[ATMoB-discuss] 55mw green laser pointer oh my
George Roberts
gr at gr5.org
Wed Jun 7 17:38:24 CEST 2006
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
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