[ATMoB-discuss] 55mw green laser pointer oh my

[Tinkler, James B (CSC) (US SSA)]

I bought a 25mw green laser from Howie Glatter
(http://www.skypointer.net/) a few years ago and have been very happy
with it.  I have labeled it as "Not for use by children" and will not
even let adults I do not know well use it.  The "light saber" factor of
it being so "cool" just makes it to dangerous.  I have never had a
problem with people being able to see it at this level of brightness.
It is, as you said, a great teaching tool.  My advice with green lasers
with power outputs over 5mw is to treat them like weapons.  Be very
careful who gets to touch it and how it is used.  Never let anyone
without prior instruction use it.

-Bruce Tinkler

-----Original Message-----
From: atmob-discuss-bounces at atmob.org
[mailto:atmob-discuss-bounces at atmob.org] On Behalf Of George Roberts
Sent: Wednesday, June 07, 2006 11:38 AM
To: atmob-discuss at atmob.org
Subject: [ATMoB-discuss] 55mw green laser pointer oh my

Because of discussion on this email list I decided to purchase a <5mw
green laser pointer for use at star parties to point out stars 
and satellites in the sky.  Green is supposedly 6 times brighter to the
eye than a red laser pointer of the same wattage.  Well it 
worked for me but was difficult to see.  Soon I learned that people more
than 2 feet away could barely see it and by 3 feet away it 
was hopeless.  I was never able to use it successfully with more than
one person at a time and I stopped using it.

BUT ALL THAT HAS CHANGED !!!!

I bought and received a 55mw green laser.  It is much more dangerous to
the eye and it is recommended that you wear goggles if you 
point it anywhere near reflective surfaces which are in every direction
indoors.  But man is it bright!  When it is dark enough to 
still read you can already see the beam.  When it is fully dark in
Wellesley (mag 3 limiting magnitude) you can see the beam clearly 
100 feet away and you can see which star it is pointed to within a
degree or less.  I wouldn't want to get any brighter than 55mw. 
It is just a fantastic tool for pointing out objects in the sky.  Many
times I have spotted a mag 3 satellite and most of the kids 
around me can't find it.  The satellite is usually gone before the last
10% of the kids get a chance to see it.  This is *not* 
suitable as a laser pointer indoors - it is just too bright and too
dangerous.  Also you need to look for aircraft before turning it 
on each time.

The laser fits in the same tiny package as the 5mw laser - the size of a
large pen.  It takes 2 AAA batteries and I have only used 
it with rechargable Nimh which are of a lower voltage and thus probably
lower power than alkaline batteries.  The lasers only seem 
to be available from one place (according to many people who have
looked) and they are $210.  They have much more powerful lasers 
but I think that the next one up, 75mw, would be too bright and I
suspect you could get away with 35mw (the next model down) just 
fine.

I got mine at:
http://wickedlasers.com/

- George Roberts
http://gr5.org