Lasers?

[dherbman]

Nothing wrong with a headmistress who has a mirror in her ceiling.

 

[JeffG]

Nothing wrong with a headmistress who has a mirror in her ceiling.

Thats definitely DIR.

 

[Rick Inman]

Nothing wrong with a headmistress who has a mirror in her ceiling.

Hey! A small mirror on the ceiling to reflect the laser. Good idea! We'll be able to shoot that thing in all sorts of places and no one will ever know from whence it came.

 

[radinator]

Sorry, to clarify. If a laser is powerful enough to do damage it is classified as 3b, the laser pointers that are sold as laser pointers must be 3a or lower. As I recall the EU regulations are even more restrictive than the US regulations on this aspect. they have a seperate 3r designation for laser pointers, and additional rules. And yes I know the regulations, the ANSI book is on my self. I work in laser research and have been trained as a laser safety officer under OSHA standards.

Don't count on it. The lasers sold as laster pointers are *supposed* to be 3a or lower, but I have seen several gas station/truck stops selling higher rated ones as laster pointers. The laser safety officer where I worked would find these regularly and bring them in as examples on how regulations don't protect you, responsibility does.

 

[dherbman]

Thats definitely DIR.

LOL.....still

 

[Xanthro]

Couple of problems.

One in very clear water you wouldn't have much of a light column, to trace back to your buddy. Simply seeing a dot doesn't tell you where your buddy is located.

Two, most lasers are red and red is still the weakest and most easily absorbed color. You simply wouldn't get to see very much of it. Let's say you and your buddy are 15 feet off the bottom, that means the light has traveled 30 feet by the time your buddy sees it, 15 feet from you to bottom 15 feet from bottom to your buddy. There isn't going to be much red left after that.

 

[cdiver2]

Yeah... it would really only be useful on recreational dives with good ambient lighting. A can light is definately better for the job.

Yeah... if I try it out and it doesn't actually work worth a $#&* under water, that would be an excellent reason not to use it. If that's the case, I'll be glad mine (also made for diving) only cost $15 used.

for attracting fish into an area to photograph, They think its edible

 

[Cacia]

I bought mine for Fish ID and quickly got sidetracked.

ahh..yes, of course, the red gets filtered out! wish i'd come up with that.

 

[MSilvia]

One in very clear water you wouldn't have much of a light column, to trace back to your buddy. Simply seeing a dot doesn't tell you where your buddy is located.

That could be a problem, except for several points.
First, I almost never dive in very clear water... probably less than 5% of my dives have vis over 40 feet.

Second, the dot isn't intended to be used to locate a teammate, only to let you know that they are aware of your location, still with you, and okay. You should know where your teammates are without the help of the dot... it's just there to keep you from having to look over your shoulder to know they aren't having problems.

Two, most lasers are red and red is still the weakest and most easily absorbed color. You simply wouldn't get to see very much of it.

That's absolutely a big shortcoming. If the laser doesn't penetrate well enough to be effective, it won't work. No doubt about that, but since most diving around here requires close proximity to teammates and whatever you hope to look at, it might be good enough. Around here, I'm generally no further than 10' from a surface of some sort, and often within a foot or two.

You're right though, that a laser probably wouldn't be a good general-purpose tool for those reasons, even if it might be effective in the conditions in which I'm most likely to use it.

Let's say you and your buddy are 15 feet off the bottom

In most cases, we wouldn't be able to see the bottom from 15 feet, much less a small red dot on it.

 

[Halthron]

As mentioned, red will be filtered out fairly quickly but if you really want one, you can buy green and blue lasers which will go further.

You may not lose your salvation for "helping people to read" but installing a mirror so they don't catch you might be pushing it