I'm looking to buy a green laser pointer to use while observing, but I am not sure what brand or power to get. I see that on Telescopes.com they have an Orion 5mW one for about $100. But I also have seen other companies selling "true" 5mW ones that they say are more powerful/visible for about the same amount. They claim that "other" company's lasers are really 3mW-5mW.

What do some of the BABB members think? What do you use, and what would be the best laser buy for my money? $100 or so is my budget.

Thanks!

CJSF

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Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

I saw one used for the first time the other night and instantly wanted one. I searched E-Bay and found this:

http://cgi.ebay.com/Green-Laser-Poin...QQcmdZViewItem

It looks identical to the one used by the lecturer. His (rated <5mW) was powerful enough that I imagine even 3 mW would be fine.

I'm tempted to get it, but I've never bought through Ebay before. Don't worry about the bid time. Every time the bidding ends, he puts up a new one.

Green? Don't know if a laser pointer that has the wavelength to which we're most sensitive is the best for protecting dark vision.

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Freedom For Fission A breath of fresh Iodine-131

I am curios, Glom. What do you mean?

Normally, all lighting is red so as to protect dark vision when observing.

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Freedom For Fission A breath of fresh Iodine-131

Using an infrared laser pointer would be guaranteed not to spoil your night vision.

It's not used for general lighting. A green laser scatters more than a red, so it's more likely to produce a visible beam. That makes it more useful for pointing out stars to a group of people.

Green is what I've seen every amatuer astronomer with a laser use. The beam is visible, but doesn't really affect the night vision. It's particulary useful at star parties and public viewing events. It projects a visible beam that appears to reach all the way to the star/planet you point it at. A red laser's beam is not visible in this way (unless it's REALLY hazy or smoky).

CJSF

__________________
Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

Interesting. If you ever have been a hobbyist scuba diver* (I don't mean when on holiday!), you are taught about colour loss and diffusion. I never realised the same practical use would be around for 'pointing sticks' in astronomy.

http://www.seafriends.org.nz/phgraph/water.htm#colour

Nick
I used to be, over 100 dives in UK climate!

Well, I hope someone can give me some advice over the weekend. I'm not usually browsing the web on the weekends, so I'll read stuff on Tuesday. I'm hoping to make the purchase next week.

Thanks!

CJSF

__________________
Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

Just received mine after buying on eBay. Cost is under $60.

It is amazing how bright a green laser pointer is. Our eyes are most sensitive to green light. Usually CCD cameras have double the amount of green cells to better capture color as we see it.

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

Wasn't there some sort of homeland security alert a few months ago when a helicopter pilot thought that a laser pointer being used for observation was a rifle/rocket launcher scope?

Always gotta watch for those astro-terrorists!

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These aren't the droids you're looking for.

I have a "<5mW" green laser that I purchased new for $AU150*, so your price range sounds about right. This is amply bright enough for a dark night, but a word of warning - they become fairly ineffective whenever the moon is between first and third quarter.

As a teaching aid on dark nights however, they are outstanding! It's like holding a razor-thin, straight green wire all the way from your hand to the star!

(edited to note - *noting exchange rates & import duties, etc)

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"I'd take the awe of understanding over the awe of ignorance any day." - Douglas Adams

Also note: The better the observing conditions, the worse they get.

The laser pointers barely worked on Mauna Kea (granted, I doubt people would complain about those conditions...but it was COLD!)

Sorry if this seems silly but...

What do you use the laser for?
I'm not exactly an astronomy expert

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here we go, the world is spinning
when it stops, it's just beginning

sun comes up, we laugh and we cry
sun goes down, and then we all die

Touched by his noodly appendage

To point to things in the sky. You can see the beam shine up in the direction of wherever you point it. A green laser pointer is particularly useful for pointing out things at public star parties.

Absolutely, particularly for pointing things out to children...

I think mine cost about £70 in the UK, probably a lot cheaper now, but I have never regretted getting it. It just saves so much time, and is great for tracing out the shapes of constellations too.

Great fun if you have a kitten in the house...

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<span style='color:red'>www.seeviewo.org</span>

People always want to know where the object in the telescope is located in the sky. In addition to pointing out the location, a star hop to it can also be pointed out (assuming you are somewhere that stars can actually be seen naked eye).

It's also useful for pointing out some of the major constellations.

The one I've used can be seen by anyone within about 30 feet of the laser.

I got a 10 mW module for AU$150 from Jaycar Electronics (in australia), mounted it in a case with batteries, and it works like a bought one.

Well, I'm glad that they seem to be useful to many of you. I had a talk with someone at a star party this past weekend, and I think I'm going to go ahead and get the Orion one with the "remote" switch (it's actually a button attached to the back end of the case by a wire). At least it's a recognized brand and returning it shouldn't be too difficult if it's defective.

Thanks, everyone for the replies.

CJSF

__________________
Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

Seeing the photos and description of the laser this guy is selling on eBay, it looks nearly identical to the one I bought from www.thinkgeek.com (it was the original green laser, no longer sold there. Instead, they offer this one (model II)).

Anyway, the one I have is bright, but will signifigantly dim within a few minutes of use. Sometimes the beam actually pulses. Bright when first lit, then immediately dim... then maybe brightening again.

My point is, if you are anal about things, or pay attention to detail, you can end up being a bit disappointed (after the initial "oooo wow" phase wears off).

There was a site that sold "microprocessor-controlled" output lasers that claimed to be exactly 5mW, where most are usually under (hence the <5mW listings).

I hope some others can post their histories with their green lasers. It is a fantastic tool - even to the point of hard-tying to a scope or binoculars so others can see where you are pointed.

Just my $0.02 worth,
-myrkat