Green Laser Pointers...Power limit???

[Garyh]

I have been reading this thread ever since my return from holidays and was myself thinking of getting a ebay cheapy....but after all the bad things I have heard I don`t think I will bother..
Does anyone recommend any sellers in Auzz? Are the Andrews ones what they are quoted at and good brand name?
One thing I have noticed also is the beam widths are different with lots of them? Would a 5mw with a .8mm beam be brighter than a 10mw with a 1.5mm beam? and the quoted rad value is it better the lower it is?
I need it to work under dark and also clear air as I don`t have too much pollution and haze at home so still wondering if a good 5mw would be plenty?

Cheers Gary

[DJVege]

I'm just a noob, but I'm VERY certain that you should go no higher than 10mW. It's more than enough. I'm sure someone can tell you which of andrews, bintel etc... are better.

Cheers.


...DJVege...

[Ingo]

Originally Posted by Garyh

I have been reading this thread ever since my return from holidays and was myself thinking of getting a ebay cheapy....but after all the bad things I have heard I don`t think I will bother..
Does anyone recommend any sellers in Auzz? Are the Andrews ones what they are quoted at and good brand name?
One thing I have noticed also is the beam widths are different with lots of them? Would a 5mw with a .8mm beam be brighter than a 10mw with a 1.5mm beam? and the quoted rad value is it better the lower it is?
I need it to work under dark and also clear air as I don`t have too much pollution and haze at home so still wondering if a good 5mw would be plenty?

Cheers Gary

A 5mW with a .8mm beam will be brighter than a 1.5mm beam. There is more light condensed into an area, where 1.5mm is more spread out. Also a thinner more focused beam is better for burning.

mRad is milliradius and that shows you divergence. The lower the number, the less the beam spreads in distance. Usually, you'll get <1.2mRad.

20mW is more than enough for astronomy, but if you want something to stand out and make other astronomers jealous/mad, check out lucentoptics.com, they'll ship anywhere

[starstruck]

The two main reasons people go to ebay for laser pointers is cos of convenience and low prices.

In the end you normally end up out of pocket and don't even have a laser to show for it.

Lasers are missing IR filters which makes them dangerous and gives exagerated power readings. The lasers are also often pot modded (power is boosted) which makes the lasers unstable and likely to burn out.

Unless you are buying from a seller with an established rep, stay away from ebay.

An excellent alternative is Dragonlasers at www.dragonlasers.com

Their prices are pretty much as low as you can get for a genuine high quality laser pointer and they have outstanding customer service.

They even sell lasers that have no duty cycle and an on/off switch which makes then ideal for mounting on a telescope http://dragonlasers.com/hulk

[Ingo]

Originally Posted by starstruck

The two main reasons people go to ebay for laser pointers is cos of convenience and low prices.

In the end you normally end up out of pocket and don't even have a laser to show for it.

Lasers are missing IR filters which makes them dangerous and gives exagerated power readings. The lasers are also often pot modded (power is boosted) which makes the lasers unstable and likely to burn out.

Unless you are buying from a seller with an established rep, stay away from ebay.

An excellent alternative is Dragonlasers at www.dragonlasers.com

Their prices are pretty much as low as you can get for a genuine high quality laser pointer and they have outstanding customer service.

They even sell lasers that have no duty cycle and an on/off switch which makes then ideal for mounting on a telescope http://dragonlasers.com/hulk

dragonlasers.com are good. They started with a bad reputation but have since built it up. Their pen pointers are made by CNI, and I recommend you stay away from them. The PGL III's are also made by CNI, but are better quality.

Soon lucentoptics.com will have the PGL III's for a lot cheaper than dragonlasers.com. Right now they sell the smaller PGL IIIa's.

[Johnofwa]

I've just received my 240 mw 532 nm green laser from ebay!!
Looks like this is all too much and dangerous. Should I put it away and get a real one from Aus somewhere ?

[DJVege]

Hey mate, did you get it from "i.web". A few things you can learn from this thread:

1) There is no way you will EVER get a REAL laser POWER higher than 15mW from ebay. It may be a 240mW diode, but if you shine your laser onto some plastic and the plastic isn't burning in under 5 seconds, then it's not a true 240mW laser...just a 240mW diode.

