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smallfreak

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Aug 14, 2018
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Hello there :)

I've learned that no matter what problem you might have, there is a forum out there that handles just that. So there you are.

As my headline might suggest, my background is astronomy. I'm not a Laser power junkie, although I can share the fascination of the matter - I'm just deeply frightend by the potential danger :eek:

The post of the poor guy who burnt his eye in a fraction of a second when his laser dropped off the bench is just what I imagine when I read about people fiddling around with this stuff in their spare time just for fun. Similar to the people growing poisonous plants or breeding dangerous animals - or jumping off a cliff with a wing-suit.

Our astronomy club started to use laser pointers at star parties to show the constellations some years ago. First the available <1mW red ones, later green pointers when they where affordable.

The reason why I'm in here is, that I lately found my "<20mW" pointer broken. Damaged by a spilled battery that I left in. That hurt me, since the pointer was quite expensive when I bought it. A little research showed me, that prices have dropped dramatically since. And that the wattage increased dramatically too.

I have a hard time to find something I might safely use on a star party with children running around in the dark.

Like it is in most countries, public use of a Laser stronger as 5mW is restricted here with a few exceptions like trained personal for astronomical use. For good reason.

Usually I'm not one of the "buy first, ask later" guys, but I already ordered a cheap pointer from laserpointerpro as a replacement for my broken one, before I hat a deeper understanding of the mater. Only later I learned that the usual safety measures are not standard anymore, like the propper shielding of unconvertet IR from the pump diode. While this might be no problem for the burn-holes-everywhere fraction, that would not want to waste a single milliwatt, visible or not, it might be a problem for my use.

The 20mW I had was a real bummer at night. Totally sufficient to point to the stars. Now I read that I might not only get 20mW green light, but another 200mW invisible radiation as bonus with such a cheap pointer. :cryyy:

And then they offer 50mW green pointers on a keychain as "an ideal gift for your children"... Well, there are countries, where minors are allowed half automatic guns, so this does fit in. :undecided:

While this order is already shipped, I might decide to just dump it on arrival and count the money to the learning budget, when anyone can recommend a safe device with a good beam quality, reasonable priced and well below the 100mW range. I don't want to risk someones health and I don't want to attract any officials that want to look who is operating a "Laser weapon" in the backyard since the source of the beam can easily be tracked down, due its very nature of usage. And I might have troubles getting it through customs.

So, that's me.
Nice to meet you.
 

RB astro

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Welcome sf.
I use my original 20mW for astro as well and I'm always worried I might leave the AAA batteries in by accident, as I fear the battery leakage as well.

I do astro-photography, btw.

I'll let others recommend something to you as I haven't got any recommendations to offer, unless you want to build something yourself.
I usually build mine using a Vape system used by smokers.

Also, it would be helpful if you state your 'general' country or location in your bio and post, since this with guide the members when giving you advice.

Cheers
RB
 

smallfreak

Member
Joined
Aug 14, 2018
Messages
77
Points
18
Hello RB,

thanks for the welcome. I added my location to the profile. Good idea.

I'm in Austria. Great place for Astronomy, as we have plenty of dark mountain sites and only moderate light pollution. Not comparable to namibia, but a dark site within reach from virtually any place when there is a promising evening.

I had placed my scope in the backyard to watch the current planetary parade and to show the constellation to my neighbours. The milkyway as easy sight even in a normal rural place. Constellations dissolved in a great starred sky. So out with the pointer to show their shapes - ah - no.

When I bought my 20mW I paid >150€ for it, so I shed a tear when I found it dead. With a 100mW torch for $5 including shipping, you may rethink about changing the battery or just buying a new one. Or one can order a bunch for spare. :undecided:

A leaked battery is not as expensive as it was before.
 

Gazen

Active member
Joined
Nov 13, 2017
Messages
511
Points
43
Welcome to the forum

In the future you should avoid laserpointerpro, they misrepresent and overprice their items. If you go to the "companies" sub forum, you'll find a thread on reputable companies to buy from, a little outdated, but still serviceable. Check out laserglow if you want a high quality 5mW pointer, or sanwu and jetlasers for something of higher power.

