Subaru Crosstrek and XV Forums banner
21 - 40 of 59 Posts

Registered
2020 Premium 6MT
Joined
1,471 Posts
For my Impreza I went with the sport version SS3's, they are way better than the OEM. Part of the reason was the cost too. While these aren't cheap, the others are super pricey. I have the Impreza sport so instead of fog lights it had DRL's in that spot so I had to rewire. My understanding is the Crosstrek it's just plug and play.

The fitment of the assembly should be the same for the most part:

Diode Dynamic Fog Light Install 2019 Impreza Sport

I've always been interested in how the eyes work (my biology background) and looked for the science behind selection of yellow for fog. In the process of trying to justify my use / like of yellow for fog lights based on science, rather than what I see on sites that sell fog lights. I could not find any. Did find one good paper with some interesting info. that suggested there may be a slight but non statistical advantage but for the life of me I can't find where I saved it. I found some others.

If anyone has good reference info that is more current than what I have, now that LED lamps are more prevalent, I would be very interested in seeing it.

Here are some clips of articles I've saved from science forums.

Most of the things I see today are not so much that yellow penetrates fog but the colour is easier on the eyes for the driver and on coming traffic. Not so much the yellow, but being away from the blue end of the spectrum, which is why white is okay too, if they are white with no blue.



There is no good reason why fog lights are yellow. Here is an excellent explanation provided by Professor Craig Bohren of Penn State University:
"First I'll give you the wrong explanation, which you can find here and there. It goes something like this. As everyone knows, scattering (by anything!) is always greater at the short wavelength end of the visible spectrum than at the longwave length end. Lord Rayleigh showed this, didn't he? Thus to obtain the greatest penetration of light through fog, you should use the longest wavelength possible. Red is obviously unsuitable because it is used for stop lights. So you compromise and use yellow instead. This explanation is flawed for more than one reason.

Fog droplets are, on average, smaller than cloud droplets, but they still are huge compared with the wavelengths of visible light. Thus scattering of such light by fog is essentially wavelength independent. Unfortunately, many people learn (without caveats) Rayleigh's scattering law and then assume that it applies to everything. They did not learn that this law is limited to scatterers small compared with the wavelength and at wavelengths far from strong absorption.

The second flaw is that in order to get yellow light in the first place you need a filter. Note that yellow fog lights were in use when the only available headlights were incandescent lamps. If you place a filter over a white headlight, you get less transmitted light, and there goes your increased penetration down the drain. There are two possible explanations for yellow fog lights. One is that the first designers of such lights were mislead because they did not understand the limitations of Rayleigh's scattering law and did not know the size distribution of fog droplets. The other explanation is that someone deemed it desirable to make fog lights yellow as a way of signalling to other drivers that visibility is poor and thus caution is in order.


the reasoning behind the selection of yellow as a fog light color had nothing to do with physics. I've heard two reasons cited as the rationale behind the use of yellow fog lamps: (1) yellow lamps suffer less backscatter into the eyes of the car's driver than blue or green, allowing them to see better in the fog; (2) yellow lamps are more readily seen by an oncoming driver, so that a car with fog lights on will be seen more readily than white lights would be. The first point is true for light scattered off very tiny aerosol particles in fog -- blue light is scattered out of the path from the sun to the viewer of a sunset, leaving white light minus blue to reach the observer... so he/ she sees yellow/red -- but is pretty irrelevant for the kind of yellow lights used for fog lamps. Those lamps were generally made by putting yellow filters over a hot tungsten filament incandescent lamp, so that a lot of light is lost in trying to make the yellow light -- reducing the brightness available for the driver to see, which is not such a good idea. Using a halogen gas fill increases the brightness of the bulb, but the same general principle of reduced brightness still holds. Additionally, the size of water drops in fog is generally not appropriate for producing the kind of scattering I mentioned above -- if so, headlights would appear very red to oncoming traffic, which they don't. The second point, that the yellow color is more visible to oncoming traffic is also true, but irrelevant as well. The point of fog lights is to allow the car's driver to see better, not to be seen better -- if you wanted to be seen better, a flashing strobe would be more effective, but you don't see much of those in the fog light business. Most likely, the real reason that people have used fog lamps that are yellow is that they look so cool.

