Outreach Laser Pointer

[PhotoGav]

Wasn't sure which forum to post this question in, but hopefully this one will work!

Please can somebody recommend me a good laser pointer for astronomy outreach sessions. I have one (an internet special), which is good, when it works, bu it is incredibly unreliable, which is unimpressive when swashbuckling in front of an audience!!

I look forward to hearing what you experienced light sabre wielders suggest.

Thanks,

Gav.

[JOC]

I'm not a fan of these, they are getting very bad press in the UK because they are causing problems for aircraft pilots.  I would say manage without one.

[laowhoo]

I'd like to see the clippings of said present continuous claims. We live directly under an airline route for two major airports, and in a state which has had  specific municipalities ban them for specific abuse,  but unless and until there comes some such broad danger as you allege they're still legal, even here. Evidently amateur astronomers have the sense to know how to use them, and the general public isn't as awful as you think. We use them for outreach too, OP, but be prepared--even certain soccer mom members of our Princeton group gave the old eyebrow at our use, b/c they're superior, no doubt, or live in trepidation of boogeymen. Probably both. I'd recommend ours but you want duty-free.

[Buzzard75]

I use Z-bolt Galaxy series. They have three models, Ruby (red), Emerald (green) and Sapphire (blue). The red isn't good for much other than indoor, classroom, or presentation work. The green and blue however, are extremely bright and visible at night. These are not cheap laser pointer though. They are very powerful with an extremely long range and could legitimately blind someone.

As JOC said, lasers can be dangerous for pilots and you must use extreme caution with these. If I even see a plane, I won't use it until it's passed. If I see members of the public using their own pointers at our events, I recommend they not or at least be mindful of where they're pointing and that they under no circumstances let their children use them at our events.

[PhotoGav]

Thank you for your comments so far.

I am fully aware that laser pointers can be dangerous when used inappropriately. I am a responsible adult that can restrain from pointing the beam at passing aircraft, etc! As Buzzard75 says, if there’s a plane about, just wait for it to pass.

A laser pointer is insanely helpful when you are trying to point out asterisms, constellations and the location of DSOs to a group of people, especially when they are beginners. Just saying “you see that bright star up there and the other bright star to its left and down a bit” is completely pointless! Try it!

I look forward to hearing some more laser pointer recommendations. 

[Cosmic Geoff]

TBH I think that laser pointers are to be deprecated. We don't want to be associated in the public mind with the idiots who point them at pilots. It only needs one incident for us to be tarred with the same brush.

[PhotoGav]

Using one safely presents a great opportunity to educate and alert people to the dangers, especially to youngsters, who often make up the outreach groups that I am involved with.

[Handy_Andy]

Rother Valley optics has a 5mW green laser for about £30. I find that these pointers tend to drain batteries even when not being used, just something to be aware of.

[tuckstar]

The cold is your main enemy. I have one that is supposed to be 200mw, but doubt that it is. It uses a lithium ion 18650 battery, the same as I use in my ecigs. It is quite powerful and is alot better/ brighter than the 5mw I used to use. I did buy a heater for the 5mw with a long cable so can just be plugged in to my dew controller but never really used it as I got the other one which is much bigger. This one still sufferers the same problem even though when I put the battery in the charger it reads full.

[PhotoGav]

13 minutes ago, Handy_Andy said:

Rother Valley optics has a 5mW green laser for about £30. I find that these pointers tend to drain batteries even when not being used, just something to be aware of.

Thanks Andy - I think that is possible similar to the one I currently have, which is not as reliable as I would like!

4 minutes ago, tuckstar said:

The cold is your main enemy. I have one that is supposed to be 200mw, but doubt that it is. It uses a lithium ion 18650 battery, the same as I use in my ecigs. It is quite powerful and is alot better/ brighter than the 5mw I used to use. I did buy a heater for the 5mw with a long cable so can just be plugged in to my dew controller but never really used it as I got the other one which is much bigger. This one still sufferers the same problem even though when I put the battery in the charger it reads full.

