Astronomy Laser

[bomberbaz]

I know there are lots of rules/regulations with lasers, and rightly so. 

However I am considering getting a laser for one of my setups. I remember seeing one which was legal put to great use in scotland at a darksite and was wondering if it was feasible to replicate.

Anybody tried this already?

Edited April 20, 2021 by bomberbaz

[Louis D]

I just use green laser sights purchased from China via ebay.  They're mounted on Picatinny rails or barrel mounts.  They come with momentary switches on a coiled cord making them really easy to use and not forget to turn off.

Unless you make a deliberate effort to lase aircraft, you should be fine legally.  It's people lasing police helicopters and landing planes that ruin their use for everyone else.  I just listen for aircraft and do a quick check of the skies before lighting up to stay out of trouble.

[AlexK]

You haven't explained what you plan to use it for and why. :)))) 

So I assume as some arbitrary visual telescope pointing aid, because you have a sore neck preventing you from using an RDF, Telrad, or an optical finder (a typical reason stated :)))).

At a real dark site (which you have mentioned), I would recommend skipping "gun" laser sights with the bright green beam (which Louis has recommended above). They will blind you just from looking at the beam in the sky at night enough to drop your telescope an inch or two in aperture when observing DSOs. Get a red or blue (violet) pointer instead. Also keep in mind that you can ruin the work of any astrophotographers near you with it.

Edited April 21, 2021 by AlexK

[Louis D]

1 hour ago, AlexK said:

You haven't explained what you plan to use it for and why. :)))) 

So I assume as some arbitrary visual telescope pointing aid, because you have a sore neck preventing you from using an RDF, Telrad, or an optical finder (a typical reason stated :)))).

At a real dark site (which you have mentioned), I would recommend skipping "gun" laser sights with the bright green beam (which Louis has recommended above). They will blind you just from looking at the beam in the sky at night enough to drop your telescope an inch or two in aperture when observing DSOs. Get a red or blue (violet) pointer instead. Also keep in mind that you can ruin the work of any astrophotographers near you with it.

In my suburban skies, I can't even make out my red and violet laser pointers' beams in the sky.  They're just too dim.

[michael8554]

There are 8 British Standard classes of lasers, and roughly speaking anything over 1mW is considered a hazard to eyesight.

I doubt any Chinese manufacturer is bothering about those guidelines.

Michael

[iapa]

11 minutes ago, michael8554 said:

There are 8 British Standard classes of lasers, and roughly speaking anything over 1mW is considered a hazard to eyesight.

I doubt any Chinese manufacturer is bothering about those guidelines.

Michael

Link to the details is below.

As an aside, your Howie Glatter collimation is 5mW so comes under the Class 3R - for use in workshops.

Hotech’s collimation laser output is <1mW making it a class 2.

 

https://www.gov.uk/government/publications/laser-radiation-safety-advice/laser-radiation-safety-advice

 

[iapa]

13 hours ago, bomberbaz said:

I know there are lots of rules/regulations with lasers, and rightly so. 

However I am considering getting a laser for one of my setups. I remember seeing one which was legal put to great use in scotland at a darksite and was wondering if it was feasible to replicate.

Anybody tried this already?

No, but, per my earlier post, the guidelines indicate you should ensure you have a properly labelled device no more than Class 2; as this can be safely used in an unsupervised area.

These people seem to be largest supplier in UK, or claim to be.

Edited April 21, 2021 by iapa

[Zermelo]

13 hours ago, Louis D said:

Unless you make a deliberate effort to lase aircraft, you should be fine legally.

Louis, that may be the case in the US, but over here it is a strict liability offence, i.e. the authorities have only to identify the perpetrator, not to prove malicious intent. For UK readers, there is some discussion of the legislation here.

Also see this recent thread.

They are great gadgets I'm sure, but you do need to be careful what you buy, and where and how you use them.

[Louis D]

1 hour ago, Zermelo said:

Louis, that may be the case in the US, but over here it is a strict liability offence, i.e. the authorities have only to identify the perpetrator, not to prove malicious intent.

So the mere act of owning or taking delivery of a >1mW laser is an offense under this statute?  The mere act of pointing a laser to the sky is an immediate offense?  How many people were arrested for having those Christmas laser light shows missing the side of the house and pointing into the sky?  I read of a lady in New Jersey who was issued a warning when hers got knocked over backward and was lasing nearby planes.

Edited April 21, 2021 by Louis D

[Zermelo]

16 minutes ago, Louis D said:

So the mere act of owning or taking delivery of a >1mW laser is an offense under this statute?

I haven't gone back to the actual legislation Louis, but the link I posted above says "So not illegal to own a >1mW portable but should not be used as a pointer. There is a slight gap in the criteria allowing <5mW to be used for general pointing based on this statement." and while possession itself appears not to be illegal, "... some police officers can still arrest and/or confiscate the device under their discretion if they believe it is justified." One of the problems is that many lasers claiming to be <1mW are actually (much) more powerful, but the ordinary user doesn't have the ability to test.

The website is referring both to the law and to guidelines that don't have any specific legal status, but might be relevant to any prosection (this is also what has happened with our COVID legislation, leading to some confusion). IMHO one of the problems with a lot of legislation in the UK is that it is too vague. We seem to prefer "flexibility", and leave it to courts to "interpret".

[Louis D]

Those star shower laser shows may be using as much as 100mW lasers and have been causing issues here in the US.  Are they even sold in the UK given that laser pointer law?

[Zermelo]

I don't know, but the marketplaces are hard to police completely. We have trading standards people who try to spot and take down ads, but it's a bit whack-a-mole.