<<


This article is provided as a public service by the Geophysical Institute, University of Alaska Fairbanks, in cooperation with the UAF research community. Larry Gedney is a seismologist at the Institute. I was asked the other day why fog lights were yellow. When I couldn't come up with an answer, I started asking around and discovered, to my surprise, that apparently nobody else could either. Skiers, shooters and other outdoor types have long known that yellow goggles or glasses enhance outdoor vision. This is because the yellow lenses filter out the blue part of the spectrum and increase the contrast of a scene. But does the same thing hold the other way around? With the goggles, we are filtering reflected light entering our eyes, but is it possible to illuminate something with yellow light and achieve similar results? The answer, apparently, is no (which is likely to raise strong objections from people who have been using yellow fog lights for years). For expert advice, I contacted the Cold Regions Research and Engineering Laboratory (CRREL) on Fort Wainwright. Captain John Craig of that group then arranged to have a computer search made on the subject of light penetration in fog and mist from CRREL's headquarters in Hanover, New Hampshire. As a result, I obtained a list of over 200 references and abstracts of articles published by researchers all over the world. Not a single one asserted that yellow light has superior penetrating qualities, but several specifically stated that it did not. To quote from one Russian article, for example: "Investigations and practices of automobile traffic do not confirm any substantial advantages of yellow light over white light. The advantages ascribed to it may take place only in very thin fog or may be subjectively received by some drivers owing to their individual peculiarities of vision. Therefore, it does not make any sense to switch over headlights to yellow light, although the use of yellow light in special fog lights does not raise any objections." End of quote. The phrasing is quaint, but the meaning is clear. I had long thought that the yellow sodium-vapor street lamps that are becoming common were used specifically because they cut through fog better. I found out that there actually is a specific reason for their use, but that it is because they operate on only about half the power of conventional lamps. So, unless you just happen to like yellow, save your money and forget about so-called "fog-lights." They don't exist.

<<
Thanks Peaty! So if the Sport version is considerably brighter than the stock, the Pro or Max may get the attention of a police officer or two - not something I really want.

Did you get the amber backlight? What exactly does this do and do you think there is any value in it?
 

Registered
2015 XV Crosstrek Premium CVT, 2019 Impreza Sport MT, 2001 Forester S 4EAT, 2013 Outback Premium CVT
Joined
256 Posts
When I got mine, the backlight was not an option. I think it's just for looks though, kind of like angel eyes you see on some cars.

And I agree, that while being a lot brighter might be really good off road, on the street it might bring some unwanted attention. The beam pattern is excellent, I put yellow ones in my kids truck and they really looked nice!
 

Registered
2022 Canadian Sport trim (6MT // 2.0 )
Joined
1,003 Posts
Allright, some clarification of amber/yellow vs. white. The actual answer stems from the properties of the eye. Reddish colours tend to focus more on the retina, whereas blue-ish light is a little bit off focus, which reduces our perception of sharpness. Secondly, on our retina, only 10% of cones (little light sensors) are sensitive to blue colour. As a result, our "blue colour resolution" is much smaller than for yellow, or red. To make it even worse, blue cones are mostly distributed away from the foeva (centre of the eye) - further reducing our vision sharpness right where we try to look. In simple terms: with a blue-ish light, we have much less detailed of a vision, especially at the centre, less contrast, and more susceptibility to glare (blue cones are the most sensitive out of all cones).

