Touching the sky

[Coby]

Hello everyone!

I am fairly new to laser (have been lurking for some time but still quite a noob I guess ) and I was wondering how powerful must a green laser be to view the dot on the clouds? I've read before that this is possible.

I currently have a 2W blue laser (bought it from Blord) but because of diffraction(?) the beam goes very wide and I can't see it on the clouds at night. I was able to spot the dot on trees about 1km further (while focused to infinity) but not on clouds.

So, now I want to buy yet another laser (the addiction has begun :drool but this time a green one, and it doesn't have to be nearly as powerful as my 445nm one

So, I found this laser on lazerer:
Focusable 50mw green laser pointer <== Clicky, it's a link!
Will this be strong enough? The site says they are guaranteed overspec so I guess that's good. Or should I stick to a slighty more powerful one from O-like? (Lazerer stock is very... empty right now )

Reading from this forum they both seem good manufacturers and the prices aren't too shabby (for 50mw up to 200mw that is ).

Can you laser-gurus maybe point me in the right direction? Thanks

 

[Bionic-Badger]

I'm not sure about exact numbers, and there probably aren't any because it'll depend on things such as how many particulates are in the air, light pollution, distance to the clouds, etc. At the very least you'll probably need a beam expander to reduce the divergence of the beam otherwise it'll grow too wide (diverge).

 

[weeba2kv]

For all i know you need atleast 2 watt of 532 and depending on how low the clowds are

 

[steve001]

Take a look at this company also, Roithner Laser Technik. They've been in business for a long time.
Laser Diodes

 

[Coby]

For all i know you need atleast 2 watt of 532 and depending on how low the clowds are

That sounds like too much for me right now I've read some reviews on Lazerer that a green 150mw could be seen on low clouds but I guess this is incorrect?

How far can you view the dot from your 400mw green one? And as opposed to your 5mw one?


@BionicBadger: Would a laser with very little mrad value also be good? Or is this extra lense a must?

 

[r1Bro]

A lot has to do with the conditions outside. I've seen my 5mw on clouds before lol low fast moving clouds. I've read places that the range of a true 150mw can be over 10miles. Which would be enough for most clouds.

 

[ZRaffleticket]

I'm able to see my greenie on clouds but only when it's raining

 

[ShortyInCanada]

Just to mess this all up...
On the first weekend of July I went out into the backwoods for a bit of camping and I managed to see my (5mw) red, (5mw) green, and (5mw) purple all on the clouds.
Of courde the cloud layer was only 50 - 75 feet above where I was camping in the mountains so maybe it is a bit of an unfair comparison...
But it does re-inforce the concepts that there are many variables to be taken into consideration.
I'll let you get back to serious discussion again.

 

[Avada Kedavra]

I'm not sure about exact numbers, and there probably aren't any because it'll depend on things such as how many particulates are in the air, light pollution, distance to the clouds, etc. At the very least you'll probably need a beam expander to reduce the divergence of the beam otherwise it'll grow too wide (diverge).

A beam expander narrows/tightens the beam? It should be called a beam narrower or beam focuser then!

 

[Blord]

If you want you can borrow my 300-400mW green to play in the weekend. Providing there is enough clouds in the sky. In the past few days there were not much in the Belgian sky only stars and stripes, oeps

 

[weeba2kv]

How far can you view the dot from your 400mw green one? And as opposed to your 5mw one?

As far as my eyes alow lol

 

[Coby]

If you want you can borrow my 300-400mW green to play in the weekend. Providing there is enough clouds in the sky. In the past few days there were not much in the Belgian sky only stars and stripes, oeps

Thanks for the offer but sadly no clouds this weekend

So if I get this straight, it all depends on how high the clouds are, how much 'particles' are in the air that absorb the laser light and how bright the laser is.

And then I take it that just because green is a lot more visible to the human eye that that one would be the easiest to observe.

That brings us down the question of all questions: Will 150mw be bright enough?

 

[ShortyInCanada]

The only answer that will be valid : Try it and see.
To be more scientific : Try it over several different weeks and see. (Average the results and make a graph.)
If I was a salesman : Sure it will work most of the time. But If it doesn't you can always get a better one and try again.

Hope that answers it.

 

[ElektroFreak]

For all i know you need atleast 2 watt of 532 and depending on how low the clowds are

That's not quite true.. I've been able to touch the clouds with 100mW.. they were low clouds, maybe 100' up, but I could see the spot on the bottom of the clouds very clearly. Even with massive power you still need an overcast day with thick, low clouds.

 

[Coby]

Ok thanks everyone for your input! I will go get a 150mW from Lazerer or from Skylasers.
I've just seen that DJNY has a discount code for a 150mW greenie from skylasers so that's probably going to be the one.

I will try to make a chart with height of clouds (if I can find that info) and visibility of the dot and such

 

[Blord]

Yesterday I pointed the 100mW green to the sky and I saw a clear dot in the clouds.
The weather was a little foggy and the clouds were low and massive.