MacGregorSailors.com

If you replace bow lights with LED, you should not put a white light behind a colored lens like you do with an incandescent light. Instead, put a red LED behind the red lens and a green LED behind the green lens.
SILK

great story fishhead...lol

I would think it would be against the code to be sailing/running with a red light only on the bow illuminated, wouldn't it? It would mess up the red/green 135-degree rule? Perhaps only when docking/mooring or something like that? Someone 'splain, please. Thanks.

Night vision in humans actually takes hours to acquire, and is the result of biochemical changes that occur in the retina.

The adjustment that the eye makes for changes in light intensity by opening and closing of the iris takes just seconds.

Since it takes hours to acquire (and just seconds of bright white light to destroy) people who need night vision for critical purposes (deep-sky telescope work, flying, marine navigation, photo darkroom work) will start the process early using dark glasses , precisely as Bob’s described for us.

If you are navigating by dead reckoning and map reading at night, you will want to look outside the cockpit and be able to see in the darkness, and still look back and read your map, and you will be better able to do that under red light. And you want to see that big tanker bearing down on you fast, or the deadhead floating at the surface.

Using a red light to see during this time allows you to illuminate things enough that you can see them, but not enough that it destroys the accumulating night vision when you look away.

The concentration of cones (colour vision) in the retina is highest in the centre of the field of vision, and the concentration of rods (black and white) is higher outside this area. Which is why when you want to see something more clearly under dim light conditions you need to look just to the side of it, and not directly at it.

You can’t see past the campfire because your pupil has constricted because the light is bright, and you cannot force it to dilate as long as the light in front of you is bright. Look away from the campfire into the darkness (and/or close your eyes) and your pupils will dilate after a few seconds, and then you will be able to see better in the dark.

Unless you have looked directly into the fire. Then it’s your retina that takes time to adjust, maybe a minute to see reasonably well, or hours for best night vision, as I mentioned above.

Putting a red (or green) filter in front of a white light source (conventional, incandescent ) will filter out all colours of light and allow just the red (or green) to pass through. But it does dim it when it prevents all the other colours from passing. Turns them to heat = inefficient.

Coloured LEDs do not produce white light – they produce their colour, and ONLY their colour, so no filtration is required. Look closely at red LED and you will notice that it is actually white when it’s not on. That’s one reason (there are others) that you do not want to dim an LED by placing coloured filters in front of it.

Regards- Brian.

Ps. OK, for the didactics; the red light for photographers IS also because photo paper, and some graphic arts films, are not as sensitive to the long wavelengths (red) of light, so it allows you to work with them and still see what you’re doing in a darkroom.

i have white LED's behind my cheap red and green macg bow light and it works just fine, no noticable difference from the old incandecent bulb, so don't waste ur time trying to find red and green led's,all bow lights ive seen use only one bulb to light both lens so unless your installing new lights seperately on each side of the boat u counldnt use colored leds anyway.

You guys are great. Now I know why when I walk into a 'dancing establishment' on a bright sunny day, it takes me 10 minutes to make out what the dancers look like. Well that only happend 20 years ago of coarse.

I will be buying a single white LED for the bow light and thankyou for all your knowledge.

Shanker

According to the website http://www.superbrightleds.com

"For best results the LED color should be the same as the lens color or if bulb is behind a clear lens, use the appropriate color for turn and brake light functions. As an example: a red lens will filter out all but the red portion of the light so if the light is all red, none or very little light will be blocked by the lens. The light from a White LED contains very little light in the red portion of the visible spectrum so most of the light would be filtered out by a red lens."

Although this note was in the section on car bulbs, I would think it would hold for boats as well. Although the light might appear bright enough up close, don't forget that you have to see the bow lights for at least a mile away. Using a red LED and green LED might be a good idea.

SILK

i used the superbright 12 led 41mm festoon bulb(superbright has very good prices) in the standard (hella) macgregor bow light fixture.visibility is excellent at two miles out . I would imagine their "for best results "reccomendation about red and green colors is more of a marketing ploy aimed at a gullible market in order to sell more of their product. Kinda like battery manufacturws advising people to always replace all your battery's together,dont mix new with old.what do you think a company who maintains a large battery bank of say 2-3 hundred batterys is going to do when one goes bad, i promise you they are not buying 200 new batterys.

All LED chips produce only a single wavelength of light, whatever they're made for at the factory. White LED bulbs are actually a combination of a red, a blue, and a green LEDs that are tuned to deliver the same power, hence white. It's usually a bit bluish and has a high color temperature of about 8000 Kelvins. "Warm white" LED also incorporate a 4th yellow LED to bring down the color temperature to 3000K or so, which people tend to like better. Nowdays all three or four LEDs are etched onto the same chip.

You aren't getting "broad spectrum" light like the sun or an incandescent light, you're getting three (or four) specific wavelengths that are very bright. If you split white LED light with a prism, you'll see the specific green, blue, and red component lines sharply, not at all like the "rainbow" you'd get from broad spectrum light. This means that colors like purple and orange won't appear exactly correctly under LED lighting, but it's not an important effect unless you really care about color accuracy.

