What laser pointer is best ?

[ninja2]

Hello again IIS...

I was watching "Stargazing Live" on ABC tonight and reminded of the value of a good laser pointer in astronomy.

I'm in process of rejoining ASSA and so I'm aware of the laws about lasers > 1mW and safety guidelines, but I need some guidance about what brands, power and features are best, and typical cost. As an example ... how powerful was that laser brandished in the "Stargazing Live" show? It ws impressive, but maybe it's more than I need?

thanks in advance

[gaseous]

Hi Chris, I bought a generic green laser off eBay last year for about $20. Listed as <1kw, the delivered product had <5kw on the sticker so it may be more powerful than strictly allowed, depending on where you live. It's a great device. Mine has a removable rechargeable battery that I had to buy separately from Battery World for another $20 or so, but for $40 it does the trick, similar to that shown in the show last night.

[sil]

no difference between brands etc. no features beyond on or off. Green laser is all you need to look for. The one Greg was using on the show you are ignoring the fact it was humid there so LOTS of moisture in the air for the photons to bounce off (light itself IS invisible after all) plus as they demonstrated you were watching them through a low light camera that amplified the effect, its not that bright in person. Plus of course they are not toys and of course can be see miles away so if you're in a suburban area the police can see where the laser line is pointed from.

[Malcolm]

Not too many of these work well in cold weather. Mine is scope mounted and the solution was to wrap it in a USB powered heater pad run by a phone battery charger. I think I paid around $6 on eBay.

[DavidTrap]

I just looked into a 20mW version from a "reputable" supplier vs eBay - roughly $300 shipped.

My 1mW ebay one is rather dim and unusable in the city, but definitely visible under dark skies.

I agree that the one being used on Stargazing Live was either a high powered one or definitely amplified by the fancy camera they were using - maybe a bit of both.

DT

[ninja2]

Thanks all ... pretty straight forward then.

Although @gaseous .... 5kW for $20? :eyepop: hmmmm, great price but not sure I need that much oomph!

[sil]

Nothing to do with "one of those". Batteries dont work well in cold temperature.

[issdaol]

$300 is quite expensive for a 20mW laser pointer !

A deeper look around should give some better priced options from other reputable suppliers.

[glend]

All laser pointer are bad, especially for imagers. If you have ever had some well meaning idiot 'accidently' wave a laser past the front of your scope while your observing you will know why they are dangerous. It was bad to see a so-called expert using a laser pointer during the ABC Stargazing Live show last night, when someone was observing right through the light path.
They can only be justified as a knowledge sharing device, when at a dark site and no one is at a scope or imaging.
And of course, in any sort of urban environment they will have the police knocking at your door.

[gaseous]

This is the bad boy here. Listed as <1kw but maybe they need the sticker to say <5kw in case it's actually 1.1kw or something. They come with an end piece that produces a sparkly multi-dotted effect, so you need to unscrew this end piece to get the single beam, which is maybe how they get away with selling it as more than 1kw. I wouldn't say it's a lot of oomph, but it certainly does the job, and as others have said, you won't make many friends at a star party if you start waving it in front of people trying to image/observe.

http://www.ebay.com.au/itm/Green-Laser-Pointer-Pen-1mw-532nm-with-Clip-Visible-Beam-High-Power-NY-009-/391474418380?hash=item5b25b192cc

[ninja2]

@gaseous, that "looks" like a suitable device
now I'm sure you meant mW not kW ... a factor of 1,000,000 difference there !

[issdaol]

Thats a bit like saying All 4WD's are bad because a few people don't pay attention or know how to drive/handle a 4WD compared to a small sedan :lol:

Pointers have a purpose and in the hands of a responsible person paying proper attention they are perfectly fine :)

[gaseous]

Yep, my bad!

[ninja2]

Is a 1mW laser simply not powerful enuf to be visible from a distance and so doesn't attract police attention, but a 5mW is easily visible from a distance? Or is this only true if the conditions are right (e.g. humidity).

(only curious ... not planning to test police response unit)

[LewisM]

The guy observing in the background was merely a "prop" - he was not really observing per se. I suppose they should have turned the lighting off too so he could "observe".

Lasers, guns, cars, knifes, sticks...ban 'em all cause they are dangerous

[doppler]

Side on, a laser beam is only visible for maybe 50 meters because the beam is only a couple of mm wide (we've done a few school viewing nights across the road from the police station without being noticed), however the beam can travel for many kilometers so is very visible at a distance if pointed directly at you.

[doppler]

You can get those rechargeable batteries on ebay from Australian warehouses for a couple of $ each. The good thing about buying lasers from Australian ebay suppilers is that they have already passed though customs.

