Please recommend a light to shine through water in a lake?

[TEEJ]

LOL

I would imagine that any concentrated blue beam would work then...not sure why the Q-Beam's would be special per se.

I don't remember blue as GOOD for penetrating water though, but that's just my own experience.


I'd go with polarizing lenses to look through though, being sure to rotate them so the orientation takes out the glare.

I've shined down into water with some fairly ordinary lights, and high cd and polarization go a long way all by themselves.

None of it works better than the light IN the water of course.




So, I would not add a filter to the light itself. Every time you add a layer, you cut the transmittance and reduce what color rendition you might have had.

Polarizers themselves cut your ability to see, as they are only letting in about half the light (To get rid of the glare). So, a strong cd light can overcome that 50% loss, and would not require further looses due to filters, etc.

 

[Kaban]

LOL

I would imagine that any concentrated blue beam would work then...not sure why the Q-Beam's would be special per se.

I'd go with polarizing lenses to look through though, being sure to rotate them so the orientation takes out the glare.

I've shined down into water with some fairly ordinary lights, and high cd and polarization go a long way all by themselves.

None of it works better than the light IN the water of course.




So, I would not add a filter to the light itself. Every time you add a layer, you cut the transmittance and reduce what color rendition you might have had.

Polarizers themselves cut your ability to see, as they are only letting in about half the light (To get rid of the glare). So, a strong cd light can overcome that 50% loss, and would not require further looses due to filters, etc.

Where are you getting the polarizing filters?

EDIT: What is CD?

 

[TEEJ]

Where are you getting the polarizing filters?

The easiest way is probably shooting glasses/night driving glasses. They tend to be a light gray or yellow...not sunglasses, those are also tinted.

If going with an HID, they have very short run times, typically ~ 20 min or so on high before they start to dim, and typically take a while to charge. If they have swappable batteries, you could pre-charge a bunch before heading to the pier, etc.

If the pier allows parking, and you could reach where needed with a cig cord, etc....you could run it off the cig lighter, etc.


If going with an LED light, they are typically good for 1-4 hours depending on the model and what cells you use, etc...and you would also pre-charge spares before heading out if going to be there long enough to need them.

 

[Kaban]

The easiest way is probably shooting glasses/night driving glasses. They tend to be a light gray or yellow...not sunglasses, those are also tinted.

If going with an HID, they have very short run times, typically ~ 20 min or so on high before they start to dim, and typically take a while to charge. If they have swappable batteries, you could pre-charge a bunch before heading to the pier, etc.

If the pier allows parking, and you could reach where needed with a cig cord, etc....you could run it off the cig lighter, etc.


If going with an LED light, they are typically good for 1-4 hours depending on the model and what cells you use, etc...and you would also pre-charge spares before heading out if going to be there long enough to need them.

Are you talking about getting polarized glasses? Or a polarized cover for the light? Very confused.

 

[EscapeVelocity]

I can't find the run time on the Brinkmann you suggested. I have a Brinkmann Maxfire with the dual head and incandescent bulbs... I kid you not, but the bulbs burnt out after about 10 hours of (noncontinuous) use. And replacement bulbs cost half the cost of the whole light/charger system. Overall a very cheap light. Looks like the one you are suggesting is probably the same crappy quality.

Do you personally have this light? It's an incan 2900 lumen light with what looks like a tiny battery pack. There is no way that's gonna run for 4 hours.

I suggest you get the older USA made Blue Max at 200,000 candlepower. Run that sucker off of an Automotive or Boat Battery with alligator clips. Itll last from dusk till dawn. The older light is made better, and draws less power whilst still giving plenty of penetrating light.

Just an option. There are great solutions being offered up in this thread. I like the Night Driving glasses idea as well.

 

[Kaban]

I suggest you get the older USA made Blue Max at 200,000 candlepower. Run that sucker off of an Automotive or Boat Battery with alligator clips. Itll last from dusk till dawn. The older light is made better, and draws less power whilst still giving plenty of penetrating light.

Good idea with the car battery. How long is the bulb life of it do you know?

 

[EscapeVelocity]

Are you talking about getting polarized glasses? Or a polarized cover for the light? Very confused.

Either would work. Glasses are easier and allow you to remove them at will, so are more flexible. The idea is to cut the glare bouncing up from the water into your eyes, and to keep your pupils dialated.

 

[Poppy]

I think (as others have said) its best to get the light below the surface to reduce the glare. If you have a helper, and you decide to put the light under the surface, you might consider attaching four lines to it, and attach them to a pair of sticks so that your helper can operate the flashlight like a marionette pupet. Direct it up and down, and left and right.

Another option may be to place it head down, but with "water wings" around it so that it will float on top, and hopefully not sink below it's 6-8 foot depth water proofing.

 

[EscapeVelocity]

I think (as others have said) its best to get the light below the surface to reduce the glare. If you have a helper, and you decide to put the light under the surface, you might consider attaching four lines to it, and attach them to a pair of sticks so that your helper can operate the flashlight like a marionette pupet. Direct it up and down, and left and right.

Another option may be to place it head down, but with "water wings" around it so that it will float on top, and hopefully not sink below it's 6-8 foot depth water proofing.

You could mount a light on a classic circular life preserver, maybe?

 

[TEEJ]

So much info here.

cd is a measure of the light's ability to throw...candella.

