The Problem with Laser Pointers is....

[Renato1]

..... as I discovered last night, yes people are very impressed with Jupiter, the Great Nebula, the Eta Carina nebula etc - but they seem to be even more impressed with the $5 laser pointer I was using to point out major stars and where those nebula were.
Cheers,
Renato

[CJ]

I had exactly the same experience last night with a mate of mine!

[gaa_ian]

Yep, I have done Dozens of obs nights with the Laser and the same is true !
It goes something like this : Look here is Saturn see the rings ....OK, but tell me about the laser pointer, can I get one ?
I have several and most are the $10 Bali variety (they work fine)
In the NT there were no specific laws against them.
How about in other states ?
Do you still have to show that you are a member of an Astronomy club to have one (IE: a legitimate reason for using one)

[glend]

The problem with laser pointers is they can ruin imaging. There is nothing more frustrating than to have some inconsiderate wave a laser pointer around your field of view when people are trying to do an imaging run. They have no place at star parties for exactly that reason.

[Renato1]

Yes, you now now the feeling. I'd heard of this happening with school kids, but was surprised with adults.
Cheers,
Renato

[Renato1]

No restriction on 1mW lasers, different restrictions on more powerful lasers in different states.
Cheers,
Renato

[doppler]

In QLD < 1 mw not restricted, < 10mw legal for firearm licence holders and < 20mw for profesional use and for members of a registered astonomical club / association for astronomy use. The max fine in QLD is 100 penalty points, which is $1000 + victims of crime levy, so a $35 a year club membership is good insurance if you want to use one in a public place.

Rick

[ZeroID]

Don't dare use them from my backyard. We're directly under the flight path 'handbrake turn' point for incoming flights from Australia. I have about 6-10 flights per night crossing overhead still pretty high up but you can hear the engine note change and first flaps go down as they start final descent and 180* turn for eastern approach.
I'd have every police chopper and probably the armed offenders squad round if I started using a laser pointer to find my way round the sky.

[Renato1]

Laser pointers are great for showing beginners what's where.
Are there that many beginners at Star Parties to actually warrant anyone using a laser to show them the basics?
Regards,
Renato

[Eden]

Can anyone provide any information on the legal restrictions for laser pointers in Vic and NSW? For example, max. allowed mW rating etc?

Cheers :thanx:

[Steffen]

For NSW: http://www.police.nsw.gov.au/services/firearms/laser_pointers

The salient part is the 5th paragraph, and the link contained therein.

Cheers
Steffen.

[doppler]

The beam from a laser is only about 1mm thick and is difficult to see from the side view after only a few meters so unless you actually target a plane they would not see it. Low powered lasers are useless with large groups as only those standing next to the source can see the beam.

[gaa_ian]

Thanks for the update rick.
That is useful as it is only the 5 to 20 mw lasers that are worthwhile really !
Cheers
Ian

[Eden]

Thanks for providing that useful link, Steffen.

It's interesting to note that they do not specify an upper limit to the power level, only that a permit is required for > 1mW (approved astronomical organization member excluded). However, I've heard anecdotal reports that it can be difficult getting anything > 5mW through customs.

I've never tried, but would like to purchase a pointer of reasonable power level for astronomy use. Any recommendations would be appreciated!

Cheers :thanx:

[barx1963]

My understanding is that green lasers over 1mW are prohibited imports without a licence, so if found in packages coming from overseas they can be seized and you can be prosecuted. It is a separate issue to the legality of their use, so even if you have a legitimate use, they can still be confiscated at the border.

Malcolm

[doppler]

If you want to want to bypass the legal red tape, it is legal in Australia to import laser parts, just not laser pointers over 1 mw. If you order the laser modules in one order and the housings in a completely separate order you will have no problems with customs. Once you assemble the parts you are governed by your state laws.

http://stores.ebay.com/Techhood

[creeksky]

Would one help attached to a finder scope for accuracy, or would a red dot finder scope suffice?
If I used one to the east it may be seen by aircraft coming into the Gold coast.
Though I am 80ks west of the aircraft.

[Jemmo]

Does anyone have a link as where to buy these green ones? I have a right angle sight and find it tricky to locate objects.

[barx1963]

Pete
I have used a laser, a telrad and a cheapo red dot finder and personally I find the red dot the easiest to use. Of course I am only using it to align on a bright star and then star hopping or setting up the 2 star alignment on an Argo Navis sytem (in that case I only have to use it at the very beginning of the night)
They are lightweight, work even when it gets cold (lasers often cease working when temp drop below about 5deg and so need to be connect up to dew heaters) the batteries last forever and are very easy to use.

Malcolm

[Allan_L]

I have had exactly the same experience, Malcolm. For me the perfect solution is the RDF to get in the general area, and then a right angled 9x50 finder (with cross hairs) to get spot on.



As there are (or were) little or no restrictions in Qld., I ordered a <20mw hand held from Sirius Optics. They also sell them set up as finders. >$100. (NOTE: not legal for general use in most states)
Edit: Quick check of their website indicates that these are no longer listed for sale here
also
<1mw from ebay for under $10 (apparently legal and just as good to use)

But please use responsibly.

NOTE: IISAC2014 Light Use Policy

[Renato1]

By the time you buy the bracket for the laser and the laser, it is getting dearer than a red dot finder. The red dot finder always works (after you use a blower to get dew off it), but the cheap lasers go very dim and stop working as they get very cold. Which would be very annoying when viewing on cold nights.

But they would be the laser finder would be fine this time of year.
Regards,
Renato

[cathalferris]

I worked out the brightness of a typical 532nm 5mw laser pointer at various distances, to satisfy my curiosity that they were not dangerous to planes past a certain distance due to beam dispersion.

It turns out, when I use my own 5mw Ebay special, that the beam dispersion is in the order of 1 metre per kilometre.

The illumination of the beam is about the same order of brightness as a car headlight at 1km. Because it's effectively a point source there are visible diffraction effects and the brightness will vary a lot very quickly (the exact same way a star would) making it something that attracts the attention.

Aircraft at cruise directly overhead are ~10 km distant, so the beam is ~10 metres in diameter and definitely not an issue for direct vision.

It gets less and less bright the farther away from the zenith the plane is. At 80km the pilot would have a pretty hard time seeing the laser and certainly would not be affected by the illumination.

Now, illumination of a hovering helicopter or a plane on approach is a completely different matter and certainly can cause a startle effect. But no physical damage would be possible from a <20mw laser out past a few hundred metres.

I don't like that pilots have to deal with the startling effects of a sudden laser illumination, but I dislike the overhyped response of the aviation community and authorities to the pointing of lasers at aircraft.

Regarding the use of lasers for pointing, if you can keep them above e.g. 10 C, they are great for being able to locate with one scope and use others to observe. I used an 80mm scope on a goto mount, with a hacked-together laser finder to sky-point while using another scope to observe the object in question. If you are any bit handy, a dewstrap along the pointer with insulation around the whole lot will keep the laser diode and batteries warm enough. I used little rechargable pocket warmers with the sodium acetate filling - worked a treat.