Re: pocket lasers for star pointing?

Chris L Peterson <clp@xxxxxxxxxxxxxxxxxx> wrote in
news:i8nfb3t085eamg1gmtameds44tq6u39fhs@xxxxxxx:

On Tue, 07 Aug 2007 01:06:10 -0000, Skywise <into@xxxxxxxxxxxxxxxxxxxx>
wrote:

Speaking for US law...

A "laser pointer" must be less than 5 mW.

But a "laser pointer" can be legally modified to output more than 5mW,
as long as it is properly labeled (doesn't still carry its class 3a
sticker).

Sure, you can modify it all you want. But don't sell it or use
it in public or you're breaking the law.



Cheap laser pointers CAN leak sufficient levels of IR light to be
an eye hazard.

I don't think this can easily happen- especially with the cheapest
models. I know of no case of it actually happening.

It can and does. There are many pointer modders out there who
actually remove the IR blocking filters, or due to the cheap
design, when it's modded it emits more IR. This has been
verified by those who have laser power meters buying a pointer
claimed to be 50mW and finding it's maybe 10 to 15mW of green
and several tens of mW or leaking IR. Under these circumstances
a power meter calibrated for green will indicate and erroneous
high power reading due to the leaking IR. It's a known scam
amongst us laser hobbyists.


Even a legal laser of low power can be dangerous. Even if no
actual physical damage is caused, the dazzle effect can be
quite dangerous, especially to the night adapted eye in a dark
place - such as an aircraft flying at night.

The airplane example is a crock. There's no way a 5mW laser is capable
of dazzling a pilot flying at any reasonable altitude. Of course, if you
stand on the end of a runway you might be able to manage it, but that's
not a realistic scenario.

I dare you to try it.

The only caveat is the difficulty of actually hitting the pilot
in the eye. But if you manage to do it, it's certainly going to
be dazzling.

At any rate, it's not a good idea to try.

One last thing, I am specifically talking about dazzling one's
vision, not causing any sort of damage.


I see those same ads in the astro mags and certain ones I have
written in complaints regarding them numerous times because the
products they are selling ARE illegal. Period.

How so? Are they being sold as class 3a devices? I'm not doubting you,
just wondering what criteria you see which makes some legal and some
illegal.

A laser point has a simple on/off switch. This is allowed for
devices under 5mW of power. Above that, if the laser device is
being used in a public setting, as opposed to a controlled lab,
or incorporated in another device that prevents exposure, the
laser is required to have a minimal power on delay, an emission
indicator (laser on light), and a key switch for safety.

A modded laser pointer does not have these.

There are some folks out there who are making "hand held lasers"
which have these safety features, but there are also other laws
which some of these manufacturers are skipping out on. As a
manufacturer, they are required to maintain certain paperwork
and make certain reports to the CDRH.

Oh, and modding a laser pointer for resale purposes technically
makes you a manufacturer.

I've been an active laser hobbyist for at least 10 years. I've
got some knowledge of these things, either learned on my own or
passed on by laser show professionals in the biz for decades. A
few did tours with some great bands going back to the 70's.

But please don't just take my word for it. Here's some reference
material for you, all on the FDA's web site.

"Important Information for Laser Pointer Manufacturers"
http://www.fda.gov/cdrh/radhealth/products/lpm.html

"Illuminating Facts About Laser Pointers"
http://www.fda.gov/fdac/features/2005/305_laser.html

"IMPORT ALERT #95-04"
http://www.fda.gov/ora/fiars/ora_import_ia9504.html

And finally, the legal code regarding lasers,
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?FR=
1040.10

If you want to learn more about lasers, there's the alt.lasers
newsgroup. A massive source of information is the LaserFAQ, to
which I have made very minor contributions. This can be found at
http://www.repairfaq.org/sam/lasersam.htm

Brian
--
http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism
Seismic FAQ: http://www.skywise711.com/SeismicFAQ/SeismicFAQ.html
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Sed quis custodiet ipsos Custodes?
.

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