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For Pointing Out Things Above to Others...

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#1 NinePlanets

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Posted 16 February 2024 - 12:35 PM

In response to a recent locked discussion:

 

Back in the OLD, OLD days when my hair was a different color, we used FLASHLIGHTS with incandescent bulbs and D-cells to point out stars and constellations to groups of other folks.

 

Lasers did not exist yet.

 

Guess what? Flashlights still work!


Edited by NinePlanets, 16 February 2024 - 12:35 PM.

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#2 gstrumol

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Posted 16 February 2024 - 12:43 PM

There was a post earlier that discussed the use of flashlights as pointers. Somewhere ...



#3 drt3d

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Posted 16 February 2024 - 01:22 PM

Maybe but not as well as lasers.


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#4 Sincos

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Posted 16 February 2024 - 01:23 PM

Yeah that discussion ended up getting locked , cuz too many of us kept returning to use of lasers instead of flashlights . Would like to hear from the user who spoke of investigating these ,    https://www.batteryj...lashlight-guide
Seemed like a good idea but no further info .



#5 BFaucett

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Posted 16 February 2024 - 01:39 PM

Yeah that discussion ended up getting locked , cuz too many of us kept returning to use of lasers instead of flashlights . ...<snip>...

 
It wasn't locked because of the discussion of lasers. It was locked because of the discussion of lasers over 5mW which is not allowed by the CN Terms of Service.
 

III. Practicing Safe Astronomy

b. Members may not discuss or post links to sites that discuss, advertise, or sell laser pointers and modules that are greater than 5mW.

https://www.cloudyni...tion=boardrules

 
Cheers! Bob F. smile.gif

 


Edited by BFaucett, 16 February 2024 - 01:47 PM.

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#6 Tony Flanders

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Posted 16 February 2024 - 03:24 PM

Flashlights with highly focused beams work pretty well, but lasers work a lot better, and put less light into the sky as well.

#7 David Knisely

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Posted 16 February 2024 - 04:04 PM

In response to a recent locked discussion:

 

Back in the OLD, OLD days when my hair was a different color, we used FLASHLIGHTS with incandescent bulbs and D-cells to point out stars and constellations to groups of other folks.

 

Lasers did not exist yet.

 

Guess what? Flashlights still work!

Yes, the big 2 or 3 "D" cell Maglights put out a nice collimated bright beam that is visible over a wide area when doing larger group constellation talks.  You do have to shield the front end a bit (maybe with one of those plastic orange translucent cone shields used for directing traffic or with just an empty paper towel roll), but they do work well and aren't killed by low temperatures like some green lasers are.  However, at major star parties, white-light flashlights are a definite "no-no".  Clear skies to you.


Edited by David Knisely, 16 February 2024 - 09:06 PM.

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#8 Phil Cowell

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Posted 16 February 2024 - 04:14 PM

Show folks the target on Sky Safari. It orientates to the sky. Doesn’t mess up folks imaging either.


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#9 TayM57

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Posted 16 February 2024 - 10:17 PM

Show folks the target on Sky Safari. It orientates to the sky. Doesn’t mess up folks imaging either.

That ruins night adaption though. Looking at a screen makes it more difficult to see the fainter stars in the sky when switching from the screen to the sky.

 

I have a green laser, but rarely use it. I don't use it like a telrad- it's used for outreach and pointing out specific stars/constellations. That's it.


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#10 sevenofnine

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Posted 16 February 2024 - 10:25 PM

If you're having cold weather issues with your pen light GLP try these:

 

https://www.amazon.c...,aps,535&sr=8-5.


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#11 Tony Flanders

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Posted 17 February 2024 - 05:22 AM

If you're having cold weather issues with your pen light GLP try these:
 
https://www.amazon.c...,aps,535&sr=8-5.


In 99% of all cases the problem is with the laser itself -- or rather the phase-shifter that turns the beam green -- rather than the batteries.

I've never had much of a problem as long as I keep the laser warm in my pants pocket before I start to use it.


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#12 NinePlanets

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Posted 17 February 2024 - 09:24 AM

Yes, lasers DO work much better than flashlights for pointing at things. In fact, I use one of much higher output level than we are allowed to discuss here. I was merely pointing out, for those who object to the things, that there are alternatives for them.



