What is the best flashlight in the fog?

[Juggernaut]

No sealed-beam lantern? You're still playing in second division.

Wow, good read😀. I had no idea that this thread was still alive, after much reading I still have not seen any comparisons between old school sealed beam technology and modern LEDs. Let me see if I can shed some light on the issue. During the foggy season of my little rural town we often “almost every night” get some pretty bad fog up here “like when you can’t see 20 feet in front of you. I can tell you that such lights like the Tiablo A9 with collimator can not compete with the likes of the H7550 bulb. People must also understand that while the narrower the beam is, the better it cuts through the fog, aspheric LEDs can’t even compete with a properly built low wattage sealed beam bulb. The A9 aspheric produces a “230 L” 4.5 degree beam while the H7550 makes a 3x3 degree “150 L” beam, that’s much smaller. Also as I’ve stated above, once you get to a certain output “at least with cooler tints” you can not get any more range with more light. Example, with my Tiablo I went to one of the many local fields in my area, it is exactly 304 yards long. On a clear day I can easily light up the other side with my A9, but on a foggy day no matter how I hold the A9 “even as far away as my arm will let me, my line of sight will always intersect the very intense beam of light and obscure my view:shakehead. This technique does work at closer ranges, but not at 250+ yards. The 8 watt H7550 on the other hand could be held at eye level and I could see clearly through the beam and see the trees on the other side of the field. Take what you will from my observations, but that’s what I could see “and couldn’t😗”.

 

[Linger]

that is good Juggernaut, but imho it confirms the established point that light scattered close to your eyes illuminates the near fog and hides distant object.
A tightly focused light is better.

Does it go beyond that? Are there light sources (thus wavelengths) reflect less off fog?
This would really require the same set-up with different tints (for example if you just over-drove a bulb to increase colour temp and see if whiter is worse, by-product is increased lumen output so its an unclear test)

 

[Magic Matt]

I asked a friend of mine who works in the merchant navy about this. He came up with some interesting points.

First of all, he says Fog isn't white, it's slightly blue. Apparently red doesn't reflect as much as blue. In bad fog, they may turn off any white lighting "on-deck".

There's also a prism effect that splits the light. The yellow light stays relatively on-axis compared to blue that is scattered more off-axis, so because yellow stays more on-axis it "cuts through" more.

This makes sense to me, but I can't find any references to backup this info.

 

[Cataract]

I asked a friend of mine who works in the merchant navy about this. He came up with some interesting points.

First of all, he says Fog isn't white, it's slightly blue. Apparently red doesn't reflect as much as blue. In bad fog, they may turn off any white lighting "on-deck".

There's also a prism effect that splits the light. The yellow light stays relatively on-axis compared to blue that is scattered more off-axis, so because yellow stays more on-axis it "cuts through" more.

This makes sense to me, but I can't find any references to backup this info.

Reference or not, it makes a lot of sense and it's exactly the kind of information we need to take the experiments with fog to the next level.

I read somewhere (in a TK20 manual or papers that came with the red filter ?????) that red cuts through fog better. It is reflected less by the fog as I could experiment for myself, but a red filter is just that : a way to reduce the output from your light, so all I can say for sure about that is that mt TK20 or TK11 R2 could light up at the same distance with the red filter on, fog or no fog (which isn't all that far to start with).

The next level, IMO, would be to have a yellow, red and an orange emitter and see which of the three fares the best. I'm even willing to modify one of my own lights if anyone could recommend a good LED for the purpose. It might take a while before I see some fog again, mind you...

 

[Magic Matt]

It would be cheaper, and quicker, to use a neutral white LED and try some cheap photographic filters. You can usually find "Cokin" type filters cheaply, since a lot of photographers are dumping them since going digital.

 

[Juggernaut]

Next time, it’s foggy I’ll experiment with the “yellow” fog lens that came with my Oracle. Sadly the Oracle is not a very narrow beam orientated light, but for now I figure I’ll use it on high with the filter and low with out, that way hopefully the light out put will be similar “not the same I’m sure” but closer with the filter and with out. I’ll also try the filter with the Tiablo A9 to see if that may help at all. Though again it’s not exactly fog season right now🙁.

 

[OceanView]

he says Fog isn't white, it's slightly blue.

Interesting, I hadn't thought of that. But it makes sense since underwater, blue is the wavelength that can penetrate to the deepest depth.

 

[Sub_Umbra]

While very minor differences in fog penetration may exist between different beam tints I find it hard to believe that the disparity is great enough to make any usable difference in the real world -- in particular when compared to beam shape.

To put it another way, the differences in beam shape performance is so great that I doubt very much that a floody beam even of the optimal tint for the penetration of fog would outperform nearly any other color of equal power in a tight, tight beam shape with no spill held on the target nonparallel to the line of sight.

 

[Cataract]

It would be cheaper, and quicker, to use a neutral white LED and try some cheap photographic filters. You can usually find "Cokin" type filters cheaply, since a lot of photographers are dumping them since going digital.

