Laser pointer

[Second Time Around]

I'm looking for a laser pointer that I can both use as a pointer when visitors arrive, plus as a finder.

However, I'm looking for one that turns off if I let go of a switch.

Any suggestions please?

[johninderby]

Most laser pointers have a button that needs holding down to keep them on. Some  use a little ring that you have to position over the button to keep them on continually.

Useful little article here.

https://starlust.org/astronomy-laser-pointers/

Edited March 20, 2021 by johninderby

[Louis D]

I have green laser sights permanently mounted to each of my scopes or alt-az mounts or permanently attached to a Synta/Vixen finder foot.  They have built in alignment screws and come with a momentary switch on a coiled cord as well as a push button toggle switch.  They also come with either a 1 inch diameter barrel mount or a Picatinny rail mount.  For permanent mounting, I affix a short Picatinny rail to the scope (think Dobsonian).

Here's the sight I've been using.  They're pretty cheap from ebay China if you're willing to wait a few weeks.  You'll also need to order the proper rechargeable lithium ion batteries and charger.  I prefer the longer battery version (18650) of these sights because the battery lasts longer on cold nights than the shorter 16340 version.  The longer version only became available in the last couple of years.  The sight is longer, but I think it's worth it.

Just buy a regular green laser pointer separately for outreach.  You don't want to be faffing about trying to realign the laser sight each time you dismount/remount it.  They hold alignment really well once set.

Edited March 22, 2021 by Louis D

[johninderby]

Just be aware that the laws on the use of laser pointers are far tougher in the UK than they are in the US. If you live within 15 miles of an airport don’t use one at all. 

They used to be popular here in the UK years ago but now they seem to have fallen oit of favour. 

[Louis D]

At least here in the US, the only recent arrests have generally been of rednecks stupid enough to lase a police helicopter.  Hello, they have night vision cameras on them that can easily pinpoint your location.

[johninderby]

Use common sense and you will be fine.

Yes you have to be pretty dumb to point a laser at the police. 🙄

https://www.laserpointersafety.com/sentences/files/tag-uk.html

Edited March 21, 2021 by johninderby

[Second Time Around]

Thanks guys, no wonder I couldn't see anything suitable from UK astro retailers.

[Zermelo]

On 21/03/2021 at 00:32, johninderby said:

Just be aware that the laws on the use of laser pointers are far tougher in the UK than they are in the US. If you live within 15 miles of an airport don’t use one at all. 

They used to be popular here in the UK years ago but now they seem to have fallen oit of favour. 

In particular, the one linked to above says <5mW, and the UK limit is 1mW. And some chinese models have been known to output way over the stated value.
Also, it's one of the 532nm versions, so internally it will be an IR laser with a pump diode frequency doubler. These can be fine, if they have an effective filter to chop out any remaining IR (the amount of unconverted IR increases as temperature decreases and the diode efficiency drops). If not, there is a risk of retinal damage if accidentally exposed. The 520nm versions are a different design, and don't have this drawback (and are better in the cold). But of course, more expensive.

[Second Time Around]

Thanks, Zermelo.

[Louis D]

19 minutes ago, Zermelo said:

In particular, the one linked to above says <5mW, and the UK limit is 1mW. And some chinese models have been known to output way over the stated value.

I have no doubt those ebay laser sights are way over 5mW.  They tend to be brighter than pen lasers.  That, and they burn through large lithium ion batteries.  It does make them easier to follow into the sky, though.  All that and the unfiltered IR is why I won't use them at outreach events.  They're just too dangerous for casual use.

[AlexK]

Just shop for the cheapest offer of a 2xAAA-driven laser pointer on Amazon. The price there is on par with what you can find for the same on eBay and Ali or even better as they have a huge local stock usually. Been shopping not so long ago for a friend for the exact same application. He is 300% happy with the below "kit":

https://www.amazon.com/Quoiron-Purple-Kitten-Interactive-Sticks/dp/B08R7CDBLF

I'd get all 3 colors as each works for different light pollution / eyes darkness adaptation situation. Or at least to see what works best for you. Also great if several folks are pointing into the sky simultaneously (like one is asking, you answering).

