noob green laser question for astronomy

[astronewbie]

id like a recommendation for a green laser
that is potent enough
but doesn't burn stuff or
heat itself much either,
and can be pointed to stars clearly in a light polluted night sky.

im a noob in lasers and astronomy (where i intend to use it):
my goal is to fit it inside this little bugger here:
Laser Pointer Bracket for Celestron SkyScout | Orion Telescopes

which is a pointer that attaches to this thing here
SkyScout Personal Planetarium (item #93970) / SkyScout / Products / Celestron.com

which allows u to identify stars, galaxies, messiers...etc in the night sky.

plan is:
once gfriend points the above contraption to a target,
ill move my telescope to fetch it.

problem is,
lasers sold to amat. astronomers are overpriced and weak ($100 for 5mW),
and aa's complain about 5mw being barely visible,
but once anyone suggests going higher,
the forum gets sort of shutt off because of the "it's illegal" gang,
that assumes everyone is a retard and will flash it at people's eyes and airplanes.

sorry for the long rant and explanations,
im just trying to spend wisely...
tks for reading.

 

[Asa]

Here's a 30mW laser from DinoDirect.
30mW 532nm Handheld Green Laser Pointer Pen(1 x 18650 included) - DinoDirect.com

Not guaranteed it's 30mW, but I'm sure it's stronger than 5mW. I looked at the bracket you're trying to put this in, it goes for the skylaser 5mw which is about 6 inches long. It was hard to find a 30mW this long, but this one will probably be close as it takes 18650 batteries. This also has a tail clicky as opposed to side which I figured would be more convenient.

Here's one that's a bit more expensive and stronger from O-like (a more reputable dealer).
50mW transformable green laser/adjustable/burning [OLV50] - $41.99 : Welcome to O-Like.com, Your source for laser products

It'll definitely be ~50mW and is focusable unlike the one above. It's also a 18650 so it should be long enough for your bracket. Side button like the skylaser one, this is momentary though (not sure if the skylaser is) meaning you have to hold the button down. It looks like the bracket has some sort of mechanism to hold it down for you though; it's something to look into.

 

[astronewbie]

tk u for ur answer,
will look into them.

excuse my ignorance,
what is the advantage of a 18650 battery ?
is it a cheap battery ?
how does it compare to AA and AAA ?

 

[Ash]

tk u for ur answer,
will look into them.

excuse my ignorance,
what is the advantage of a 18650 battery ?
is it a cheap battery ?
how does it compare to AA and AAA ?

The advantage is their high capacity, and the ability to run a laser for longer without changing the batteries as often. As well as being rechargeable.
I think you want something that takes AA batteries, so you can easily replace them, as 18650's are hard to find at a store in the US.
And, you probably don't want a focusable, as you will just be pointing to the stars, and don't need to focus the laser for burning things.
Also, I think if you want to have any chance of seeing your laser in a light-polluted sky, you want at least 50mW.
Recommend: http://www.ledshoppe.com/Product/ledp/LP1076.htm
A great price for a true 50mW laser.
One problem that I see is that these pen-size lasers have a momentary button, so (as Asa pointed out) you (or your wife) will have to hold the button down to see the laser.
One option would be to get a constant-on laser (with tail clicky), but finding a laser that takes AA batteries and has a constant-on is difficult.
I would recommend this one: www.rayfoss.com
It is waterproof (to 3 meters), and can be run for longer cycles than a smaller pen laser, but it takes a CR123 battery, and unless you have a charger, or are willing to invest in disposable CR123's (very expensive), you may not want to get this one.
o-like also has a good laser for your needs: Pocket compact Green laser 50mW [OLPG50] - $28.00 : Welcome to O-Like.com, Your source for laser products

 

[AJ_Dual]

18650 is a very common Lithium Ion rechargable battery, and capacities range anywhere from 1500 to (claimed) 3000mAh.

Physically, they're a little bigger than AA's, and are very commonly used in RC cars, and laptop batteries.

Their use in laptop batteries has put a lot of industry attention on them, and the 18650 has had a lot of technological progress in terms of it's chemical formulation, and storage capacity over the years. So if you buy a really reputable name-brand one like AW, Pila, LG, Sanyo etc. it'll have good life-span, good discharge characteristics.

 

[Asa]

How long would you be keeping the actual laser on? If it'll only be for a few seconds, a pen host is probably what you want (skinnier, less weight). If you have to keep it on for extended periods of time (30 seconds+), you should look into larger hosts, like flashlight hosts, with better duty cycles than pen hosts so you don't damage your laser.