[dannat]

they were using some kind of IR camera -they did a demo with a normal camera & it was nearly pitch black

[LewisM]

Without watching it again, they did say turning off the lights before they showed how dark it was, so i don't any i.r used at all. IR is usually b&w.

[Stardrifter_WA]

I use an Arctic Fox weapon sight laser. I mostly use it for initial set up and when not in use I just put it in my jacket pocket to keep it warm on cold nights. I can't be bothered having to wrap in a heater and have one more thing to plug in. It is fitted to a normal finder dovetail riser block.

Cheers Pete

[sil]

want a bet? especially at night when the police helicopters are out with flir cameras sweeping for hotspots of dope growers or you're a block away from a major road where a patrol car is waiting for a break from boredom or a commercial flightpath is overhead. No you arent likely to blind a pilot from the ground but with the focusing effect of corrective glasses and refraction of windows you cant say its impossible. Certainly a momentary distraction is all it takes for a driver or pilot to cause an accident.

I know lasers are cool , but its rare to hear anyone responsible enough to handle one safely, its no wonder the clamp down in the laws. its just something to be so flippant about, in faster than a blink a person can permanently lose their eyesight.

Greg on the show firstly didnt have pointers like light sabres, they arent that bright in person, any just because they arent as visible they do have a lot of energy. Just like most uv torches only emit a tiny part of the uv spectrum (longwave uv and violet/blue visible light) but the other end of uv is the opposite (shortwave uv?) which is invisible to the eye but packs a ton of energy that can cause damage, this is the stuff you slip slop slap to avoid. If you paid attention you'd notice Greg raised raised the pointers skywards before turning them on, kept them on for the minimal time required, turned them off before lowering and immediately slid them face down into his pocket. Under the circumstances it was pretty much the best way to use them without them becoming the center of attention, they were never pointed towards people and no one was moving around (I guess everyone there was roped off behind the cameras)

sorry but as someone with a newly acquired permanent disability joviality on something as potentially dangerous as this is disappointing and somewhat offensive. People are going to do stupid things regardless and regret it later on but please dont give that impression here where we have young members. set a good example.

[Stardrifter_WA]

Lasers are not bad. They are like any tool, if used correctly they are safe. If some fool is waving it around you just need to educated them. I have had to educate others on the safe use of lasers. Everyone has the right to use their equipment at a star party, without exception, in my view.

For me, due to a severe neck injury, a laser is a vital part of my kit, but it is usually only used for initial alignment.

[Menno]

Hi There,
The following NSW Police webpage and the link referred to in the 3rd last paragraph may shed some light on the use and licencing requirements for green laser pointer in NSW....

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

Hope this helps

[skysurfer]

5 KILOwatts ???
Would you like to cut steel I beams ?

[gaseous]

Yes, I've already had my error pointed out to me, thanks. It would still be nice to have the steel beam cutting option in the toolbox though.

[ninja2]

So I now have a laser pointer, 532nm < 1mW. Even at this "low" power it's ability to point out a star is most impressive. Although it was a warm night with some humidity last night, so it will be intereresting to see how well it performs on a cold clear winter's night.



That NSW police info says just having any laser in your custody is an offence in NSW unless you have a good reason.

The ASSA Guidelines for Lasers (https://www.assa.org.au/media/16425/laserguidelines.pdf) quotes from SA legislation. Reading that literally suggests the legislation ignores lasers <1mW (see "Clause 10A of Schedule 2" on last page). This implies simple possession of a laser <1mW by anyone is not an offence in SA.

So is this a point of difference between the law in NSW vs SA?

(armchair lawyers may respond here :))

[doppler]

It's all in the wording, "good reason". Astronomy is a good reason. It's a bit like having a knife in your car if you say its for fishing or cutting rope etc that's ok, but if you say it's for self defense you have to go and see the judge because that's illegal possession.

[Kunama]

In NSW the following advice is given on the NSW Police website:
" Note that you will not need to obtain a permit to possess/use a laser pointer with a power level greater than one milliwatt if you are a member of an approved astronomical organisation. "

Note also that in some states the Act refers to 'hand held' laser pointers. Thus one would argue a pointer permanently mounted on a telescope does not fall within the restrictions.
Some states have blanket bans on Class3B and 4 lasers.

[ninja2]

Let me be more specific

I'm a current member of ASSA. For South Australia only: if I want to show a friend how well my new <1mW laser works for pointing out a star, and I'm careful not to point at planes or cars etc, could I still attract SA Police trouble for simply using a laser?