[pipnina]

Is it possible to get products that perform a similar job to laser pointers? Maybe narrow-beamed and very bright torches? Wouldn't be a perfect solution and might be dependent on RH% but there might be torches bright enough to do it?

[Alien 13]

1 minute ago, pipnina said:

Is it possible to get products that perform a similar job to laser pointers? Maybe narrow-beamed and very bright torches? Wouldn't be a perfect solution and might be dependent on RH% but there might be torches bright enough to do it?

Funny thing about torches is that you can get some that are worse than a 100mW laser, setting fires etc at a distance etc..

Alan

[shropshire lad]

I use a 1mw laser for polar alignment but only switch it on when I'm close to polaris ....... but I check the skies before I switch it on and listen out for any aircraft or helicopters .

It's only on for a couple of seconds.

[Zermelo]

25 minutes ago, pipnina said:

Is it possible to get products that perform a similar job to laser pointers? Maybe narrow-beamed and very bright torches? Wouldn't be a perfect solution and might be dependent on RH% but there might be torches bright enough to do it?

Possibly, but I think they'd need to be excessively bright.  The point of the green laser is that the light is strongly scattered away from the direction of the beam, meaning that you can see the actual beam from different angles. Most laser wavelengths don't do that, which is why with them you can see only the "spot" if it illuminates an object (and obviously no good for astro purposes).

[wulfrun]

3 minutes ago, Zermelo said:

Possibly, but I think they'd need to be excessively bright.  The point of the green laser is that the light is strongly scattered away from the direction of the beam, meaning that you can see the actual beam from different angles. Most laser wavelengths don't do that, which is why with them you can see only the "spot" if it illuminates an object (and obviously no good for astro purposes).

Also a major factor that the green lasers are close to the human eye's peak sensitivity wavelength. Red and blue/violet are in a far less sensitive part of the spectrum, as well as the scattering issue. Red lasers are highly visible in mist and fog (rather unsuited to astro then, of course!).

[wulfrun]

36 minutes ago, pipnina said:

Is it possible to get products that perform a similar job to laser pointers? Maybe narrow-beamed and very bright torches? Wouldn't be a perfect solution and might be dependent on RH% but there might be torches bright enough to do it?

You'd need a vast amount of power to replicate a laser. The beam is so intense because it's so narrow. Try looking at 1mW-worth of an LED's output, it's not impressive at all. You can't focus non-laser light in the same way, it's just not possible due to physics. Also, the inverse-square law applies to "normal" light, meaning the beam would be relatively short. Besides, if you could replicate it you'd have the same concerns about pointing it skywards.

[wulfrun]

(Double post, accidentally, ignore)

Edited April 21, 2021 by wulfrun

[wulfrun]

2 hours ago, Louis D said:

So the mere act of owning or taking delivery of a >1mW laser is an offense under this statute?  The mere act of pointing a laser to the sky is an immediate offense?  How many people were arrested for having those Christmas laser light shows missing the side of the house and pointing into the sky?  I read of a lady in New Jersey who was issued a warning when hers got knocked over backward and was lasing nearby planes.

Not so fast, this is the UK! Some of our laws aren't straightforward. There are things you can own legally but not buy legally, things you can buy legally but can't be sold legally and a lot of wierd variations. I think lasers (pointer type) over 1mW fall into "legal to own but not use without good reason" category, although I'm no expert. Pointing any GLP skywards and being noticed tends to invoke the "arrest and ask questions later" response from the Police, best avoided.

Edited April 21, 2021 by wulfrun
clarity

[Alien 13]

I expect its all about wavelength, it used to be fine to have a 5mW green laser and indeed they are completely "eye safe" but they do cause a blink reaction...strange that motorists are bombarded by 5mW lasers all the time with no ill effects. It does pose a problem for those of us who may or may not have bought 5W ex tank lasers from "exchange and mart" in the 70s.

Alan

[AlexK]

15 hours ago, Louis D said:

In my suburban skies, I can't even make out my red and violet laser pointers' beams in the sky.  They're just too dim.

That only means you are not well dark adapted. I'm in direct view of San Francisco and Oakland, but I can see my super-cheap red and blue pens' beams just fine when looking from the spot closer to the source, so I can regulate how much it blinds me by simply moving my head around it.

[bomberbaz]

Thaniks for all the comments people.

A little more digging as brought up this Emax green laser pointer | Emax Laser Pointers

One of these could be used to mount it 35mm Stand Mount for Green Laser Pointer, a Helper of Astro Telescope Black | eBay

However I have seen them fired directly into a 10x50 finder to shine a beam into the sky. It is this option I am considering for my travel outfit

[Cosmic Geoff]

I manage to use my astro equipment without using a laser, so anyone in the UK who uses one and gets his collar felt by the police will get no sympathy from me at all.

[Zermelo]

16 hours ago, bomberbaz said:

A little more digging as brought up this Emax green laser pointer | Emax Laser Pointers

Please be careful. That's a 532nm device (like the majority on sale) and they can be dangerous (especially when cold) if not properly constructed.
"Direct" green lasers operating at 515/520nm are inherently safer (but you won't find one for £20).

https://www.cloudynights.com/topic/484640-green-laser-pointer-in-cold-be-careful/

https://skyandtelescope.org/astronomy-news/observing-news/green-lasers-a-hidden-danger/

https://www.sciencedaily.com/releases/2010/08/100804110207.htm

https://spie.org/news/3328-the-dangerous-dark-companion-of-bright-green-lasers?SSO=1

(any references to permitted power outputs probably relate to US, not UK, rules)

Edited April 23, 2021 by Zermelo
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