Laser pointer advice

[Tyr]

I've been asked to introduce some young minds to the night sky, either that or keep them busy for half an hour or so I'm not sure which.

When I had someone give me a guided tour of the night sky on holiday they used a laser pointer to show what they were talking about and what we were looking at which seemed to work well.

However there seem to be lots of very cheap laser pointers on amazon and I want to make sure I get something thats

* Visible as a pointer in the kind of summer semi dark we get in June / July.

* Safe to look at, by which I mean safe to look at when it's being pointed at the sky. I know pointing lasers into peoples eyes is never safe! Some of the comments on amazon talked about people getting permanent floating black spots in thier eyes after using some of the green ones

So many of the ones I'm seeing look like cheap and dangerous tat.

Some advice would be much appreciated

Tyr

[Slangers]

I got a green laser on amazon for about 12 quid. Think it was this one.

It does the job, no ill effects. Don't point at aircraft!!!

[nightvision]

I live near the coast and for small groups a 5mw green laser is enough.

If you live in an area with high humidity 5mw will usually be fine. For lower humidity, larger dispersed groups and or light pollution go for 10mw or higher to ensure the beam can be seen by everyone not standing close to you.

You want a green one like this:

7dayshop.com - Online Store

and for more power:

Green Laser Pointers, Green Laser, Smart Laser Pointers on sale (231grid)

[trickytree]

I can't advise on the actual pointers, but I know Cool Gadgets at the Right Price - Worldwide Free Shipping - DealExtreme do them, and I've ordered hundreds of pounds worth of stuff from them in the past and they are quick and reliable. You could pick yourself a couple up at their prices!!

cheers

[Tyr]

Thanks for the responses and links all, interesting to hear what power output other people are using.

Tyr

[Skiddins]

Might want to see if you can get an LED version, certainly would be safer than a proper laser, particularly if 'small hands' accidentally get hold of it.

[Tyr]

In the end I ordered one from a well known telescope retailer, which was a little bit more expensive than amazon. It arrived yesterday and feels quite solid, and has a push on release off switch so it will turn off if dropped. It's says it's <5mw on the outside and that it's a class IIIa rated device.

Having tried it out last night briefly being careful not to point it in the direction of any aircraft, it was a just visible beam in the late evening sky. I'm near the flight path for heathrow I think, so it's not something I'm going to be using at home.

Will need to be careful re small hands getting hold if it, fortunately they're not that small. I think a quick talk about not pointing these things at people/cars/aircraft will be worth while, although I don't plan on passing the pointer around.

Now I'm just hoping that after weeks and weeks of cloud that there will be something to point at!

Tyr

[ollypenrice]

I use them for introductions, too, and they are incredibly effective tools in the main. With children, though, the danger is that they find the laser more interesting than the sky!

Olly