The quality of that model is totally reliable after all these years they are made in China. I have 3 like these (2 of them for over a decade) and all still working great. I have that same one Louis D is recommending, no difference in the performance, but the gunsight one is quite bulky and heavy and definitely much harder to remove from its holder or operate in the hand with the rail clamp on it.

For the cold weather just stick with the "Lithium" alkalines (e.g. Energizer). They are great in cold weather and very lightweight. Lasting like forever in these pointers. In fact, the laser diode will fail in the deep cold first. So if planning to expose it for long time you need some $100 model with the special cold resistant diode or/and the separate diode module heater circuit. With the above pointer you can just quickly remove it from the holder on the OTA and warm up in your pocket in just few minutes.

For mounting as a finder, don't overdo it as some folks do with 6 collimation screws following the optical finder two rings mount 🤦‍♂️. That's a weird overkill as the accuracy of pointing with the GLP is around 1/2 degrees at best anyway. So a trivial friction hole block fastened on the side of the OTA for easy pointer removal when needed for the night show is totally adequate. On my Astroscan I'm using a trivial pair of ropes holding it in the corner (click the image for some more details):

The beam is always in the center of the scope FOV when ON.

Edited March 26, 2021 by AlexK

[nfotis]

Had ordered a laser pointer via Ebay, but it doesn't operate when I installed fresh batteries in it (I suppose that a 5 USD price was too good to be true...).

This looks exactly like these: https://www.amazon.com/3Pcs-Interactive-Cat-Kitten-Dogs/dp/B09228WSL8/ref=sr_1_1

 

Any suggestions? I am thinking about outreach mostly (to show constellations etc to others)

N.F.

 

Edited October 19, 2021 by nfotis

[Louis D]

1. Make sure the batteries are inserted the correct direction.
2. Try another battery, especially one known to be working in another device.
3. Do not use rechargeable batteries.  They only put out 1.2V.  You need 1.5V for these.
4. Screw and unscrew the battery holder section while holding down the button.  Sometimes, slightly loose works best.
5. Try scraping the contacts with a jewelers screwdriver.  Tarnish may have built up in storage or transport.
6. Shim the battery compartment with a card stock sleeve to better center the battery.  The positive contact on these can be troublesome.

[ONIKKINEN]

1 hour ago, nfotis said:

Had ordered a laser pointer via Ebay, but it doesn't operate when I installed fresh batteries in it (I suppose that a 5 USD price was too good to be true...).

This looks exactly like these: https://www.amazon.com/3Pcs-Interactive-Cat-Kitten-Dogs/dp/B09228WSL8/ref=sr_1_1

 

Any suggestions? I am thinking about outreach mostly (to show constellations etc to others)

N.F.

 

Cheap laser pointers like this are an extreme eye-hazard, be VERY careful when using laser pointers from sketchy sources!

 

Very often these no-brand chinese lasers are nowhere near their rated safe(ish) power of 1-5mW and instead can be in the 50-100mW range. These are built to such a low price that there is probably no quality assurance of any kind. A typical 5mW laser pointer is still dangerous, mind you but not the instant irreparable eye-damage levels of the more powerful ones. Not a thing i would personally want to save any money on.

[Richard N]

I corresponded recently with the CAA on this very topic. I live about 6 miles from Manchester Airport and enquired about using a laser pointer. To cut a long story short, they asked me to submit the information to their NOTAMs system. I did this and no NOTAM was issued because the airspace regulator did not consider it necessary. I also contacted the flight safety section of Manchester Airport to ask if they had any specific recommendations for safe use: they never replied. This was just my case with my specifics so it may well not apply to you but from my perspective I now have a email trail that could be shown if the Police knock on the door. Nothing you do removes your duty of care to aircraft of course. Care is essential but there is clearly no blanket ban or 15 mile limit as others have suggested.

"I am an amateur astronomer and I would like to use a laser star finder on my telescope. Laser pointers are often used to point out stars. The laser that I have is green and 1mW output.

By way of background, the following may be of use. 

