Advice on Laser Purchase Requested

[laserjunkie798]

Hi guys! Love the forum. I was wondering if you'd be able to assist me.

A couple of years ago on a trip to Thailand I bought a green laser from one of the market stalls in Bangkok.

It was a thin black pen that looked as far as I can remember pretty similar to this:



It took AAA batteries and came with a bunch of kaleidescope-style attachments. I remember it cost about $10.

It was a fantastic little piece of kit - I was blown away by how powerful it was. At night you could see the beam for literally miles and miles. I had endless hours of fun with it.

Problem is, I lost it a few months ago

I'm wanting to purchase something similar or maybe even a little more powerful but I'm so overwhelmed by all the different options on ebay / amazon etc.

I've had a look in the green laser section on here and it's still a little overwhelming.

I was wondering if any of you could recommend either an ebay or amazon link to something as close as possible to what I've described - I'm happy to spend between 20-30 USD.

Any advice regarding this would be greatly appreciated - thanking you in advance!

 

[CurtisOliver]

Pretty much all of those eBay options are the same inside. The only problem is they are not quality controlled so you could naturally end up with a dud or even get a more powerful unit.
Another option is Banggood. I have done a review on a shorter styled USB rechargeable laser myself, and they have a good power output similar in strength to the 18650 powered 30x series.
You don't even need to keep getting AAA's.

USB Rechargeable Green Laser

 

[paul1598419]

The little green pens that run off AAA batteries are basically all the same and can be had for as little as $3.00 on eBay. I have several from years ago and even have two that do multiple lines. One has four lines and another has six. For the money you would be better off buying a few of them as the quality control on them is not good. Also, the switch on the side tends to get noisy over time, so keep them inside a ziplock bag.

 

[Encap]

More expensive but better quality and metered output see: https://www.optotronics.com/proddetail.php?prod=Opto5

 

[hakzaw1]

Put some 3$ bids.. one will be a winner if you keep at it. and that's 3 lasers not just one.
I am not always eager to help new member with advice BUT not making a proper 'intro' thread , placed in the
'welcome' section.. this needs to be done and its a good idea to finish your profile page. sometimes the help we give changes depending upon WHERE you live. also study up on 'duty/rest' cycling of pointer lasers.. at 13mm it should be quite clear THERE IN NO HEAT SINK IN THESE...

Check these out too.. lots of rainbow fun..
and from there you can see 'other items' and the pointer "trio'' is there..
the X-kubes are very nice..

https://www.ebay.com/itm/1pc-18mm-X-Cube-Dichroic-RGB-Combiner-Splitter-Optical-Prism-Very-Slight/323403149940?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

I just won a KingKube Xkube for 99 cents
he (Alan) is also a new member here: "KingKube''

 

[laserjunkie798]

Thanks for the replies gentlemen. I think I might go with one of the Sanwu Pockets that I'll probably end up purchasing from here:

https://www.sanwulasers.com/product/pocket

However, I would ask for one more piece of advice:

I originally had my heart set on a green laser, but I noticed that one of the options with the Pocket is blue 800mw, whereas the highest green variation only goes up to 150mw.

Does this really mean the blue one will be over 5 times more powerful? I'm not really that interested in burning things - I just like seeing how far the beam can go.

Once again, your input is greatly appreciated!

 

[smallfreak]

Does this really mean the blue one will be over 5 times more powerful? I'm not really that interested in burning things - I just like seeing how far the beam can go.

Yes, this means the beam is 5 times more powerful and 5 times more dengerous. Before playing around with such a device, you should take every possible precaution and wear proper safety goggles. Just because the laser comes in a handy size does not imply that this is in any way easy to handle. 800mW blue Laser can instantly blind you (or someone else), if you accidently hit a shiny surface when pointing around. You can burn a permanent hole into your retina before you can even blink - and that is no metapher. The damage is done much faster than the eye can react to the bright light. When the lid shuts, it's already too late.

So you should touch it like you would touch an upset rattlesnake.

Please read the "Laser safety" part here to get an impression what you will get when buying a portable class IV Laser and what troubles you can get when anything goes wrong. The unknown part in "see how far it goes" is what you eventually might hit at the far end.