#13 sevenofnine

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Posted 17 February 2024 - 11:28 AM

To test the effectiveness of Energizer Ultimate Lithium batteries non-rechargeable batteries, I put the Orion Skyline Deluxe laser pointer in the refrigerator for several hours then tried it on the night sky. It worked fine with a strong green beam of light. It's important to not confuse these lithium batteries with the rechargeable ones. The non's are 1.5v and the recharge's are 1.2v. It makes a difference borg.gif



#14 Jon Isaacs

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Posted 17 February 2024 - 11:39 AM

Yes, lasers DO work much better than flashlights for pointing at things. In fact, I use one of much higher output level than we are allowed to discuss here. I was merely pointing out, for those who object to the things, that there are alternatives for them.

 

You just discussed using a laser with a higher output than 5mw.  This is not a question of objecting to using lasers that are greater than 5mw, it is about practicing safe astronomy. 

 

Have you ever been trained in laser safety?  

 

For what it's worth, I sent a mod alert. 

 

One reason I don't use a laser pointer is that there are people out there who do not understand the safety issues who are using them in unsafe ways.  When someone is using a green laser, anyone around them should be concerned that it might be an unsafe laser.  I was trained in laser safety and had yearly training updates.  It's just not worth risking people's vision, yours or someone else's.

 

Jon


Edited by Jon Isaacs, 17 February 2024 - 11:43 AM.

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#15 David Knisely

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Posted 17 February 2024 - 11:48 AM

Yes, lasers DO work much better than flashlights for pointing at things. In fact, I use one of much higher output level than we are allowed to discuss here. I was merely pointing out, for those who object to the things, that there are alternatives for them.

For constellation talk presenters addressing larger more spread-out groups under less than fully dark skies, the beam from a green laser of the proper safe wattage may not be as easily visible for people standing a distance of more than 15 or 20 feet from the person holding the laser.  This is especially true under moon-lit or near city skies, which is why I still like the flashlight beam solution as the safest and most effective one to pointing out stars and constellations to the public.  Clear skies to you. 


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#16 csa/montana

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Posted 17 February 2024 - 12:17 PM

AAs Jon pointed out, there is absolutely no discussion of lasers above 5mW!  So, if members wish this discussion on flashlights to continue, follow the TOS, please!


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#17 NinePlanets

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Posted 17 February 2024 - 02:22 PM

Air clarity has a lot to do with beam visibility too. At our sites up high (10,000 feet) on a clear, dry night it is hard to see any beam. When the air has smoke or dust in it, visibility is tremendously enhanced.

 

At lower altitudes beams seem to be more effective. More moisture in the air I suppose. When some one drives their truck down the dirt road behind me, man! Any beam works fine - even red I'd bet!  :)



#18 Bill Weir

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Posted 17 February 2024 - 03:26 PM

The difficulty I have with flashlights is that you have to use white light. This reduces dark adaptation which makes it difficult to point out fainter stars you might want the person/people to see. Already there is enough trouble with people at public events wandering around with their phones and their bright screens. They also tend to turn its flashlight on so they can see where they are going which further diminishes their ability to see in the dark. It’s like a vortex of doom drawing them down to ever reduced dark adaptation. 

 

I’m more a fan of actually spending the time to get them to see the sky. “See those three stars that make a little triangle and the two fainter stars off to their right? No those three stars. Come closer so you can see exactly where I’m pointing. OK now follow those four stars in a curved line going up from the two stars. Got it? OK now look in the Telrad and see where the scope is pointed.” I find this way the person/people actually learn how to pick out patterns in the sky. 

 

With regards to lasers, in Canada their use is tightly restricted. https://tc.canada.ca...legally-safely#

The Royal Astronomical Society of Canada has a license of agreement which allows some of us members to use our 5mw under certain circumstances. Even so I rarely bring it out.

 

Bill


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#19 NinePlanets

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Posted 17 February 2024 - 04:10 PM

You're right, Bill. Showing small numbers of people by pointing with the arm and describing it is by far the best way, no doubt.