I only observe on clear nights (rare here) so maybe 10-20 times per year. Typically during the course of two hours of observation, the laser would be used about 10 times. Each time it would be on for about 2 seconds while the telescope is aligned on a specific star. I would listen and look for aircraft before each use. I have two locations where I might use it:

1:  NGR SJ xxxxxx (Macclesfield)
2:  NGR SJ xxxxxx (Over Alderley)

I have contacted the CAA and filled in their notification form to cover a period of a few months. In reality this will be quite a rare event. I would be grateful for any specific guidance that you can give me in relation to Manchester Airport."

Edited October 21, 2021 by Richard N

[Zermelo]

1 hour ago, Richard N said:

Nothing you do removes your duty of care to aircraft of course.

I think that's the important point.
On the one hand there's nothing to prevent you from using them per se, but on the other hand if you do (even accidentally) cause an incident then an offence has been committed, however careful you were being and whatever you did to check with authorities beforehand.

[Cosmic Geoff]

Legislation and attitudes clearly differ in the UK vs. USA.  Helicopters regularly fly over my location and I occassionally see a police helicopter hovering around.  Personally I see no need to use these laser pointers on the night sky and any amateur astronomer who gets his/her collar felt by the police is not likely to get much sympathy from me.

[Louis D]

3 hours ago, Cosmic Geoff said:

Personally I see no need to use these laser pointers on the night sky

Just wait until your neck and back are so stiff with injuries, age, and arthritis that you can't bend around properly to use a unit power finder (RDF/QuikFinder/Telrad/Sighting along tube/etc.).  A green laser sight has been a game changer for me.

[Tiny Clanger]

A few years ago  (it must be, I was at someone else's house for no particularly pressing reason...) I was in a room where the TV was on, sound down low , I zoned out from the uninteresting gossip around me about neighbours, and gave my attention to one of those real life UK police & security camera TV prog.s , a very dreary (and cheap) way to fill the bit between adverts. A police helicopter was following some miscreant or other at night, watching with the night vision camera, and as it flew slowly over a built up area some half wit sat outside at a BBQ pointed a laser at it. 

The half wit in question apparently didn't understand that as well as pointing at the 'copter , his little beam was also pinpointing himself, at the other end of it,  and the airborne observer directed one of the police cars to exactly where he was, and gave the cops a description of his clothing so he could be extracted from the crowd of happy party goers and arrested.

Idiots like that make outdoor, upward directed  laser use seem like a really bad thing to normalise .

[Louis D]

47 minutes ago, Tiny Clanger said:

A police helicopter was following some miscreant or other at night, watching with the night vision camera, and as it flew slowly over a built up area some half wit sat outside at a BBQ pointed a laser at it. 

The half wit in question apparently didn't understand that as well as pointing at the 'copter , his little beam was also pinpointing himself, at the other end of it,  and the airborne observer directed one of the police cars to exactly where he was, and gave the cops a description of his clothing so he could be extracted from the crowd of happy party goers and arrested.

As Ron White pointed out, "You can't fix stupid".

[Guest]

A late entry to this old thread.  I just picked up a Z Bolt extreme weather laser.  Good down to 14 degrees.  It is a green laser and I also ordered the extended wired switch for it.  The switch replaces the end cap of the laser and as long as I hold the button down the laser is on.  Let go and it goes off.  I have to say it is way easier to see then the red laser 

[bosun21]

I unfortunately have a local airport approximately 10 miles from me. That rules out laser finders for me.

[AstroKeith]

Be aware that in some countries, UK and Europe for instance. It is now technically illegal to use a 5mW laser 'pointer'.

They shouldn't be imported and sold as 'pointers' (yet they still are!)

Owning one is OK, but the regulatory health bodies have declare them unsafe for use by the public. 1mW is the maximum.

Many institutions (ie universities) have responded by banning their staff from using them, or requiring training and risk assessments.

[StarryEyed]

I miss my laser pointer. But I found star hopping more entertaining and the journey more rewarding. 

[iapa]

don't get why anyone needs a laser pointer

Prepared to be bombarded