LED Nav Lights

[rotrax]

The problem is the arc of illumination will be wrong. The colour is also likely to be incorrect.
The anchor light is the only one that will be satisfactory.

Less likely if you choose LED bulbs with coloured segments. I know it is only subjective but our bicolour is brighter and has very clear red and green differential segments with a bicolour LED bulb than with the 21w filament bulb. It is also,in my opinion,acceptable with a white led bulb fitted.

 

[Adrian Jones]

The problem is the arc of illumination will be wrong. The colour is also likely to be incorrect.
The anchor light is the only one that will be satisfactory.

There is all sorts of misunderstandings in respect of LED lighting that ebb and flow through the forums. An understanding of some basic principles always helps boat owners make informed decisions!

Incandescent Bulbs:-

Red and green lenses on our boats are basically filters designed to only allow red and green light to pass through. You will have noticed, for instance, that tri colour navigation lights often have a 10W incandescent lamp behind the clear lens but require a 25W behind the combined Red/Green lens. The reason for this is that an incandescent bulb actually produces relatively low levels of green wavelength light and therefore needs the higher wattage lamp to generate just enough green wave length light to pass through the lens to meet the green light visibility standard required. An incandescent light produces more than adequate red wavelength light, so meeting the red visibility standard is not a problem

LED Bulbs:-

When a green LED lamp is placed behind a green lens almost all of the light output passes through the lens resulting in a very bright green light. The same is true of a red LED lamp behind a red lens. So it is easy….use green LEDs behind green lenses and red LEDs behind red lenses.
White LED lamps are a special case as they can and are manufactured to produce different colours of white light Colours can vary from a yellow toned warm white to a blue toned cool white.
All white LED lamps start off as a blue LED, the difference in lamp colour is created by adding phosphor elements to the LED.

Warm White LED Bulbs:-

If red and green phosphor elements are added to a blue LED we create a warm white LED lamp. Blue light is absorbed by the phosphors and re emitted as green and red light. This is exactly what we want for our dual lenses as adequate red and green light is produced and can pass through the coloured lenses to meet visibility standards. So for bicoloured lenses use warm white LED lamps to produce satisfactory output colours and intensity.

Cool White Led Bulbs:-

Cool white LEDs have added phosphor elements that result in a relatively high intensity output in the blue wavelength, relative to green. This results in a blue green tinge when placed behind coloured lenses and the reason not to use cool white LED bulbs behind bicoloured lenses.
The light output from cool white LEDs appears whiter and brighter than warm white LED lamps and is therefore ideal for use behind clear lenses used for anchor, steaming and stern lights.

Hope this helps.

 

[noelex]

There is all sorts of misunderstandings in respect of LED lighting that ebb and flow through the forums. An understanding of some basic principles always helps boat owners make informed decisions!
.

There is no misunderstanding If an incandescent globe is replaced with its LED alternative, the large form factor of replacement LED “globes” is always going to result in a different arc of illumination than the line source of a filament globe.

Colour rendition is a more complex subject. The narrow spectral distribution of LEDs results in unpredictable effects when placed behind a filter designed for the broad spectral distribution of a filament globe.

Where the resulting combination falls in the CIE chromaticity coordinates. How the Led replacement will be perceived by colour defective observers etc is impossible to predict.

Judging by the appearance of these replacement LEDs the colour spectrum is often very wrong.

The practical effects of these differences are often, but not always, significant in the real world, but they can provide a mechanism for legal problems in the event of a collision. Given the wide availability of LED navigational lights and the relative low cost. I think these are preferable to use these rather than replacement LED “globes”. The exception is anchor lights where the arc of illumination (360 degrees) and colour ( a liberal interpretation of white) are easily reproduced by a replacement LED globe, in a fitting designed for an incandescent globe

 

[Adrian Jones]

There is no misunderstanding If an incandescent globe is replaced with its LED alternative, the large form factor of replacement LED “globes” is always going to result in a different arc of illumination than the line source of a filament globe.

Colour rendition is a more complex subject. The narrow spectral distribution of LEDs results in unpredictable effects when placed behind a filter designed for the broad spectral distribution of a filament globe.

Where the resulting combination falls in the CIE chromaticity coordinates. How the Led replacement will be perceived by colour defective observers etc is impossible to predict.

Judging by the appearance of these replacement LEDs the colour spectrum is often very wrong.