The problem with filters is that you usually loose a lot of light, depending on the color of your lens and the spectrum emitted by your flashlight. I'm suspecting that yellow or orange filters might give a much more interesting result than red filters with neutral lights

Next time, it’s foggy I’ll experiment with the “yellow” fog lens that came with my Oracle. Sadly the Oracle is not a very narrow beam orientated light, (...)

I have been trying to get rid of spill lately by making a simple paper tube that I slide onto my flashlight... it works to a certain degree, but if you make it too long you then loose some intensity in the spot as well. Maybe you could try that and see if it makes any difference. We don't get much fog here, especially in winter, so it might take a while before I can try it myself...

 

[asdalton]

There's also a prism effect that splits the light. The yellow light stays relatively on-axis compared to blue that is scattered more off-axis, so because yellow stays more on-axis it "cuts through" more.

That's true for a single refraction (as with a rainbow), but the reason that fog obscures vision is that you have multiple reflections and refractions that scatter light in random directions. This random scattering will negate the slight differences in the bending of different colors of light scattering from any single droplet.

 

[Juggernaut]

I have been trying to get rid of spill lately by making a simple paper tube that I slide onto my flashlight... it works to a certain degree, but if you make it too long you then loose some intensity in the spot as well. Maybe you could try that and see if it makes any difference. We don't get much fog here, especially in winter, so it might take a while before I can try it myself...

Yes I may try that:thumbsup: or one of the other “spill reducing” ideas mentioned earlier in the thread, however even with little side spill the Oracle 35 watt still produces low lux when compared to some of my other lights, again for example the H7550 easily out throws it with only >150 lumens.

 

[DM51]

Best flashlight in the fog? Well, I know a Barnburner is NOT much good, lol. I've just taken delivery of one and I've been keen to get out and get some beamshots... but it's been solid FOG here for the last few days. Shine a big light like this into fog, and it's like hitting a white wall.

 

[Linger]

I've been keen to get out and get some beamshots... but it's been solid FOG here for the last few days. Shine a big light like this into fog, and it's like hitting a white wall.

Sounds perfect!
Maybe break out 'The Moderator,' some M6 configurations, a few m@g mods as well. Ideally one or two dozen led's of similar configurations but different tints. 🙂

 

[Magic Matt]

That's true for a single refraction (as with a rainbow), but the reason that fog obscures vision is that you have multiple reflections and refractions that scatter light in random directions. This random scattering will negate the slight differences in the bending of different colors of light scattering from any single droplet.

Are you sure it wouldn't accentuate it?

I wish I had some different coloured lasers to try, it would be interesting to see how they are affected by fog from a side-profile beam shot.

 

[Icebreak]

Two lights of similar lux.

I don't remember the settings but the camera is set to make both beams have terrible color. That's fair isn't it? This is a fairly foggy night. It was rolling in like a big cloud. Nothing at all like the chewier fog that can be experienced on the coasts. Fairly close, like 60 feet or so the tight beamed LED appears to not only keep up with but surpass the incandescent spotlight in lux. However at a greater distance 60 yards (or meters) there is an evening of the competition with an odd phenomenon.

The bluish LED beam stacks up and makes what appears to be a glowing wall preceding the target. The yellowish Incan beam all but disappears leaving its light almost exclusively illuminating the target.

Here's an inexpensive but overdriven and very tight R2:

Here's an inexpensive non-modified Eveready incan spotlight.

Tight R2 at greater than 60 yards illuminating heavy equipment.

Non-overdriven incan spotlight at greater than 60 yards illumimating heavy equipment.

This is just one example of two lights on one particular foggy night. It may not hold true in all cases. I can tell you that the LED is surprisingly intense but the reflection of the beam in the fog was a distraction for my eyes.

This GIF may or may not serve to illustrate the distracting nature of the reflective light the fog returns to an LED source as opposed to how the fog reacts to a very similar incandescent source.

 

[alpg88]

easiest way ,get a auto fog light kit, hook it to a 12v battery, that is it.
you could also change a bulb for lower wattage, so you have longer runtime

 

[defloyd77]

easiest way ,get a auto fog light kit, hook it to a 12v battery, that is it.
you could also change a bulb for lower wattage, so you have longer runtime

Not quite, where are we going to mount them? On our shins?

 

[alpg88]

Not quite, where are we going to mount them? On our shins?

use your imagination, be creative, :duh2:
i made few lights from automotive lights, back in the days when there was not much else to work with, it came out not bad at all, turned out to be handy searchlights.
todays kit lights for cars a lot more lighter and smaller. you don't have to use led acid or nicd batteries, now there is a lot more possibilities,
another question is it the best way??? idk , but one thing is for sure lights will be made specifically for fog

 

[Magic Matt]

This GIF may or may not serve to illustrate the distracting nature of the reflective light the fog returns to an LED source as opposed to how the fog reacts to a very similar incandescent source.

There is no way that those light sources could be considered 'similar'. One is blue, the other is orange, and we already know that beam colour is a factor. To do a valid comparison, you need two light sources that are at least almost the same colouring. Blue tinted incans are crap in fog, unless you're deliberately trying to light a beam into the sky.

 

[Icebreak]

They are both tight beams with similar intensity or lux. Of, course they are not the same. One is LED. The other is incandescent. And the bluish one is not a blue incandescent.