upper and lower cut off, that gives a very wide beam horizontally but very narrow vertically), fogs alone are ideal. Unfortunately, very few lights fit that description, at least out of the box, and there are all those legal problems preventing safe foul weather driving.



But hey, the past page or so has been basically about ideal set ups, so might as well take all the angles into consideration.







Anyway, since we've covered that hids have their disadvantages over halogens, but the halogens just lose out in the amount of usable light available, that proper fogs are great except that some government pencil pusher thinks it's best to keep the headlights on in the fog, and that 993 headlights seem to be the prefered appearance if they can be kept somewhat stock looking, but completely functional when integrated well into the fenders at an angle, lets carry on.





Does anyone have any pictures of how the 993 lights fit into the stock fenders when laying back like the stock lights? The lights fitting into the fender is a bigger issue to me than dealing with alligning the projector inside the headlight, that's easy, albeit tedious, stuff.

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