Interestingly, the common (but false) theory blames the atmosphere. Light of different colours is indeed scattered differently when going through a hazy medium. The sky is blue because the blue colours - straight from the sun - get dispersed AF, deviated by gas molecules. Yellow/red light mostly zaps in a straight line - so the sun is yellow(ish) while the sky is blue. However, that effect (Raylight scattering) is only present for really small molecules. Water droplets in fog are much larger (few um), and thus light propagates fairly simillarly through it (subject to Mie scattering, but that has much much less of an impact than our eyes do)

Yellow light vs white light in fog
(PDF) Light Transmission in Fog: The Influence of Wavelength on the Extinction Coefficient
Cones
Blue-Blindness in the Normal Fovea*
 

Registered
Joined
480 Posts
For my Impreza I went with the sport version SS3's, they are way better than the OEM. Part of the reason was the cost too. While these aren't cheap, the others are super pricey. I have the Impreza sport so instead of fog lights it had DRL's in that spot so I had to rewire. My understanding is the Crosstrek it's just plug and play.

The fitment of the assembly should be the same for the most part:

Diode Dynamic Fog Light Install 2019 Impreza Sport

I've always been interested in how the eyes work (my biology background) and looked for the science behind selection of yellow for fog. In the process of trying to justify my use / like of yellow for fog lights based on science, rather than what I see on sites that sell fog lights. I could not find any. Did find one good paper with some interesting info. that suggested there may be a slight but non statistical advantage but for the life of me I can't find where I saved it. I found some others.

If anyone has good reference info that is more current than what I have, now that LED lamps are more prevalent, I would be very interested in seeing it.

Here are some clips of articles I've saved from science forums.

Most of the things I see today are not so much that yellow penetrates fog but the colour is easier on the eyes for the driver and on coming traffic. Not so much the yellow, but being away from the blue end of the spectrum, which is why white is okay too, if they are white with no blue.



There is no good reason why fog lights are yellow. Here is an excellent explanation provided by Professor Craig Bohren of Penn State University:
"First I'll give you the wrong explanation, which you can find here and there. It goes something like this. As everyone knows, scattering (by anything!) is always greater at the short wavelength end of the visible spectrum than at the longwave length end. Lord Rayleigh showed this, didn't he? Thus to obtain the greatest penetration of light through fog, you should use the longest wavelength possible. Red is obviously unsuitable because it is used for stop lights. So you compromise and use yellow instead. This explanation is flawed for more than one reason.

Fog droplets are, on average, smaller than cloud droplets, but they still are huge compared with the wavelengths of visible light. Thus scattering of such light by fog is essentially wavelength independent. Unfortunately, many people learn (without caveats) Rayleigh's scattering law and then assume that it applies to everything. They did not learn that this law is limited to scatterers small compared with the wavelength and at wavelengths far from strong absorption.

The second flaw is that in order to get yellow light in the first place you need a filter. Note that yellow fog lights were in use when the only available headlights were incandescent lamps. If you place a filter over a white headlight, you get less transmitted light, and there goes your increased penetration down the drain. There are two possible explanations for yellow fog lights. One is that the first designers of such lights were mislead because they did not understand the limitations of Rayleigh's scattering law and did not know the size distribution of fog droplets. The other explanation is that someone deemed it desirable to make fog lights yellow as a way of signalling to other drivers that visibility is poor and thus caution is in order.