When you put a white LED behind a red or green lens, you're passing 100% of the red LED light and close to 0% of the blue or green. It only matters if you care that you're wasting 2/3s of the electricity going out of the LED and turning it into heat inside the colored lens. White LEDs used to cost more than other colors because blue was difficult to produce and because they have three LEDs in a cluster, but those costs are now small and usually gone by the time the LED has been incorporated into a product.

In sum, red and green LEDs will conserve considerably more battery for the same brightness in your nav lights, but white works just fine if you don't care about that.

Nice post Mastreb!

Yeah, the thing about types of lighting like LED's - that trick the eye with "color-frequency-peaks", as you describe, is that the eye is only 100% fooled when you look at the lightbulb itself. IOW - lt looks like a nice bright-white, or warm-white color (whatever you've chosen). But, if that light is illuminating an object that doesn't necessarily reflect those colors of light, the object will look strange and have very different hues . If you hold these LED lights up to your face, you'll notice that you look pretty ghastly compared to when you're illuminated by an incandescent light. At the same time, the two types of lightbulbs themsleves seem to be giving off similar light.

I keep both bulb types handy on my boat and only pull out the LED's when I'm on an overnighter, or weekend trip.

~Bob

I took the lenses off my bow and stern lights. They were both faded a little. The first pic shows the before view.
http://i1109.photobucket.com/albums/h42 ... tylens.jpg

I then polished the plastic lenses. The next pic is the after shot.
http://i1109.photobucket.com/albums/h42 ... htlens.jpg

In person, the cleaning shows very well. I don't know if it shows clearly enough in the photos but it made a dramatic difference to the overall appearance. The dull, slightly yellow hue is gone and they now have a beautiful clear aspect to them. Recently, I polished the dull headlights of my daughters 95 Interpid and they came out very well making them look brand new again. Believe it or not I used toothpaste on one of them and on the other I used Meguiar's PlastX polish. I did a comparison and although both did a very good job the Meguiar was slightly clearer. I used Autosol on the rear tail lights and it worked very well also. I don't have any pics of those so you'll have to take my word, but they look brand new. So that is what I did on these boat lenses. Here is a pic of the products used.
http://i1109.photobucket.com/albums/h42 ... agents.jpg


In order to clear up the issue of the red/green lens in the bow light for myself, I tried a little test. I took each lens and individually placed then on one of those LED pucks that you get from WallMart for $5.00. I turned off all the lights in the house and made some observations. The lights in the puck I would call 'cool white' as they do have a slight blue hue to them. The clear lense looked awesome. The green/red lens was interesting. The red lens was fine but the green lens definately looked more blue than green (upclose). I then placed the lighs so I could get as far away from them as possible and made some more observations. Again, the clear lens was awesome. The green/red lens was worse. The green looked more white than green. The red was OK, as you could tell it was red, although not as definate a red as it was up close.

To try to compare some more, I took a regular non-LED flashlight and performed the same test. The clear lens was fine, although not nearly as bright as the LED light. The green/red lens was interesting. Although it was not nearly as bright as the LED test, the red was definately red and the green was definately green. From upclose and at a distance both colors were definately more distinguishable as red and green. I realize this was not scientific but it definately gave me a better idea of how a lens will be affected by a LED light.

I have noticed that most folks claim that the warm white LED's give a better light than the cool white does. I normally hear that pertaining to cabin lights not for exterior lights but a warm white LED may have a more appealing result as far as the green/red lens. Again, not scientific and I'm sure there will be loads of issues with my process but it is what it is. I hope it helps some of you out if your buying LED's because thay are not cheap.

Shanker

I had a PM that asked me to show how I polished those little rascals. With all those ridges they did cause my fingers to cramp up. I needed an easier way. I had a polishing wheel attachement for my drill that I tried but its circular motion was not the best to get into some of those tight areas. I needed a mechanical recipricating action to properly accesss those tight areas. I pulled out my Bosch jigsaw and put it to work. I wrapped the blade withsome cloth, then turned it upside down and supported it with a quilt. Now the blade is pointing up. I rubbed some meguiar's polish on the cloth as well as the lens. I used the back side of the jig saw blade for obvious reasons. I turned on the jigsaw and polished away. A couple of key points: Use the slowest setting on the jigsaw, keep it lubricated and you don't have to use a lot a pressure. Nice and easy and let the polish do it's job. Here's a pic of my set up.

http://i1109.photobucket.com/albums/h42 ... ingjig.jpg

Shanker

That is certainly thinking outside of the box

Ray

shanker wrote:I used the back side of the jig saw blade for obvious reasons.

My favorite part!
The pics do show how nicely they cleaned up! Might have to do something like that myself. (I have also done the "polish the headlights" trick, and it works very well! It doesn't take out the little impact nicks from rocks/sand, but it takes the crazing/yellowing out and makes them look much better.)

This has been a very informative thread...I've learned a lot about LED lights!