T* - that is probably exactly it, the cold. Perhaps a 'pointer-glove' is required. I have a session at the local school tonight and will give that a go! What is the 200mw one that you refer to - do you have a link to it available online somewhere, please?

[Nyctimene]

Do some research on: "green laser 520 nm" or "Direct Green Laser"; or have a look here:

https://infiniter.com/quarton-laser-module/green-laser-module/direct-green-laser-module/

and here:

http://www.everyonetobuy.com/520nm-green-laser-pointer-light-pen.html

The usual green laser pointers operate on 532 nm wavelength, and are, as tuckstar pointed out, very sensitive against cold. The newer 520 nm technology seems to be much more cold-resistant. I've got no experience with these; perhaps some US-american stargazers may contribute with their experiences.

57 minutes ago, PhotoGav said:

A laser pointer is insanely helpful when you are trying to point out asterisms, constellations and the location of DSOs to a group of people, especially when they are beginners. Just saying “you see that bright star up there and the other bright star to its left and down a bit” is completely pointless! Try it

Exactly!

Stephan

[tuckstar]

Got mine from wish.com.

 https://www.wish.com/m/c/56c572abf5041c1774c56ee0.

The heater I got was from ww astro. I could be persuaded to sell you my heater if you want one.

[PhotoGav]

Thank you Stephan and Tuckstar. Interesting about the cold and wavelength.

[Louis D]

I'll add that just because you're an adult doesn't mean you'll use green laser pointers responsibly.  I've seen grown adult professionals at star parties flailing laser pointers about in the dark like light sabers in the sky.  I have to scold them for setting a bad example for the kids around the field.  Kids learn by example and will point a laser point right at someone instead of in the sky because they don't understand the blinding dangers associated with them.

[VIctor_M]

Maybe you will not point any plane intentionally, but you could still do it accidentally. Other point is that if you are going to be outside with other astronomers and there is someone doing astro-photography, you can easily ruin their session

[Nyctimene]

On 5.2.2018 at 15:26, PhotoGav said:

Using one safely presents a great opportunity to educate and alert people to the dangers, especially to youngsters, who often make up the outreach groups that I am involved with.

+1 for that. I'm using the green laser pointer only as a final confirmation of a star hop routine, that I've explained extensively before, just for a few seconds. You want the public to marvel the stars, and not the light saber.

Some good hints can be found here:

http://www.laserpointersafety.com/tips/tips.html

An old Latin saying is "Abusus non tollit usum"; which translates: "Abuse does not suspend/override the right way of use".

A lot of truth in this, IMO

Stephan

[Luna-tic]

On ‎2‎/‎7‎/‎2018 at 13:40, VIctor_M said:

Maybe you will not point any plane intentionally, but you could still do it accidentally.

I don't buy into that; pointing a laser is like aiming a gun, be sure of your target before pressing the trigger. I've yet to see a star or nebula with a green and red wingtip light or flashing strobe. The US FAA is not very forgiving of "accidents" when it comes to pointing a laser at an aircraft, so it's best to take a look around at outreach or other stargazing events and make sure there's nothing around before using a laser pointer. I agree with Photogav that educating the public about them is important . Our observatory is directly below a pattern entry point at the edge of Class B airspace for a major international airport, so for us at outreach events (every other Friday night), it's a constant thing for us to watch out for.

The pointer I use is an Orion Skyline Deluxe. It's 5 mW, takes two AAA alkaline batteries. Comes in a nice padded metal case and has a pocket clip. Green is most visible to the eye and shows up well against a dark sky. It's $50 USD on their website.

[George 47]

I use a green laser pointer at outreach events and find it incredibly useful.