 

[astronewbie]

id say more than 30 sec,
unless the 2 people r in good synch:
one person locates the object,
the other tries to aim the telescope towards the laser quickly.
how bigger in diameter are flashlight hosts ?

 

[Asa]

It all depends on which host. Some are quite thin, maybe a half inch in diameter, and they can go up to a few inches.

Why don't you try doing some of your own research? The skylaser is 6 inches long, and I'm not sure how long of a laser your bracket needs to hold it in, but most sites provide laser dimensions. Just go for a thicker laser (not a pen) with ~50mW of power that's also around 152.4mm (unless you figure out how long of a laser you can use).

List of what to look for:
-If it's a click on-off or momentary clicky (and if your bracket can support a momentary clicky)
-Dimensions
-Power
-Battery types (search on this forum for comparisons, but I recommend 18650 or CR123As).

Some low-priced, decent quality laser sites:
www.rayfoss.com
www.o-like.com

 

[astronewbie]

cool,
tk u all.

 

[Fonduman]

at 50mW heat is unlikely to be a problem, unless its a pen host. any host thicker than a pen host will probably be fine so long as it has a clicky switch and fits your laser holder thing.
i'd like to see the reactions of the "its illegal" people if you brought an 800mW hercules with you one day :crackup:

may I also point out the probable need for a green laser specificaly made for pointing?
to summarise: generally, the smaller the beam diameter at aperture, the greater the divergence of the beam with distance. some info:
http://www.wickedlasers.com/laser-tech/laser_beam_comparison.html
I know WL havent been too reliable in the past, but they are claiming this laser to have very low divergence, if you want to look into it:
http://www.wickedlasers.com/lasers/Executive_Pro-81-37.html
pen host though. but good to bear in mind the divergence/diameter idea.

 

[RA_pierce]

The pointers linked to above are good for casual use, but since you have a specific need, I would say you should spend a little extra and get something that will work right.


I would recommend these:

X15 Compact Portable Laser - X-Series - Novalasers Inc.
You can get 5% off at NOVA with coupon code WARP5.

Laserglow Technologies - Handheld Lasers, Alignment Lasers and Lab / OEM Lasers

Z-Bolt&#174 ASTRO-10 plus Green Laser Star Pointer - 5 Mile Range, Lithium Power

Z-Bolt&#174 BTG-2S plus Green Laser Star Pointer - 5 Mile Range, 3 Finishes, Visible Beam

Most cheap greens from places like Rayfoss, Dinodirect, o-like, etc. are very unstable.
Even 5mW pens I have ordered from Places like Dealextreme and O-like are very unstable. Some do not function well outdoors at night due to the cooler temperatures.

5-20mW is enough to be visible at night in clear skies and not overwhelm you.
50mW is too much if you are going to be looking for distant stellar objects.

 

[astronewbie]

newbie just read
http://www.nist.gov/customcf/get_pdf.cfm?pub_id=906138

newbie asks,
out of all these recommendations,
do all of them come with infrared filters or
is there IR leakage risk ?

 

[Asa]

newbie just read
http://www.nist.gov/customcf/get_pdf.cfm?pub_id=906138

newbie asks,
out of all these recommendations,
do all of them come with infrared filters or
is there IR leakage risk ?

There is ir leakage risks on the ones that don't specifically say they don't have ir filters (most of the above). It won't be a big deal if you're just pointing the laser away from you though. And if you are really concerned about it, then get a ir filter and glue it to your laser.

All the lasers RA has recommended are <5mW (I believe). I have an "overspec" 5mW eBay laser that's probably emitting at about 20-35mW and it's barley visible at night (if you walk too far away from it, it disappears quick too). He says "50mW is too much if you are going to be looking for distant stellar objects," but I don't believe that's what you're exactly using it for.

You're using it more for the machine and you're using binoculars, not a telescope. I would suggest using more than 5mW, more like 30-50mW (though I'm not an expert).

Just make sure you find a laser that fits your bracket! Some of these lasers may be too small, I'm not sure exactly what's the smallest you can get before it's too short to fit in it. ~6in will work though.

*Edit: I take back the statement about my ~30mW greenie being "barely" visible. It's clearly a solid beam, I think it would be pretty adequate for what you're doing.

 

[TheRunner]

I would use 30 mW.

 

[Flaminpyro]

You should give Scopeguy20 a PM if you havent talked to yet, He will most likely be able to help you, see his name, Scope guy as in telescope