the reasoning behind the selection of yellow as a fog light color had nothing to do with physics. I've heard two reasons cited as the rationale behind the use of yellow fog lamps: (1) yellow lamps suffer less backscatter into the eyes of the car's driver than blue or green, allowing them to see better in the fog; (2) yellow lamps are more readily seen by an oncoming driver, so that a car with fog lights on will be seen more readily than white lights would be. The first point is true for light scattered off very tiny aerosol particles in fog -- blue light is scattered out of the path from the sun to the viewer of a sunset, leaving white light minus blue to reach the observer... so he/ she sees yellow/red -- but is pretty irrelevant for the kind of yellow lights used for fog lamps. Those lamps were generally made by putting yellow filters over a hot tungsten filament incandescent lamp, so that a lot of light is lost in trying to make the yellow light -- reducing the brightness available for the driver to see, which is not such a good idea. Using a halogen gas fill increases the brightness of the bulb, but the same general principle of reduced brightness still holds. Additionally, the size of water drops in fog is generally not appropriate for producing the kind of scattering I mentioned above -- if so, headlights would appear very red to oncoming traffic, which they don't. The second point, that the yellow color is more visible to oncoming traffic is also true, but irrelevant as well. The point of fog lights is to allow the car's driver to see better, not to be seen better -- if you wanted to be seen better, a flashing strobe would be more effective, but you don't see much of those in the fog light business. Most likely, the real reason that people have used fog lamps that are yellow is that they look so cool.



This article is provided as a public service by the Geophysical Institute, University of Alaska Fairbanks, in cooperation with the UAF research community. Larry Gedney is a seismologist at the Institute. I was asked the other day why fog lights were yellow. When I couldn't come up with an answer, I started asking around and discovered, to my surprise, that apparently nobody else could either. Skiers, shooters and other outdoor types have long known that yellow goggles or glasses enhance outdoor vision. This is because the yellow lenses filter out the blue part of the spectrum and increase the contrast of a scene. But does the same thing hold the other way around? With the goggles, we are filtering reflected light entering our eyes, but is it possible to illuminate something with yellow light and achieve similar results? The answer, apparently, is no (which is likely to raise strong objections from people who have been using yellow fog lights for years). For expert advice, I contacted the Cold Regions Research and Engineering Laboratory (CRREL) on Fort Wainwright. Captain John Craig of that group then arranged to have a computer search made on the subject of light penetration in fog and mist from CRREL's headquarters in Hanover, New Hampshire. As a result, I obtained a list of over 200 references and abstracts of articles published by researchers all over the world. Not a single one asserted that yellow light has superior penetrating qualities, but several specifically stated that it did not. To quote from one Russian article, for example: "Investigations and practices of automobile traffic do not confirm any substantial advantages of yellow light over white light. The advantages ascribed to it may take place only in very thin fog or may be subjectively received by some drivers owing to their individual peculiarities of vision. Therefore, it does not make any sense to switch over headlights to yellow light, although the use of yellow light in special fog lights does not raise any objections." End of quote. The phrasing is quaint, but the meaning is clear. I had long thought that the yellow sodium-vapor street lamps that are becoming common were used specifically because they cut through fog better. I found out that there actually is a specific reason for their use, but that it is because they operate on only about half the power of conventional lamps. So, unless you just happen to like yellow, save your money and forget about so-called "fog-lights." They don't exist.

QUOTE]Did you research anything from Europe? You might find some studies there.

Sent from my SM-G975U using Tapatalk
 

Registered
2020 Premium 6MT
Joined
1,471 Posts
When I got mine, the backlight was not an option. I think it's just for looks though, kind of like angel eyes you see on some cars.

And I agree, that while being a lot brighter might be really good off road, on the street it might bring some unwanted attention. The beam pattern is excellent, I put yellow ones in my kids truck and they really looked nice!
What is with this 5202 DT 2-pin and 4-pin adaptor options? Do I need either of these?
 

Registered
2015 XV Crosstrek Premium CVT, 2019 Impreza Sport MT, 2001 Forester S 4EAT, 2013 Outback Premium CVT
Joined
256 Posts
What is with this 5202 DT 2-pin and 4-pin adaptor options? Do I need either of these?
When I ordered my kit, it came with the adapters and mounting ring. Still, to be sure I'd either give DD a call or send a message. One thing about the company, they have excellent customer service. They are very responsive and are happy to answer any questions.
 

