Fell running at night

[Fellhound]

Is it not because yellow is less likely to dazzle?

http://www.gi.alaska.edu/ScienceForum/ASF5/593.html

I'll have to check it out.

I think next time I go for a night run I'll have plenty of spare lights

Bill

Hmmm, interesting, but the final statement (that fog lights "don't exist") is plainly untrue. The main feature of a fog light for a car is its beam pattern. It gives a wide flat beam, to better illuminate the verges without dazzling. They are also best mounted low down (the automotive equivalent of carrying your headtorch in your hand) but yellow has been used for years because it is percieved to give better visibility in fog. That might be to do with peculiarities of the human eye but anyone who has had a Petzl Myo or Duo with LED and halogen (or even an old Zoom) will know that a yellowish light seems better in mist. It may be to do with dazzle though; - reflected yellow light doesn't dazzle as much as reflected white light!

Some experimentation is obviously required..... wonder if you can still buy that pale amber stuff you used to paint onto your headlights when going to France?

[cobbydale]

Hmmm, interesting, but the final statement (that fog lights "don't exist") is plainly untrue. The main feature of a fog light for a car is its beam pattern. It gives a wide flat beam, to better illuminate the verges without dazzling. They are also best mounted low down (the automotive equivalent of carrying your headtorch in your hand) but yellow has been used for years because it is percieved to give better visibility in fog. That might be to do with peculiarities of the human eye but anyone who has had a Petzl Myo or Duo with LED and halogen (or even an old Zoom) will know that a yellowish light seems better in mist. It may be to do with dazzle though; - reflected yellow light doesn't dazzle as much as reflected white light!

Some experimentation is obviously required..... wonder if you can still buy that pale amber stuff you used to paint onto your headlights when going to France?

Makes perfect sense Trundler

[Baggins]

anyone who has had a Petzl Myo or Duo with LED and halogen (or even an old Zoom) will know that a yellowish light seems better in mist. It may be to do with dazzle though; - reflected yellow light doesn't dazzle as much as reflected white light!

Some experimentation is obviously required..... wonder if you can still buy that pale amber stuff you used to paint onto your headlights when going to France?

I think it is to do with white light causing more dazzle rather than yellow light cutting through the mist.

Using a filter/paint will reduce the light output maybe not as much as my red filter does but it will be less.
It would be better using a torch with a halogen bulb to test the theory, I just happen to have a torch with said bulb all I need now is a night off work and some mist

Bill

[david]

Yellow fog lights? I haven't seen a car with yellow fog lights for about 30 years .

[Baggins]

Yellow fog lights? I haven't seen a car with yellow fog lights for about 30 years .

oops I think we're showing our ages here

Bill

[Fellhound]

Yellow fog lights? I haven't seen a car with yellow fog lights for about 30 years .

It's true that modern cars don't seem to have them but there are still plenty about, and companies like Cibie still make them (usually yellow bulbs rather than yellow glass though).

[Double Dee]

I think it is to do with white light causing more dazzle rather than yellow light cutting through the mist.

Using a filter/paint will reduce the light output maybe not as much as my red filter does but it will be less.
It would be better using a torch with a halogen bulb to test the theory, I just happen to have a torch with said bulb all I need now is a night off work and some mist

Bill

The Pennine group regularly run on the fells at night, but last Thursday saw some serious fog/mist. I run with a myo xp and can run at a quick pace under normal conditions, I was slowed to a shuffle by the fog until some of us decided to carry our torches at waist height, made about a 30% improvement in speed I think. I dont think it matters that much what colour your lense is then. Hope that helps. Looking forward to snow and clear nights again....

[macc ladd]

When it's foggy, it's definitely worth holding your headtorch in your hand. Makes a big difference. (Macc were out last Wednesday in the same conditions).

[Grouse]

Hey Double Dee are you that one who used to be in Legs and Co? Phwooaaarr!

[Grouse]

I had to carry my headtorch in my hand the other day cos I was getting a bit light-headed.