We had once tried to shoot a 20mW green laser acros the valley onto a retro reflector we placed at a mountain peak 10km away. The reflection was seen easily. So you can expect such a laser to go all through the atmosphere right into outer space. You can follow the beam until it reaches virtually infinity. Certainly this "infinity" is somewhere in the lower atmosphere, but far enough to essentially make no difference. That makes it a great star pointer, as long as you stay away from planes. 100mW will not show a longer beam, just a brighter one. 800mW either.

Btw. We had the "strong blue" against "cheap green" discussion here some days ago. The eye is so much more sensitive to the green light, that 150mW green looks brighter than 800mW Blue. So you gain nothing when buying the blue one with respect to beam visibility, other than the blue one is much more dangerous.

 

[ragebot]

Thanks for the replies gentlemen. I think I might go with one of the Sanwu Pockets that I'll probably end up purchasing from here:

https://www.sanwulasers.com/product/pocket

However, I would ask for one more piece of advice:

I originally had my heart set on a green laser, but I noticed that one of the options with the Pocket is blue 800mw, whereas the highest green variation only goes up to 150mw.

Does this really mean the blue one will be over 5 times more powerful? I'm not really that interested in burning things - I just like seeing how far the beam can go.

Once again, your input is greatly appreciated!

Disclaimer: I am one of the newer members here so others may well correct me.

As a rule most lasers have an advertised power that seems to be determined by some type of witchcraft normal humans are not able to understand. That being said Sanwu is a well respected company that has good quality control so I would trust their power claims.

If you search here for some threads on wave length you can get lost in the details. But the Cliff Notes version is you can't really compare power ratings for different wave length. To make things even more complicated the diode that produces the laser beam has properties that affect the beam. One of the most important factors is what is called divergence. In simple terms this means the greater the distance the beam travels the bigger the dot (don't take the term dot too literally) gets. Since the number of photons emitted by the diode is constant (again don't take this too literally it does vary for several reasons) as the dot gets bigger the number of photons hitting the same area decreases; and once it reaches a certain density you can no longer see it.

There is an attachment called a Beam Expander, or BE, that controls how fast the dot gets bigger, which means you can see the beam at a greater distance. Perhaps more important is how well the quality control is in placing the diode and lens in front of it in the correct alignment.

Most humans see better in the green wave length so even if a laser in another color was more powerful that would not mean you could see it better.

 

[hakzaw1]

actually 50mW of green is as 'bright' (to our eyes) as 1W of 445.

and when talking about preceived brightness-- to double in brightness you need 4X more.. IE 100mW is one half as bright as a 400mW so 4:1 NOT 2:1..
AND by no means am I suggesting careless use,, IF it were true about instant blindness... how come we read so little about serious laser accidents.
The last I can remember in the news was loss of vision in one eye by a Burning Man 'ranger' she and her fellow rangers had been looking hard for the a55hat shining a green laser at people then running,, so w/ ~85,000 attendees he was not going to be easy to catch.. She had spotted him and he began to single her out and as she was watching him and ended up taking several hits to her eyes and she was intently watching him... they were IIRC some distance apart. she took many eye hits --so many that she lost all vision in one eye and some damage to her other eye.. BM had no insurance or help for the ranger (who work btw--BM w/o getting paid.)
She got injured by multiple eye hits.. otherwise a single hit w/ our .25 seconds
'blink' reflex. would have greatly limited the injury .. the other reason this gal got such serious injury was the horizontal beaming -- this allowed her own eye's lens to be a factor.. it can magnify the power by several hundred or much more.
Can the sun start a fire?? YES it can --when a magnifying glass is between the sun and object getting burned... so am I suggesting careless lasering? NO but at the same time-- the reality is.. when used w/ good safety sense.. we will survive w/ our vision in tact.

A go-fund-me acct has been set up.. and there were lots of donations--for Ranger Kelli..I sent some$$ -- you should too...
https://www.gofundme.com/eyebeam

 

[laserjunkie798]

Guys I'm blown away by your detailed and informative replies. Thanks so much for taking the time to both advise and caution me.

In the end I went with one of the 100mw green versions of these guys: https://www.sanwulasers.com/product/304

I think that will be more than enough for my purposes. Thanks again!

 

[hakzaw1]

lj 798please finish your personal profile--don't be such a stranger.. advice/help varies dependent upon WHERE you are located