Good luck
 

paul1598419

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Sep 20, 2013
Messages
14,363
Points
113
Actually the amount of IR "leaking" out of these 532nm lasers is on the order of 16% and it is not well collimated like your green light is. So, if you are using it to point at stars, you have nothing to fear from them as long as you don't leave one on while not in your control. You can get the 303 532nm green lasers on eBay for $10.00 including a Li-ion battery and a charger. These generally come in between 50 mW and 80 mW. Just use the same common sense that you did with your 20 mW one and you'll be fine. If you have trouble finding one, just search eBay for 532nm laser pointers.
 

smallfreak

Member
Joined
Aug 14, 2018
Messages
77
Points
18
Check out laserglow if you want a high quality 5mW pointer, or sanwu and jetlasers for something of higher power.
Thanks fo the suggestions. I read some coments about the Laserlands 520nm 5mw pointer. That seem to be quite bright for the nominal values.

For astronomy use the 5mW range of the tested pointers was not quite enough to have a group of people around the astronomer have a good sight on the beam in a moonlit night. We had good experience with 20mW green pointers whereas 50mW were too bright in a dark night as it affects night adaption.

The range >5mw .. <50mw seems a bit under represented on the market, or at least in the shops I found. It may be because a good share of the users here tend to more powerful devices. This observation may be biased.

If I go for a higher power, I probably have to dim it down or maybe close the aperture to a tiny hole.

What concerns me a bit is the beam quality/divergence. My broken pointer had 1.2 mRad but the ones I have researched so far do either not state anything about it or are at least twice the size.

I have no problem paying $20 or $60 on a quality pointer. I do have a problem arguing $200 with my beloved wife. :whistle:

I will not buy anithing from laserpointerpro, I promise :beer:
But I will wait and see what the spent $15 will be worth. Could still be, the pointer will be usable.
 

paul1598419

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Sep 20, 2013
Messages
14,363
Points
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Thanks fo the suggestions. I read some coments about the Laserlands 520nm 5mw pointer. That seem to be quite bright for the nominal values.

For astronomy use the 5mW range of the tested pointers was not quite enough to have a group of people around the astronomer have a good sight on the beam in a moonlit night. We had good experience with 20mW green pointers whereas 50mW were too bright in a dark night as it affects night adaption.

The range >5mw .. <50mw seems a bit under represented on the market, or at least in the shops I found. It may be because a good share of the users here tend to more powerful devices. This observation may be biased.

If I go for a higher power, I probably have to dim it down or maybe close the aperture to a tiny hole.

What concerns me a bit is the beam quality/divergence. My broken pointer had 1.2 mRad but the ones I have researched so far do either not state anything about it or are at least twice the size.

I have no problem paying $20 or $60 on a quality pointer. I do have a problem arguing $200 with my beloved wife. :whistle:

I will not buy anithing from laserpointerpro, I promise :beer:
But I will wait and see what the spent $15 will be worth. Could still be, the pointer will be usable.
I have used the 303 532nm green pointers at night to point to stars and even at 80 mW they aren't too bright to cause anyone discomfort looking at the beam. For $10.00 with a battery and charger you could do a lot worse than one of these. Some seller like Sanwu and laserpointerstore use these same pointers and sell them for $20.00 alone....no battery or charger. Most will come in between 50 mW and 80 mW, so in that respect it is sort of a crap shoot. But, it is your decision.
 
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smallfreak

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Aug 14, 2018
Messages
77
Points
18
I have used the 303 532nm green pointers at night to point to stars and even at 80 mW they aren't too bright
I spent a while on eBay to sort out the offers and I found a lot of 301 and 303 "lookalike" pointers that are advertized like "<1mW, high power, lights matches". This can only be nonsens, is it? Shouldn't these pieces be more or less quite powerful pointers, way beyond the <1mW range (and way below "burn maztches")?

Is this some kind of "if you want this, you already know what you will get. We keep specs within legal values :eg: "
 

RB astro

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I spent a while on eBay to sort out the offers and I found a lot of 301 and 303 "lookalike" pointers that are advertized like "<1mW, high power, lights matches". This can only be nonsens, is it? Shouldn't these pieces be more or less quite powerful pointers, way beyond the <1mW range (and way below "burn maztches")?