Registered
2020 Premium 6MT
Joined
1,471 Posts
When I ordered my kit, it came with the adapters and mounting ring. Still, to be sure I'd either give DD a call or send a message. One thing about the company, they have excellent customer service. They are very responsive and are happy to answer any questions.
Hmmm. Before I order, I'm looking at my 2020 Crosstrek and trying to figure out the best way to access these lights. It looks like there are these snap rivets holding these plastic pieces under the car acting as "shields" which I need to remove. Is there a special tool I need to remove these snap rivets? Using a large screwdriver and channel locks doesn't do the trick and I'm already mangling the plastic. DD has a video for the 2019, however my 2020 looks a bit different.

Thanks!
 

Registered
2015 XV Crosstrek Premium CVT, 2019 Impreza Sport MT, 2001 Forester S 4EAT, 2013 Outback Premium CVT
Joined
256 Posts
Do you have any photos of what yours looks like? There are special tools for trim. I have them but half the time I just use a small and large flat blade screwdriver.
 

Resident topic drifter
'18 and '19 Crosstrek Limiteds
Joined
16,210 Posts
Do you have any photos of what yours looks like? There are special tools for trim. I have them but half the time I just use a small and large flat blade screwdriver.
I have a set of plastic spudgers. You can easily damage plastic trim with metal tools...
 

Registered
2020 Premium 6MT
Joined
1,471 Posts
Do you have any photos of what yours looks like? There are special tools for trim. I have them but half the time I just use a small and large flat blade screwdriver.
I'll take some pics tomorrow when it's light out and I can get some decent pics.

I have a set of plastic spudgers. You can easily damage plastic trim with metal tools...
Might I find one at the local auto store?
 

Registered
2020 Premium 6MT
Joined
1,471 Posts
Perhaps. I got mine online after researching removing trim. They don't last long, they get busted up. You'll be lucky if they last more than one attempt...
In other words, I should buy a few and consider them sacrificial items?
 

Registered
2020 Premium 6MT
Joined
1,471 Posts
Yes, sacrificial is a good term. Sometimes it takes two or three to release a panel...
Looking over the job, I'm not sure it's necessary to remove anything visible on the outside. The light looks accessible from underneath which involves removing the plastic shield below which isn't there to look pretty in the first place. I just don't want to break the pop rivets and not be able to snap them back in.
 

Registered
2020 Premium 6MT
Joined
1,471 Posts
Is it worth getting the whole kit with the reflectors:


.....as opposed to getting just the bulbs:


Would I notice a significant difference?
 

Registered
2022 Canadian Sport trim (6MT // 2.0 )
Joined
1,003 Posts
Yes. The latter fits OEM halogen fogs. It does provide a significant improvement with respect to stock, but it's limited by the original optics. The SS3s provide a significantly higher output. To each their own though - I have DD's fog LED bulbs only and find them sufficient.
 

Registered
Joined
387 Posts
Hmmm. This has me thinking again about doing this. Would be nice to have brighter fog lights.

But so many options - Sport, Pro, Max, Amber backlight YES/NO. I'm definitely interested in yellow rather than white.

For those of you who have tried these, which options did you choose? And what kind of wiring modifications were necessary? Was soldering necessary?
I did yellow sports, no backlight. Think thats going to be the most common. Completely plug n play.
 

Registered
Joined
70 Posts
Looking over the job, I'm not sure it's necessary to remove anything visible on the outside. The light looks accessible from underneath which involves removing the plastic shield below which isn't there to look pretty in the first place. I just don't want to break the pop rivets and not be able to snap them back in.
If you're removing the lamp assembly, you'll need to pull back the undertray and pull off the front trim. It's not difficult. Just use a plastic trim tool.

I replaced the lamps on my 2021 Limited with Baja Designs Squadrons (in wide cornering) using Paranoid Fabrication brackets and Deutsch wiring adapters. Pretty easy. I use them for spotting animals at night since deer (also known as 'tall forest rats') are plentiful around here.
 
21 - 40 of 59 Posts
Top