2) That laser you have is dangerous because it won't have an IR filter. I haven't been able to pull mine apart to check, but I'm fairly sure it doesn't. You can still use that laser, but because there are wavelengths coming out of it (invisible) that are extremely dangerous to your eye sight, it would be best to buy one from your local astronomy shop (I haven't heard any reviews on Bintel, myastroshop, telescopes-astronomy etc... and their lasers).

In any case, read this thread and you should get all the info you need.


...DJVege...

Originally Posted by Johnofwa

I've just received my 240 mw 532 nm green laser from ebay!!
Looks like this is all too much and dangerous. Should I put it away and get a real one from Aus somewhere ?

[74tuc]

Hi all,

Just to clarify a point re:

"mRad is milliradius and that shows you divergence. The lower the number, the less the beam spreads in distance. Usually, you'll get <1.2mRad."

mRad actually stands for milli-Radian (1/1000 of a Radian). Radian is a unit of angular measure like degree is.

1 Radian. = 57.296 degrees

1 mRad = 0.057296 degrees = 206.26 arc secs.

Rgds,

Jerry.

[DobDobDob (Ron)]

Gee, I was going to buy a green laser 3 or 4 weeks ago then started reading this thread and decided to wait till the dust settled and there was a definitive best buying option for the average bloke who wants it 100% only for pointing at stars during an observing session.

So for $50.00 bucks is the one at Andrews a good buy?

[Ingo]

There are good ones on ebay. "Atlasnova"...they're "Leadlights" and can be modded easily up to 20-30mW.

They're 4.99mW 532nm Green Lasers for about $40USD

[astronut (John)]

Ingo,
You appear to be very knowledgeable about lasers, I hope you can help me.
I have a 20mw laser that works very well hand held, but if I mount it in the Scopestuff mount I have and leave it in the (not very) cold night air the beam vanishes.
A friend of mine has a cheap 5mw laser, mounted on his Scope. He can use it in very cold temps and it fires up instantly with a healthy beam every time.
What's the difference? I use freshly charged AAA NiMh batteries.
Thanks, John.

[Ingo]

Originally Posted by astronut

Ingo,
You appear to be very knowledgeable about lasers, I hope you can help me.
I have a 20mw laser that works very well hand held, but if I mount it in the Scopestuff mount I have and leave it in the (not very) cold night air the beam vanishes.
A friend of mine has a cheap 5mw laser, mounted on his Scope. He can use it in very cold temps and it fires up instantly with a healthy beam every time.
What's the difference? I use freshly charged AAA NiMh batteries.
Thanks, John.

It could be it's a modded one and it's sucking up the batteries really fast because they pull a certian mA. The diode is probably turned up, sucking more juice than it is supposed to.

I'm not saying it is a modded one, but it could be the cold. Cold will shift the wavelengths the diode gives out and the Nd:YVO4 crystals require exactly 808nm. If it's too cold, it wont give out the full output due to efficiency loss and drop in wavelength to maybe 807.7nm which wont lase fully.

[Johnofwa]

Thanks Djvege....
I think I'll take your advice after reading all the info .
What's another $50 or $80 in the context of this hobby ?

[luvlasers]

Its safe to say that you are not going to be hunted down by the police just because you have an overpowered green laser pointer. That is, if you use it in privately and do not use it to cause a disturbance. Its common sense guys, take a 1mW laser pointer outside and shine it on some cops, it'll end you up in jail. Take a 300mW Wicked Lasers Spyder II GX outside on the Meade and shoot the stars, careful with the planes and you'll be alright. I tried that Dragon Site, they paid me to spam the internet, but they screwed me, so I don't suggest them anymore. The most trusted sites are abeland1.com (low powered) and wickedlasers.com (high powered) for green laser pointers.

[Gargoyle_Steve (Steve)]

John another thng that could be affecting yoru laser output is the batteries you are using. rechargables - be they NiCad or NiMH - only put out around 1.2v each whereas any non-rechargable (any that are not flat anyway) put out 1.5v each. So if your laser is like most and uses 2 batteries, you've already robbed it of 0.6v of the 3v supply it's designed to run on - you're trying to run it at 80% power by using rechargables.