Is this some kind of "if you want this, you already know what you will get. We keep specs within legal values :eg: "
Yes.
They claim <1mW to get around the eBay rules, but everyone buying them knows that they are a lot more powerful, especially when they say they can burn matches etc.

Now I know the budget is tight but you may want to think about building your own.

A nice little 505nm, 35mW would be ideal and you don't need to worry about the cold weather affecting the laser like a 532nm would.
Have a look at my build thread below.

"My tiny green giant"

DTR sells the diode/modules + driver but you'll need to put it in a host and run it off one 18650 battery (or similar).

Also, speaking of The Milky Way, just wanted to share a photo with you that I took out of my back yard.
I can only imagine how wonderful the Milky Way would look from your dark location.




Cheers
RB

:yh:
 

smallfreak

Member
Joined
Aug 14, 2018
Messages
77
Points
18
Now I know the budget is tight but you may want to think about building your own.
It just got a little tighter, as I found my trusted old Weller W 61 C soldering iron is the next one that went over jordan. After my LX-200 Telescope handbox (blewn capacitor took flexi cable with it). Luckily I got a replacement keypad and a handful of MLCC to replace the aged tantals. Now that I'm half way through the repair, the soldering iron passed away.

Some times are tougher than others.

A nice little 505nm, 35mW would be ideal and you don't need to worry about the cold weather affecting the laser like a 532nm would.
Great piece :drool:

WHile I know which end of the soldering iron is safe to touch, I have no mechanical skills and no proper tools.
Also, speaking of The Milky Way, just wanted to share a photo with you that I took out of my back yard.

I can only imagine how wonderful the Milky Way would look from your dark location.
Wooha! Great shot. Your sky quality is certainly even with our observatory site. I'm not in the photography business, I'm almost exckusive visible anstronomer. My first images on Comet Hale-Bopp (in ancient times) and my last ones on the '99 Solar Eclipse. On chemical film. I leave the astrophoto endeavours to my club members who buy equipment that could probably pay off my house. :thinking:
 
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lasersbee

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Welcome to the Forum...
Nice detailed introduction...:gj:
Enjoy your stay.


Jerry
 

BowtieGuy

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Welcome to LPF, smallfreak! :wave:

Have fun, stay safe, and enjoy your stay! :yh:
 
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smallfreak

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I don't know, but that member name sure seems provocative to me. I half suspect it's a taunt at RB. We have some folk a bit miffed at moderators lately. Just saying.
Mine? "smallfreak"?

Sorry, I don't want to offend anyone. My older brother used to call me such. In contrast to him "BigFreak" :-D

I use this occasionally to leave some breadcrumbs in the world that he might want to follow if he stumbles across them. A sad story not suitable to be placed here.

I'm going to see if I can get it changed. And I might see if I can upload an avatar so you have a face to look at. I don't have to hide. Anonymousity was before Snowden. Big Brother is watching us, if we try to hide or not.
 

RB astro

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I don't know, but that member name sure seems provocative to me. I half suspect it's a taunt at RB. We have some folk a bit miffed at moderators lately. Just saying.
Thanks for looking out for me Chris.
It's ok, smallfreak is legit and is a very nice guy.
We'll be helping him out as much as possible.



Mine? "smallfreak"?

Sorry, I don't want to offend anyone. My older brother used to call me such. In contrast to him "BigFreak" :-D

I use this occasionally to leave some breadcrumbs in the world that he might want to follow if he stumbles across them. A sad story not suitable to be placed here.

I'm going to see if I can get it changed. And I might see if I can upload an avatar so you have a face to look at. I don't have to hide. Anonymousity was before Snowden. Big Brother is watching us, if we try to hide or not.
It's all good buddy, no need to change the name.
If you're happy with it, so are we.

RB

:beer:
 

Pelagius

Active member
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Jul 1, 2018
Messages
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Welcome smallfreak!
I did not know there was an Astro Thread! One of my favorite topics!
 




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