Flaming Flares

[Rigger Mortice]

Tells you nothing. The spectrum of the light emitted by the Odeo will be very different to that emitted by the pyro. The pyro will be bunging out a lot of Infrared and camera CCD's are often fairly sensitive to IR light. What's important is how notable the light is to the human eye, not a camera.

Undoubtedly true, but I think we can take it as read that a flare is going to be a lot brighter than an LED device. IIRC the YM report described it as being "100 times brighter". The scale of difference was obviously a subjective opinion but it is a bit naive to argue that the camera is not giving at least a fairly realistic impression.

 

[RAI]

I note that the flare needs a gloved hand and the laser does not. The latter is also not a fire hazard.

 

[Elemental]

Undoubtedly true, but I think we can take it as read that a flare is going to be a lot brighter than an LED device. IIRC the YM report described it as being "100 times brighter". The scale of difference was obviously a subjective opinion but it is a bit naive to argue that the camera is not giving at least a fairly realistic impression.

Undoubtedly true. But as I said

What's important is how notable the light is to the human eye

Brightness is only one component of that. If you've ever caught a flash of a laser led directly pointing at your eye (I know, I now ...) you'll know that it's a very attention grabbing stimulus. Like I said, I'll happily add it to my inventory, but it won't replace my pyros...

 

[maxi77]

I note that the flare needs a gloved hand and the laser does not. The latter is also not a fire hazard.

But it is potentially an eye hazard and often the damage is not obvious at the time. Just because it is not hot to hold does not mean it is not dangerous

 

[Bru]

As someone has already pointed out we're going round in circles now ... plus it's three days to offski and I've got a lot of getting ready to do ... so just a final point or two

EPIRB has a test function. And is kept in the cabin and battery changed periodically.

You could do the same with laser flares, but what about the ones packed into the liferaft?

How sure are you that pyro flares packed in the liferaft will function? Those you can't test. There's no reason why the liferaft packing can't be adapted to allow access to the eVDS equipment etc for user testing

When your eyesight is at risk there is a very big difference in flying towards an unknown laser light and flying towards a known device that has been properly cleared for the specific trial. Lasers can damage eyesight and a blind or visually impared pilot has no job, are you going to risk it? Many of the laser pointers you see on the market are potentially dangerous despite the markings on them. The variations in quality of cheap laser diodes can be consideable and though the batch average is safe individual units canbe significantly over spec.

Your STILL ignoring the FACT that Odeo eVDS equipment has been tested with UK SAR pilots. This is a non-problem that you're making up because of the word "laser" (and is indicative of the reasons why the word "laser" has now been dropped from the vocabulary of the manufacturers!)

As for the brightness, an eVDS does not need to be as bright as a pyro flare. It only needs to be bright enough to be seen

Right, stuff the discussions, it's nearly time to go do some real sailing!

All I ask is that if you see a feeble little flickering red light over there, please come and get me 'cos I is in trouble

 

[RAI]

But it is potentially an eye hazard and often the damage is not obvious at the time. Just because it is not hot to hold does not mean it is not dangerous

I believe the laser-flares uses lenses to spread the beam a little so that they just look like bright lights. Looking into either type of flare is not good for night vision.

 

[Rigger Mortice]

I wonder if there is any point in shining a laser beam (which is a parallel beam of light) through a lens to make it a diverging beam of light?

I must admit that I simply don't know the answer but I do wonder if it is the optical equivalent making ice cubes only to boil them to make tea.

 

[duncan99210]

Your STILL ignoring the FACT that Odeo eVDS equipment has been tested with UK SAR pilots. This is a non-problem that you're making up because of the word "laser" (and is indicative of the reasons why the word "laser" has now been dropped from the vocabulary

The only place I've seen this statement is on the manufacturers own website. I have not seen any independent academic report on the devices whatsoever. So until either the manufacturers get type approval for their device (ie it conforms to some internationally agreed standard) or there is an independent academic review of the effectiveness of the device versus conventional pyrotechnics, I feel that their claims are just that; claims.

Where is the report from the SAR pilots? Who commissioned it? Who reviewed it? Why isn't a link to it posted on the website? What methodology was used to determine the lack of damage to pilots eyesight?

 

[jerrytug]

Another point: if you let off a red hand held flare, the light is reflected and refracted by the smoke and the tiny bits of 'chaff', making it even more visible, especially at night. You don't get that with the battery operated imitations (unless something's gone seriously wrong).

 

[Bru]

I believe the laser-flares uses lenses to spread the beam a little so that they just look like bright lights. Looking into either type of flare is not good for night vision.