Also batteries are affected by the cold too - some batteries will provide way below their "normal" output power when cold. Dewstrap heater for the laser maybe? ;-)

[Ingo]

Originally Posted by luvlasers

Its safe to say that you are not going to be hunted down by the police just because you have an overpowered green laser pointer. That is, if you use it in privately and do not use it to cause a disturbance. Its common sense guys, take a 1mW laser pointer outside and shine it on some cops, it'll end you up in jail. Take a 300mW Wicked Lasers Spyder II GX outside on the Meade and shoot the stars, careful with the planes and you'll be alright. I tried that Dragon Site, they paid me to spam the internet, but they screwed me, so I don't suggest them anymore. The most trusted sites are abeland1.com (low powered) and wickedlasers.com (high powered) for green laser pointers.

Wickedlasers are scammers. Their Spyder's are overpriced, and underpowered. They are also they are certified as 200mW's, not 300mW's like you said in your post. I would not recommend anybody buy from WickedLasers because you will receive a very crappy laser that certainly isn't what you paid for. You can get a 400mW laser from laserglow for cheaper than the Spyder GX's.

Also, if you want a blue one, it's TEM30, not TEM00, so it's 3 beams because their company is too much of a rip off to make it TEM00.

[astronut (John)]

Steve, Steve, Steve, Steve, Steve,
Thankyou!! Your suggestion worked like a charm. Very cold last night and the laser beam fired up each time.

Originally Posted by Gargoyle_Steve

John another thng that could be affecting yoru laser output is the batteries you are using. rechargables - be they NiCad or NiMH - only put out around 1.2v each whereas any non-rechargable (any that are not flat anyway) put out 1.5v each. So if your laser is like most and uses 2 batteries, you've already robbed it of 0.6v of the 3v supply it's designed to run on - you're trying to run it at 80% power by using rechargables.

Also batteries are affected by the cold too - some batteries will provide way below their "normal" output power when cold. Dewstrap heater for the laser maybe? ;-)

[Gargoyle_Steve (Steve)]

You are very welcome John.

[proudy]

Hi All,

I bought a 20mW green laser pointer from Bintel. The first one was a dud - it would would fade very quickly (say after 30 secs) Bintel said its a common problem. The replacement works well all the time (very bright!), but Duracell batteries probably last only about 10-20 mins. So if i use it mainly in momentary mode its fine. I bought it for $129 and consider it ones of my best buys. Fantastic for teaching my kids and others and I've mounted it on my scope which tells me exactly where I am in the sky (I'm a beginner).

[starstruck]

Originally Posted by luvlasers

Its safe to say that you are not going to be hunted down by the police just because you have an overpowered green laser pointer. That is, if you use it in privately and do not use it to cause a disturbance. Its common sense guys, take a 1mW laser pointer outside and shine it on some cops, it'll end you up in jail. Take a 300mW Wicked Lasers Spyder II GX outside on the Meade and shoot the stars, careful with the planes and you'll be alright. I tried that Dragon Site, they paid me to spam the internet, but they screwed me, so I don't suggest them anymore. The most trusted sites are abeland1.com (low powered) and wickedlasers.com (high powered) for green laser pointers.

Originally Posted by Ingo

Wickedlasers are scammers. Their Spyder's are overpriced, and underpowered. They are also they are certified as 200mW's, not 300mW's like you said in your post. I would not recommend anybody buy from WickedLasers because you will receive a very crappy laser that certainly isn't what you paid for. You can get a 400mW laser from laserglow for cheaper than the Spyder GX's.

Also, if you want a blue one, it's TEM30, not TEM00, so it's 3 beams because their company is too much of a rip off to make it TEM00.

Interesting, at the candlepowers forum there is a member with the name luvlasers. He/she has a laser from Dragonlasers and i've read a couple favorable reviews from him/her on Dragonlasers and Laserglow.

Are you the same luvlasers with a sudden change of heart or just a wickedlasers fanboy borrowing the name to flame a competitor.

I would not go as far as Ingo to say that wickedlasers are scammers, most companies have their strengths and weaknesses. I would say though luvlasers or who ever you are that you are scamming. So how about you make a constructive contribution to this thread or find another rock to hide under.

Now back to the thread topic.

Looks like more than 1mW is ilegal in Vic and fine in NSW. What about anywhere else?