[geeks] laser for pointing out stars

[Barry Keeney]

On Tue, 2 Sep 2008, Francois Dion wrote:

> I need a green laser pointer for pointing stars so that a group of
> people can quickly identify which I'm talking about. Years ago there
> was a 5mw restriction on pointers. And I think that a portable laser >
> 5mw had to have a keyswitch and a dongle and autoshutoff. Is this
> still the case? I know that 5mw with a green laser is usually enough,
> but I've heard from many people that 10 mw is probably more useful.

  I do astronomy as a hobby and I use two 5mw green lasers for the 
star parties my local club runs. One is mounted on my telescope, the 
other I hold to point out stuff.

  The scope mounted one comes in handy to show people where the telescope 
is pointed and to find stuff. I made my telescope and it doesn't have
any computer/tracking system to find objects, I star hop to find stuff.

  The 5mw should be fine most of the time. If the sky is clear, calm, 
and dry it might be a bit hard to see the laser but that will be true
no matter the power of the laser. Got to have stuff for laser to
bounce off of to see the beam. 

  I got mine from http://www.z-bolt.com/ after I dropped the one I
got from another company about 18 inchs and it stopped working.
I've dropped the ones I got from z-bolt a few times and they
are still going strong. 

  One important thing! Green lasers can do major damage to the
eyes. Eyes are sensitive to green light and a 5mw green laser 
can cause blindness so higher powered lasers will do more 
damage/faster. 

Barry Keeney
Chaos Consulting
email barryk&at&chaoscon.com

"Rap is Square Dancing gone terribly, terribly Wrong...."