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laser pens

Posted: Mon Jan 23, 2012 12:16 pm
by snowdon
Can anyone please advise on a good quality (and UK supplier) laser pen for pointing out stars etc. I do a lot of youth group work and this item would be a great advantage when showing the sky to groups. I have seen some relatively cheap (less than £10) on amazon but generally all state that the batteries are eaten and that the pen's beam does not last long. I saw one used on the Stargazing Live programme and thgought it was a good tool. Thanks

Posted: Mon Jan 23, 2012 8:26 pm
by dualyn
Hi Snowdon,
you could try widescreen centre,they sell a good variety of Astro gear.

Regards Duane.

Posted: Mon Jan 23, 2012 8:34 pm
by dualyn
Hi Snowdon,
just me again,when you get one of these laser pens,to avoid the batteries going flat fairly quick keep it in your hand or in your coat pocket that way your natural body heat will help to keep the batteries working longer.
On the whole i find mine to be a great educational aide.

Duane(Dualyn)

Posted: Mon Jan 23, 2012 8:49 pm
by David Frydman
I don't like the idea of laser pens at all, because of misuse and dangers.
But if you are getting one and it uses AA or AAA batteries, lithium disposable batteries work well in cold temperatures and last perhaps 6x longer than Alkalines, perhaps longer in the cold. I don't know if they are recommended for laser pens.
I use Lithium AAs in Canon IS binoculars and they last ages.

regards, David

Posted: Mon Jan 23, 2012 10:00 pm
by snowdon
Thanks Gents for your comments. I hadn't heard of the Widescreen Centre, but I have looked on their site now, thanks Dualyn.

Posted: Mon Jan 23, 2012 10:07 pm
by dazcaz
I have just bought a dual laser "pen" from Maplin. Both red and green lasers for 25 quid.
http://www.maplin.co.uk/dual-green-and- ... ter-340845

It seems to be of decent quality and the green laser is as bright as my old green laser pointer that cost me almost double a few years back.

There is nothing wrong with laser pointers as long as they are used sensibly. It's the muppets who point them at aircraft etc that give us genuine users a bad name.

They make great "finders"
I mount mine on my 'scope and align it as I would a finder scope. This makes targeting the 'scope so much easier. You point the bright line at the target rather than try and find it through the finder scope. This can kill the batteries though. So I only turn it on when I am near the target.

Posted: Mon Jan 23, 2012 10:50 pm
by The Bat
I bought mine from here: http://www.digitaldaffodil.co.uk/

It's so handy for public star parties. I used it for the first time for our Stargazing Live event, but I did hold it the whole time, partly to make sure it didn't fall into the wrong hands and partly to keep it warm. For added safety I also take the batteries out when I am done using it to prevent the button getting pushed by accident when it's in my accessory box. The case that came with it even has room to store the batteries in when not needed.

Rachel

Posted: Tue Jan 24, 2012 11:05 am
by brian livesey
I'd take issue with David about Lithium batteries being okay in the cold. I've tried them. It's been my experience that, in low temperatures, the diode beam wilts regardless of the type of batteries used.
The only way round this seems to be to buy an expense ORION green laser-pen from the USA. These don't seem to be temperature-sensitive in Winter.
The problem seems to be finding a US supplier that exports them to the UK.

Posted: Wed Jan 25, 2012 8:04 am
by Gregger

Posted: Wed Jan 25, 2012 10:46 am
by brian livesey
We should mention that a cheap laser-pen will keep going in cold conditions if a dew heating strip is wrapped round the diode end.

Posted: Wed Jan 25, 2012 3:19 pm
by snowdon
Thanks all for your replies. I have done some looking around on the sites mentioned, and thanks to Dazcaz - I didn't think of Maplins just round the corner from me. I have tried a couple out in their shop - they were very obliging and let me try them out in the dark under the counter, and I settled on the 2 colour option pen which worked fine in the garden last night! Thanks everyone.

Posted: Wed Jan 25, 2012 8:14 pm
by dazcaz
The two colour one is cheaper than the single colour green one :)
I bought he dual colour even though I doubt I'll ever use the red :)

Posted: Thu Jan 26, 2012 10:37 am
by Gregger
brian livesey wrote:if a dew heating strip is wrapped round the diode end.
Silly question, but which is the diode end, the bit tip where the light exits I guess?

Posted: Thu Jan 26, 2012 10:40 am
by Gregger
Oh and there's this

http://www.altairastro.com/product.php? ... 243&page=1

Although makes mounting testy

Posted: Mon Feb 13, 2012 10:05 am
by brian livesey
There's another way to keep a laser-pen finder warm without the need for a heating strip.
Some skywatchers keep the pen warm in a pocket when not being used, then, point the pen through the finder to home in on the target object.
Problem solved. :D