Nope, they don't. Because they don't actually use lasers

They use high power LEDs which became known (unfortunately) as laser LEDs but they are not true lasers

 

[RAI]

Here is a description.
http://www.practical-sailor.com/issues/37_33/chandlery/The-ODEO-Laser-Flare_11213-1.html
If the laser beams are to be seen from a wide range of angles above and below the plane of rotation, they need to be spread. If they use LEDs then the output is already spread.

 

[Bru]

Oh yeah?

and sixty seconds later ...



crudely photoshopped I know but I say again that the eVDS does not need to be AS bright as a pyro, it only needs to be bright ENOUGH. And it stays that bright for at least five hours

 

[Bru]

Here is a description.
http://www.practical-sailor.com/issues/37_33/chandlery/The-ODEO-Laser-Flare_11213-1.html
If the laser beams are to be seen from a wide range of angles above and below the plane of rotation, they need to be spread. If they use LEDs then the output is already spread.

From which I quote a critical passage which answers one of the misapprehensions about their use ...

"The ODEO uses U.S. Food and Drug Administration-approved laser light technology and meets EN 60825-1 and Class 3R regulations. This means that exposure won’t damage your eyes—but you still wouldn’t want to stare at the lasers. The ODEO is also safe to use during search-and-rescue operations because unlike laser-pointers, it won’t blind rescue vessel or aircraft operators."

 

[KellysEye]

>How sure are you that pyro flares packed in the liferaft will function?

Because they are replaced when the life raft is serviced which will be near the date the flares expire. That happened with our Avon life raft.

 

[Talulah]

>How sure are you that pyro flares packed in the liferaft will function?

Because they are replaced when the life raft is serviced which will be near the date the flares expire. That happened with our Avon life raft.

If LED flares came out before pyrotechnics the discussion would be the complete reverse. Why would you want something that has a potential to burn a hole in your liferaft instead of battery operated? "All is Lost" anyone?

 

[JumbleDuck]

Undoubtedly true. But as I said Brightness is only one component of that. If you've ever caught a flash of a laser led directly pointing at your eye (I know, I now ...) you'll know that it's a very attention grabbing stimulus.

That's why I'll take a short-lived whoomf! over a continuous flicker for now.

 

[JumbleDuck]

Your STILL ignoring the FACT that Odeo eVDS equipment has been tested with UK SAR pilots.

Sez' who, other than the manufacturer? Have the RAF published anything to say "Yes, they're not very bright and don't bother us"?

 

[JumbleDuck]

From which I quote a critical passage which answers one of the misapprehensions about their use ...

"The ODEO uses U.S. Food and Drug Administration-approved laser light technology

I thought you said they didn't use lasers?

 

[Bru]

Sez' who, other than the manufacturer? Have the RAF published anything to say "Yes, they're not very bright and don't bother us"?

Have they published anything to say "don't use these, we don't like them"? No. I'll therefore accept the manufacturer's statement at face value also taking into account that the MCA has advised that they are suitable as a secondary means of signalling (taking into account that they are not, yet, SOLAS approved)

I thought you said they didn't use lasers?

<sigh>

Strictly speaking they don't. Although that said we're getting into some very nerdy technical territory here. The Odeo Mk.1 and Mk.2 used 5 f a type of laser light emitting diodes (one of several solid state techniques are used to intensify the output of a P-N junction LED, you really don't want to know the details!). The Mk.3 uses 21 high intensity non-lasing LEDs.

High output LED technology has advanced in leaps and bounds over the last few years due to the growing demand for low power LED lighting solutions

Whether they are "laser" or "non-laser" is a bit of a moot point really. The advantage of using non-lasing LEDs is a wider beam angle. The drawback is having to use 21 LEDs instead of 5

 

[Rigger Mortice]

Strictly speaking they don't. Although that said we're getting into some very nerdy technical territory here. The Odeo Mk.1 and Mk.2 used 5 f a type of laser light emitting diodes (one of several solid state techniques are used to intensify the output of a P-N junction LED, you really don't want to know the details!). The Mk.3 uses 21 high intensity non-lasing LEDs.
..........
Whether they are "laser" or "non-laser" is a bit of a moot point really. The advantage of using non-lasing LEDs is a wider beam angle. The drawback is having to use 21 LEDs instead of 5

Where did you find that? I'm not questioning it. I'm genuinely interested, but have been able to find precious little technical info when I've looked.
I must admit that I was wondering if two or three CREE led's could be configured to good effect. I can well imagine that in a few years LED's will far out-perform flares in terms of light output.