As an aside I got my multimeter out and measured the volts and current feeding the laser. When the laser is active volts drop to 2.65 and current is 270mA - so about 0.7mW. Its impressive such little power generates so much useful green light, and only $12 :)

[gaseous]

From the Qld Police website.

[Robair]

The various guidelines seem relatively clear. Have a valid reason to be using your laser and stay under the approved power limit.
However is that still potentially a hazard for aircraft?
I have a triple whammy whereby I live under the north inbound lane of entry for GA into Bankstown, the west inbound lane for MED1's into Westmead Hospital, and what appears to be a regular training area for Polair.
I feel I could follow all the rules and still cause problems?
I'm thinking that speaking directly to Polair or Careflight may be the go?
Thoughts?

Rob B

[Hemlock]

Hello all;

I am a biology teacher and amateur astronomer. I often take students on overnight field-trips, and find that this is a great opportunity to do a stargazing talk. As anyone who has ever tried to point out a constellation or a star to a novice audience on such occasions can attest, a powerful laser pointer is absolutely invaluable for such work.

I am in desperate need of some good, reliable advice as to how to go about acquiring a relatively higher-powered laser pointer in Australia. I say "higher powered", because I have already purchased a 1 mW from a reputable Australian supplier, and unfortunately I have discovered that such a unit is just not powerful enough to point out stars on a clear, cold night sky in a rural location (they do better in the suburbs, which I guess is a reflection of the greater levels of air pollution). I know from experience that a more powerful laser pointer (in the possession of an acquaintance visiting from the States) did act very effectively as a star pointer in the same clear-sky, rural locations where my 1 mW unit failed.

I've looked into the legal side of things, and essentially, here in Queensland, laser pointers up to 20 mW are legal IF they are used for a valid astronomical purpose and are in the possession of someone who is the member of a recognized astronomical society. Obviously, I understand that common sense considerations apply in terms of never pointing a powerful laser pointer at anything other than a distant star of planet.

I was hoping someone on your forum could suggest a "reputable dealer" to purchase such a laser pointer from? Surely there must be some sort of recognized astronomical supplier within Australia who can handle such goods? Some of the general listings on eBay seem pretty psychotic (pictures of lasers being used to ignite match heads and that kind of thing) and the last thing I want to do is buy a dangerous unit or support an irresponsible seller. I would imagine that any such purchase from overseas would be blocked by customs anyway?

I've been trying to navigate this issue for months now, without success. There must be some way of buying a laser pointer in a responsible way and from a responsible seller? Any suggestions would be greatly appreciated - especially in regards to how much mW power is needed to be effective as a star pointer, and how much power is just needlessly dangerous. Has anyone had a positive experience in ordering one of these online? cheers, John.

[Tinderboxsky]

John, have you checked out the Telescopes and Astronomy website? The firm is in Adelaide and have been selling a range of laser pointers for many years. Matthew Lovell, who owns the business, is very helpful. Steve

[sil]

Hemlock, there is simply no such thing as a safe laser, even many torches can cause blindness. Responsible? try arguing that point with a cop or parent of someone whose child was blinded because of a distraction or child pulled on your arm while you were using it. If you are a biology teacher than you already know scientific instrument suppliers to purchase from, those may be close to the actual stated wattage value, otherwise just buy any piece of crap like most people. If you understood anything about photons then you'd know a laser is invisible and its dust/water vapour and other particles in the air that you are seeing the photons reflected off and 1mW is more than enough for that. Surely as a teacher you know how to answer your own question accurately instead of online forums.

[Hemlock]

Can I offer a huge thanks to forum-poster Steve for helpfully pointing me in the direction of a legal and reputable source for laser pointers in Australia.

For other people in my position who might require such an instrument for teaching purposes, At the time of writing, they are available from a South Australian firm, "Telescopes and Astronomy". Here is their web site;

http://www.telescopes-astronomy.com.au/telescopes_contacts.html#

They are not cheap, but you have the assurance of buying an Australian made product that is properly rated in terms of its engineering and power output. This is a far better option than some of the highly dubious laser products available on e-bay, and in any case regardless of your State legislation, it is illegal under federal law to import these devices at the kind of power output you would need for astronomical purposes. A reminder to potential buyers of laser pointers to check your State legislation in regard to these devices to be sure that you are operating within the law. Needless to say, like any technology that could be hazardous if misused - such as 3D printers, knives, cold and flu tablets, fertiliser and automobiles - they should be handled with the utmost respect for safety at all times.

Sil, your reply to my original post was unnecessarily aggressive and uncivil, and I have reported your comment to the site moderators.