 

Some folks here do the "outreach" thing with larger groups where the more intimate approach pretty hard to do without some sort of pointing device. Since many are opposed to lasers, I thought I would mention that flashlights will do the job just as well as they did before lasers were available.

 

As for real star parties where those present are all knowledgeable astronomer types? No, I would never use nor advocate the use of any kind of light emitter beyond the little red LED flashlight I carry in my parka pocket. I frown on the use of computer screens too.

 

It seems some here mistook my intended meaning when I started this thread. We can end it now. Sheesh!



#20 Phil Cowell

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Posted 17 February 2024 - 04:11 PM

There is a reason most major star parties ban lasers. 


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#21 havasman

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Posted 17 February 2024 - 06:38 PM

I’m more a fan of actually spending the time to get them to see the sky. “See those three stars that make a little triangle and the two fainter stars off to their right? No those three stars. Come closer so you can see exactly where I’m pointing. OK now follow those four stars in a curved line going up from the two stars. 

Yes!

 

I did a fair amount of outreach back when I was involved with the local club. We had groups of 15 kids, double-digit busloads of girl scouts, thousands of celebrants of the Japanese moon viewing occasion, dozens of people at local parks and we worked from semi-rural roadsides, the big park in the middle of downtown Dallas, schools and parks all over the area and about anywhere we could set up. I never used or needed a laser or really any light. I showed folks the objects by describing their locations and how to determine them the same way I learned to see them. Starting with some obvious object, planet or star usually, I'd walk them through a series if idents to arrive at the object. Or I'd start somewhere and trace the outlines of a constellation for them by making it possible for them to find the spots by standard amateur astronomy techniques: mostly plain old naked eye star hopping. It worked. Tracing Draco for @ 40 people one night from a common space lawn in their borderline rural but bright gated community was a highlight. We started at Vega and by the time we'd threaded through all the bright stars to see the dimmer constellation stars they understood better why it's known as a dragon. And they saw a value in darkness. And they could place themselves alongside ancient peoples wondering and making sense of the sky. And maybe one or two of them remembers the location of the dragon once in a while if they notice Vega.

 

To me using a laser to show folks the sky is mostly like taking a pill to lose weight instead of changing your input/output balance and personal habits. You may get the weight down but you left aside the bigger benefits.


Edited by havasman, 17 February 2024 - 06:41 PM.


#22 Inkswitch

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Posted 18 February 2024 - 09:11 AM

It’s like a vortex of doom drawing them down to ever reduced dark adaptation.

A wonderful turn of phase and very accurate.  I once had a gentleman come up to my scope at a private party, he couldn't see where to put his eye so he turned his white light head lamp on.



#23 kathyastro

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Posted 18 February 2024 - 10:11 AM

At our regional star party, laser pointers were banned when their use was restricted.  As an alternative, outreach presenters started using collimated Maglites.  A shield was taped to the front of the flashlight, like a dew shield, to prevent stray light and to confine the beam. 

 

While not as effective as a green laser, it is still remarkably effective, and stray light (accidentally hitting a tree, for instance) is not as harmful to night vision as laser light is, nor is the direct light damaging to the eyes as laser light is.

 

Once government regulations were clarified, the society started training authorized laser pointer users.  But the star party only allows laser use by trained and certified people, and only for scheduled outreach presentations.


Edited by kathyastro, 18 February 2024 - 10:12 AM.

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#24 Mike Q

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Posted 18 February 2024 - 11:01 AM

To test the effectiveness of Energizer Ultimate Lithium batteries non-rechargeable batteries, I put the Orion Skyline Deluxe laser pointer in the refrigerator for several hours then tried it on the night sky. It worked fine with a strong green beam of light. It's important to not confuse these lithium batteries with the rechargeable ones. The non's are 1.5v and the recharge's are 1.2v. It makes a difference borg.gif

I have 2 of those Orion lasers and yep they are fine down to about 35 degrees.  If you leave them in your pocket and are just using them as a pointer they are fine.  Leave them on a scope as a finder set up, well you better put a heater on them and even then they will start to crap out around 20 degrees.  It isnt so much the battery, its the laser itself.  I switched to a Z Bolt cold weather laser and the issue has gone away.  The use of a lithium battery is always a plus and recommended when the temps are below freezing.  


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