Two experimental flashlights for muddy water

[Z-Max]

I have this idea after reading part of german scientist Peter Kronberg "Remote sensing the Earth" (1985).
Idea: longwave light is better for penetration in muddy water.

First flashlight:

LEDs: 5x XPE amber (monochromatic 585-595 nm)and central XPG 4000 K.
Summary: 420 Lm of amber light and 320 Lm of white light.

3 different mode:
3 amber XPE

5 amber XPE

and all leds

Second flashlight:

LEDs: 6 XPE amber and central XML 3000 K.
Summary: 562 Lm of amber lihgt and 480 Lm of warm white.

Powered by bFlex.

Additional: have 3 modes:
1. 3 XPE
2. 6 XPE
3. 6 XPE and XML

Ring with magnet and magnetic switches may change output circuit of the driver

Before I made flashlight with red-orange leds XPE:

it was pleasant to me too

 

[eebowler]

I believe the same is true for fog, smoke, mist etc. NICE LIGHT!! Did you test out in working conditions as yet?

 

[Z-Max]

Did you test out in working conditions as yet?

certainly.
In the beginning it is unusual but I have quickly got used to light. Good contrast.
One moment: eye's pupil remains widely opened.

 

[Packhorse]

Isnt one of the first things you learn in OW is that red and orange light is absorbed quicker than green and blue light.

Best penetration is a light coloured same colour as the water.

Nice project in other regards though.

 

[MikeAusC]

But if I look at David Attenborough videos taken at the bottom of muddy streams, all I see is brown light i.e. the only light that passes through is at the red end of the spectrum.

" the same is true for fog, smoke, mist etc" - when I look at the headlights of oncoming cars through fog, their light is still white i.e. all colours are transmitted equally.

 

[DIWdiver]

If you are talking about penetrating murky water, it's very different from penetrating clear water.

Clear water absorbs the reds, oranges, yellows first, leaving the only bluish light at depths around than 30-ish feet or more. It's the actual water itself doing this.

But in turbid water where light has a hard time penetrating 5 or 10 feet, it's stuff in the water that's the problem, not the water itself, and the penetration capabilities of different colors could be completely different.

I wouldn't be quick to doubt Z-Max's ideas based on well-accepted but perhaps unrelated facts, but rather eager to see his field results. I think it's great that someone is using technology, whether established or emerging, in a new way to try to solve an old problem. Given that monochromatic light is becoming highly efficient, I applaud Z-Max for experimenting with it to see if it can improve a diver's ability to see in poor conditions.

Z-Max, please say more about your experience diving with this light. And if you get a hankering to try different colors, please post the results here!

 

[AnAppleSnail]

I imagine a few beamshots in murky water would suffice. Let's say that you run a black-and-white stick out into muddy water and use a camera (or heck, just tell us what you see through swim goggles). To average out the muddiness, maybe do a repeated test. The 'proper' way to do this is to come up with an experiment matrix, then do those setups in random order. Let's say you had:

1, Red light
2, Amber light
3, White aspheric
4, White regular

It's elementary to list the combinations:
1 vs 2
1 vs 3
1 vs 4
2 vs 3
2 vs 4
3 vs 4

Then you might do those pairs in this order, and note how far down your stripe stick you can see (To 5th white mark, etc) with the light. You might have to do this test at night to avoid sunlight's effects.
1st, 3d, 6th, 2nd, 5th, 4th.

Then we might find that, say:

Red beats Amber beats White aspheric beats White regular.

 

[Codiak]

Clear water absorbs the reds, oranges, yellows first, leaving the only bluish light at depths around than 30-ish feet or more. It's the actual water itself doing this.

Just to be clear it's the distance the travels through water, not the actual depth. 30ft is close enough

But in turbid water where light has a hard time penetrating 5 or 10 feet, it's stuff in the water that's the problem, not the water itself, and the penetration capabilities of different colors could be completely different.

True, but the water is still the issue at 30ft of throw.
Particulate matter suspended in the water will decrease light penetration even more.

I wouldn't be quick to doubt Z-Max's ideas based on well-accepted but perhaps unrelated facts, but rather eager to see his field results. I think it's great that someone is using technology, whether established or emerging, in a new way to try to solve an old problem. Given that monochromatic light is becoming highly efficient, I applaud Z-Max for experimenting with it to see if it can improve a diver's ability to see in poor conditions.

Z-Max, please say more about your experience diving with this light. And if you get a hankering to try different colors, please post the results here!

I whole hardly concur with supporting the scientific method.

He has a theory, built a prototype, conducted some proof of concepts.... Let's see some beam shots for peer review.

I love that it's sparked debate and discussion beyond lumen output ;)

 

[Z-Max]

For understanding :) I more interest for spearfishing. In my country it is lawful - night spearfishing in rivers and lakes. River's water usualy is muddy in the summer. Because I have big expirience :) (2-3 dive in the week ).

As for me for distance 0-3-4 meters main problem of lighting is not absorbe but is reflection from suspension back to eye.

First ideas i have in the car in fog. And with experiments with warm diodes. So I have question "Why as for me warm and very warm (2500-2700 K) light better in muddy water then cold and neutral lights". After reading the book about distance learning I build first flashlight (3 XPE red-orange). It has made upon me the big impression.
Main victory is much less reflection from suspension and better visibility and contrast thanks to it.

For adequate display I need professional camera.
Unfortunately I haven't it :(

Amateur camera not adequate display. I try :) but i think after video you have more questions then answers:


Amateur camera have too low sensitive and made unrealistic colour.

This flashlight on the video:

 

[lucca brassi]

That video reminds me on our lake ( old submerged brown coil mine) , very big fishes (carp , pikes and catfish ) inside but low vis like coffe , don't like to dive there and you get also ''smell'' ;-).

Nice light , surface is burned powderpaint ?

 

[Ferradinho]

Very interesting concept.

 

[Z-Max]

Next concept:

LEDs:
18 XPE red-orange
1 SST-90 red

total: 3600 Lm (2600 Lm XPE + 1000 Lm SST-90)
43 W

Can work with and without lens for XPE.