I am getting the feeling that for an overnight, with a masthead-mounted anchor light on at night, a CD player, and perhaps using an interior light or two on-and-off during the night, there shouldn't be too much amp draw, and I should be able to sleep in peace...fair assessment? I can see the value of making the masthead anchor light an LED, since it is all white and will be on all night - but don't see the need for doing that to other lights at this point.

Nuther thought from all of this, since I don't live on the boat for weeks at a time, overnights at the most right now, I'm thinking of getting a few of the battery-powered led pucks from wallyworld, I should be good for quite a few months at a time to have "enough" light in many places throughout the boat without having to use the boat's lighting system...does that work from your experience? For example I'm considering adding one to the underside of the companionway stairs so going up/down at night is less treacherous, in the cockpit at the companionway, in the head, here, there, etc. For the cost of a handful of batteries, and as long as they should last from being used only as a day-sailer/weekender, I'm under the impression that we'll be okay for the overnights for quite some time...

Last idea is to also buy the hat-mounted/headstrap-mounted lights for walking around/working on the boat up on deck or in the cockpit (hands-free).

I'm sure that everyone practiced very good power management before LED's came out - probably quite a few posts about it in here, true?

Hey Shanker -Nice job! I love it - they look lika new!

I’ve polished plastic up with Brasso (or Silvo) metal polish – works well if you already have it on hand, and the abrasive is very fine. A good finish with plastic requires the right combination of heat and friction. Too much or too little and the job won’t turn out right (melt!) or will take forever! Plastic watch crystals that are lightly scratched will polish up like new with this in seconds.

Another way to do the polish job of the bow light lens for those who don’t have a jigsaw is to put a bolt through the centre of a cork which is sized so as to jam snugly into the light. Chuck the bolt into a fixed drill and polish away.

A similar, edged polisher to Shanker’s will get into the grooves, but an ink eraser, which can be shaped easily, will also do well for initial roughing. You can easily control the polish rate and heat buildup by varying your rpms and pressure. Keep it moving.

A long, thin piece of polish-impregnated cloth held across the lens between both hands while the drill is running will get into the bottom of the grooves as well. Wrap the cloth around maybe 180 degrees, but not more, because it can catch and grab, and wrap itself around. Not so bad, maybe, if you aren’t wearing a tie!

These polishing techniques also work well on the restoration of old car, boat, or motorcycle knobs and switches, particularly round ones. Age fading will often penetrate only a very small distance into them, and removing that thin layer to reveal the fresh material underneath can make them look like the day they left the factory (or actually better) for very little work.

- Brian.

In order to clear up the issue of the red/green lens in the bow light for myself, I tried a little test. I took each lens and individually placed then on one of those LED pucks that you get from WallMart for $5.00. I turned off all the lights in the house and made some observations. The lights in the puck I would call 'cool white' as they do have a slight blue hue to them. The clear lense looked awesome. The green/red lens was interesting. The red lens was fine but the green lens definately looked more blue than green (upclose). I then placed the lighs so I could get as far away from them as possible and made some more observations. Again, the clear lens was awesome. The green/red lens was worse. The green looked more white than green. The red was OK, as you could tell it was red, although not as definate a red as it was up close.

To try to compare some more, I took a regular non-LED flashlight and performed the same test. The clear lens was fine, although not nearly as bright as the LED light. The green/red lens was interesting. Although it was not nearly as bright as the LED test, the red was definately red and the green was definately green. From upclose and at a distance both colors were definately more distinguishable as red and green. I realize this was not scientific but it definately gave me a better idea of how a lens will be affected by a LED light.

I have noticed that most folks claim that the warm white LED's give a better light than the cool white does. I normally hear that pertaining to cabin lights not for exterior lights but a warm white LED may have a more appealing result as far as the green/red lens. Again, not scientific and I'm sure there will be loads of issues with my process but it is what it is. I hope it helps some of you out if your buying LED's because thay are not cheap.

Shanker

How the human eye sees it is the important factor in all of this, so in fact your experiment was entirely scientific. The washed out color is caused by the fact that the "green" lens is actually passing quite a bit of yellow and blue. With broad spectrum light, the yellow and blue add to the green, but because the cool white LED you used had no yellow component, and the red component was completely blocked by the green lens, you passed the green and the blue which shifted the overall color to something that I'm guessing looked like a murky cyan.

So this is actually about the quality of the filter lenses, and the fact that they're actually quite broad spectrum. You can get tighter filters scientifically, but they're way more expensive than red and green LEDs.

Use a actual red LED, and an actual green LED, and you'll get beautiful nav lights.

The human eye has been adapted to like broad-spectrum light. LEDs will always seem "ghastly", even when they're exactly the same color temperature as an incandescent. I have them at home, and I can tell you that the eye is not fooled--they're "harsh" even at the same color as incandescent.

But they use 1/10th the power, and that's damned important on a sailboat IMHO. You can get enough charge from a $100 solar charger in cloudy conditions to run your LED lights all night long, which is just as perpetual as the wind IMHO.