Of course taking sensible precautions avoids problems and I have produced a risk assessment for any organisation/schools that asks me for one. My laser is limited to 1mW. It may not be ideal for sunset star gazing but it still shows bright stars. At 5mW the blink response protects damage to eyes, at 1mW it is far more effective. Anything more powerful than 5mW could cause issues (and why would you want one)?

I minimise the amount of time it is on to just pointing out the stars. If there is a plane nearby then I do not use it. The stars are fixed so any planes that go near the laser will quickly go past, even if I miss they are there. The laser has a key that turns off the laser. Yes it is easy to bypass it but it is there to stop accidents or drain the battery. No one uses it but me especially any excited youngsters.

And yes if youngsters ask about getting one I refer them to their parents/teachers.

Last night it was easy to highlight Betelguese, Rigel, M42 and the Pleiades in a few seconds and be sure that everyone saw it. When I did not use a laser there was always someone who had not seen the object. As always be sensible.

[PhotoGav]

Thank you George. Which particular pointer do you use? I am on the search as the one I have seems to fail in the cold, which isn’t much good for astronomy! How does yours fare in the cold winter nights? Do you notice any deterioration in performance?

[Luna-tic]

Main reason they quit working in the cold is the batteries. As the batteries cool, voltage drops and the laser is sensitive to the lower voltage. I keep mine either wrapped in my hand or in a pocket inside my jacket. Fresh batteries in the cold also help.

5mW is the most powerful you can find for consumer use. No reason to need more unless you're trying to burn something. We have medical grade lasers at work (surgery), in several types; CO2 and Holmium, and they have outputs up to 10W. You can punch a hole in a tongue depressor in less than a second with the CO2 version.

[PeterW]

I’d buy a specific Astro one from an Astro retailer, you may pay a little more, but the output is likely to be what you expect. I recently bought a “spare” green laser from a cheap online supplier and specifically selected a “5mW” one:.. looked a “bit bright” when it came.. measured it at work and it was indeed somewhat more than I wanted or needed. I’ve added a neutral density filter to the end to bring it down to the required level. 

Pointers are a very powerful tool for outreach, helping other find stuff and to help you locate stuff quickly. like any potentially dangerous tool (eg knives) you need to be aware of the risks and be safe and educate others when you use one, pass on the good practice. I live near a “quite large” airport and use one without trouble... look for the moving lights, listen out and wait till the sky is clear before you fire it up and then only for as long as you need. Keeping it warm is also necessary as they will dim rapidly if they get cold.

Be safe

PEterW

[George 47]

7 hours ago, PhotoGav said:

Thank you George. Which particular pointer do you use? I am on the search as the one I have seems to fail in the cold, which isn’t much good for astronomy! How does yours fare in the cold winter nights? Do you notice any deterioration in performance?

It is an amorphous Chinese laser from e-bay but I do try to take care of the battery by keeping the laser in my pocket or wrapped in my hand. I always have a charged spare in my jacket pocket with the terminal protected. No problems so far.  

[Juan from Madrid]

On 2/7/2018 at 19:40, VIctor_M said:

Maybe you will not point any plane intentionally, but you could still do it accidentally. Other point is that if you are going to be outside with other astronomers and there is someone doing astro-photography, you can easily ruin their session

I wonder the time a green laser pointed to the sky from ground may impact the eye of a plane pilot that is flying at 900 km/h, the laser orientation required to do so, and the intensity with which it eventually arrives, when the laser owner is not deliberately pointing to the plane.

Not that I have the answers, just curious.

 

[RT65CB-SWL]

I have seen cockpit videos of high altitude aircraft being the target of green laser by an idiot / or idiots at ground level. It is very scary viewing. 

[Nyctimene]

Scary as well are the statistics of laser-aircraft incidents, about 20 per day as reported by the FAA, and rising:

http://www.laserpointersafety.com/latest-stats/latest-stats.html

Fortunately, the percentage of permanent eye damage seems to be low. But, one or two minutes of blindness of the pilots, approaching a major airport, may cause much more harm.

Stephan