The practical effects of these differences are often, but not always, significant in the real world, but they can provide a mechanism for legal problems in the event of a collision. Given the wide availability of LED navigational lights and the relative low cost. I think these are preferable to use these rather than replacement LED “globes”. The exception is anchor lights where the arc of illumination (360 degrees) and colour ( a liberal interpretation of white) are easily reproduced by a replacement LED globe, in a fitting designed for an incandescent globe

Another old chestnut, legal problems with using retrofitted LEDs. I would be astonished if any court would be persuaded that a bright red or green LED lamp would be a significant contribution into a collision. Given the number of LED retrofitted lamps in service one would surely be aware of an actual case world wide. Maybe other forum members know of one case where such lamps have been deemed to be a factor in the cause of a colliision. My research has not highlighted any.

Most people i have spoken to consider LED purpose made fixtures to be prohibitely expensive! The cheap ones often have an increased failure rate due to not having adequate current control circuits.

 

[JimC]

I have retrofitted an Ultraleds warm white 18 LED bulb to my Aquasignal masthead tricolour. The red & green are as they should be and the brightness is at least up to average standards. The cut off between red & green is not as sharp as with a vertical filament bulb but this doesn't really amount to an "area of ambiguity" as over the few affected degrees one sees half red & half green so it's pretty obvious the vessel is bows-on to the viewer. One often sees the same effect when separate red & green lights are fitted either side of a pulpit. Overall I'm happy with the result and will feel safer displaying a bright LED light than a fading filament bulb caused by a fading battery or (worse) no light at all because the filament's blown.

 

[rotrax]

I have retrofitted an Ultraleds warm white 18 LED bulb to my Aquasignal masthead tricolour. The red & green are as they should be and the brightness is at least up to average standards. The cut off between red & green is not as sharp as with a vertical filament bulb but this doesn't really amount to an "area of ambiguity" as over the few affected degrees one sees half red & half green so it's pretty obvious the vessel is bows-on to the viewer. One often sees the same effect when separate red & green lights are fitted either side of a pulpit. Overall I'm happy with the result and will feel safer displaying a bright LED light than a fading filament bulb caused by a fading battery or (worse) no light at all because the filament's blown.

My conclusion also-the cut off between red and green is of little significance in the real world for the reasons you state. I can not concieve of a situation where my arrangement of replacement LED bulbs will put our vessel at risk if they are illuminated. As they draw so little from the batteries they should stay illuminated for longer while under sail with no charging from the engine. As I see it its win win.

 

[Adrian Jones]

My conclusion also-the cut off between red and green is of little significance in the real world for the reasons you state. I can not concieve of a situation where my arrangement of replacement LED bulbs will put our vessel at risk if they are illuminated. As they draw so little from the batteries they should stay illuminated for longer while under sail with no charging from the engine. As I see it its win win.

I fully agree with your observation in respect of LED bulbs not putting your vessel at risk. All too often boats continue using aged incandescent lamps, often with black tungsten coated glass and a light output at least 30% less than when new. The same boat owners are reassured that they have regulatory compliant lighting!

I'm interested that you say that the LED lamp has affected the cut off between Red and green lenses on your bi-colour fixture. I presume that you replaced a single 25W incandescent lamp with a warm white 18SMD LED. If so I really can't see that, in practice, the visual output using the LED lamp would be any different from that of the incandescent.

Regards

 

[rotrax]

I'm interested that you say that the LED lamp has affected the cut off between Red and green lenses on your bi-colour fixture. I presume that you replaced a single 25W incandescent lamp with a warm white 18SMD LED. If so I really can't see that, in practice, the visual output using the LED lamp would be any different from that of the incandescent.

Regards

Hi-if you read my first post on this thread (#13) you will see that I used a bicolour red/green,which lost a row of LED's and was quickly replaced by the supplier. With the temporary replacement warm white (12 LED's ) viewed from 350 yards away it was certainly bright enough for me. With the renewed 18 LED bicolour red/green it was even brighter. Brighter in fact than the incandesent. All purely subjective, just by taking a look from a distance that was estimated. With both LED bulb types there was a slight blurriness where the red/green lens joins at the very front. This was only apparent close to and is in reality of little significance. In my opinion, of course.

 

[noelex]

I'm interested that you say that the LED lamp has affected the cut off between Red and green lenses on your bi-colour fixture. I presume that you replaced a single 25W incandescent lamp with a warm white 18SMD LED. If so I really can't see that, in practice, the visual output using the LED lamp would be any different from that of the incandescent.

Regards

If you replace a filament globe with an LED "globe" that has a radius of 1.5cm.
If we assume 5cm from the centre of the filament to the edge of the navigation light the arc of illumination will change by about 15 degrees by my maths.
At the extremes of the cut off it will be less bright, but it is a change from the 112.5 degrees specified.