We don't SEE lumens, we only see lux. Lux is the light from the target bouncing back to our eyes.

cd is equal to the lux at one meter. (Shine the light at a lux meter a meter away, and get a reading...that's the lux at one meter)


(As some large lights don't have beam convergence until MANY meters away, you can't REALLY measure the lux at one meter...but, you can measure it at 20 meters and back calculate, etc..to get a STANDARDIZED lux at one meter, for comparison purposes)


The lux will drop according to the inverse square law...so, essentially, at twice the distance, it will be 1/4 as bright.

Lights with higher cd will be brighter (the targets will be lit up brighter) at a given distance than lights with a lower cd.

To SEE a fish, you might need about 2 lux or so to make it back to your eyes...BUT, I don't know how much of that light reflecting off the salmon, proportionally, will get back up to your eyes. The water diffracts the light, so its offset, plus, its absorbing light on the way back more than the air did, etc.

I have not done underwater lux measurements, so I would just say to maximize the cd as a blanket statement.

For the money, budget HID lights are going to give the highest cd unless you go for a DEFT-X, which would blow the doors off the wally world HID's in CD. (~ 900,000 cd)

The TN31mb is at ~ 400,000 cd, which is an amazing feat...but, still in some budget HID ranges.

Candle power is used to give a large impressive number, but a 5 million candle power light might only be a few hundred lumens, etc. (Candle power = cp, not the same as cd)

 

[ledmitter_nli]

You know, I looked into it, and I must ask, why you recommended this particular light? It seems extremely small and 180 lumens of light? I don't even see that touching the surface. I might as well just use my armytek predator than.

^^^ Fenix LD25 just got owned.

 

[DTF]

Looks like the pro way to go is a green submerged light not blue. Search on "fish light" and there are all sorts of references. If you don't want to use a submerged light, then I would think that the best option would be an aspherical lens flashlight with a green emitter or filter. Any sort of spill is just going to end up reflected back.

 

[jorn]

Blue or green should do the trix. I like a blue tinted one in my divelights.

"Water not only changes the color of sunlight, it dramatically changes its intensity. In clear ocean water, visible light decreases approximately 10-fold for every 75 m that you descend. This means that at 75 m the light is 10% as bright as it was at the surface; and at just twice that depth, 150 m, it is another 10-fold dimmer, or 1% of surface light."

Interesting read, quoted from: http://oceanexplorer.noaa.gov/explorations/04deepscope/background/deeplight/deeplight.html

 

[jorn]

ou know, I looked into it, and I must ask, why you recommended this particular light? It seems extremely small and 180 lumens of light? I don't even see that touching the surface.

this is like sayin something like: You only got 200 hp. I got 600 hp in my dumpster truck, so i bet i can drive in circles around your 200hp motorcycle
Something with 600hp won't always be faster than something with 200hp.

One of my best throwers is only ~200 lumens. Have lighted up some cabins at 650 meters with my ~ 200 lumen light. Just read what teej has to say. He is like a broken record on the lux-lumen debate. I dont blame him because way too many pepole dont get the difference between light intensety (lux) and total otuput (lumens). Teej is right, but educating pepole between lux and lumens is hard when flashlights are messured by lumens only 90% of the times, and with no lux numbers.

 

[EscapeVelocity]

I really appreciate the time and efforts of the knowledgeable to educate the noobs and masses. I have my specialties (not light technology) that I try to help others in as well, and it can be repetative and taxing, at times.

 

[ledmitter_nli]

this is like sayin something like: You only got 200 hp. I got 600 hp in my dumpster truck, so i bet i can drive in circles around your 200hp motorcycle
Something with 600hp won't always be faster than something with 200hp.

One of my best throwers is only ~200 lumens. Have lighted up some cabins at 650 meters with my ~ 200 lumen light. Just read what teej has to say. He is like a broken record on the lux-lumen debate. I dont blame him because way too many pepole dont get the difference between light intensety (lux) and total otuput (lumens). Teej is right, but educating pepole between lux and lumens is hard when flashlights are messured by lumens only 90% of the times, and with no lux numbers.

You understand we are talking about light passing through A COMPLETELY DIFFERENT MEDIUM (brackish water), right?

 

[Kaban]

Thank you for the additional responses.

Can someone please recommend specific lights now? Lights that would work well for this. The Brinkmann with a car battery so far is the best idea in this thread.

 

[jorn]

You understand we are talking about light passing through A COMPLETELY DIFFERENT MEDIUM (brackish water), right?

I know, and i spend mutch time in this "medium". Freediving fishing etc. lux is still lux and lumens is lumens. Even under water:huh:

 

[MikeAusC]

Polarising sunglasses allow you to see into water because they stop light that's been REFLECTED off the surface.

There's no benefit in aiming polarised light at the surface - if you get the angle wrong, all you'll do is reduce the light getting into the water.

 

[DTF]

I think the problem of using a flashlight to illuminate through water is not unlike trying to use a flashlight to illuminate the outdoors through a window. With any flashlight that has spill, all you see is the backscatter light/glare. Nothing can be seen outside, even if it might be illuminated. What works is a light reduced to a small circle. Such as seen with an aspherical flashlight. There is still backscatter but it's not nearly as much and the light clearly illuminated a spot 40 plus yards outdoors that could be easily seen through the window.

The Brinkman Q light is not designed to illuminate fish in the water. However, it would be better than a standard searchlight without the blue tinted front end. You can turn a Brinkman into a pretty good spotlight by placing a long tube (called a snoot) over the front end.