Advice needed: Looking for an astronomy laser

Hello forum!

I would like to buy a 532nm green laser pointer for astronomy purposes. It will be used by hobby astronomers at our local observatory for guided stargazing events with groups of up to 20 persons. The laser will be handled by professional laser experts only.

These are the specs I have in mind:


IMPORTANT:
- The beam must be clearly visible at night for people standing some 10-20 feet off the beam line. On the other hand, it must not be too bright, so that faint stars are not outshined. According to this review an output power of 20-50mW seems reasonable to me.

- pen-style or very small host like Laserglow's Galileo model

- stable beam: small effect of temperature change on brightness, no TEM mode jumps

- operation in a winter night should be possible (-> min. operating temperature)

- quality product, no cheap plastic toy

- price < 100$ / 75€

- shipment to germany


LESS IMPORTANT:
- TEM00
- type of battery
- IR filter


UNIMPORTANT:
- on/off click switch (In fact, I think I'd prefer a momentary switch on the side.)
- adjustable focus
- waterproof


NOT SURE IF IMPORTANT:
- beam divergence and diameter
- duty cycle: on-time not shorter than 60s? better: no duty cycle at all?


I've already found products labelled 'astronomy laser' or similar, like the Galileo or the corresponding models at DragonLasers. But they are all class IIIa lasers, and I'm afraid that a 5mW beam wouldn't be bright enough for a person standing 10 feet away under disadvantageous conditions (dry air, light pollution, dusk time).

Does anyone know a product that matches my description?
Should I scale down my specifications?
How important are divergence and duty cycle for a star pointer?

Take a look at Optotronics pointers. They are high quality and Jack is very prompt answering your questions. 30-50mW should fit the intended purpose. If you get a pointer much brighter, it will affect your night vision when attempting to point out very dim stars. I personally use the Optotronics Premium +40mW Green Laser. Good luck.

Check out the Astronomers Social Group.

I suggest the Viper series from Dragonlasers. They are made by CNI, IIRC, which make the best quality lasers out there.

Green Laser Pointer ----- 532nm Laser ----- Viper Series Lasers :: Handheld Lasers :: Dragon Lasers

Both the 35mW and 55mW are in your price range and it just depends on how bright you want the beam. For that many people, I would suggest the 55mW but they will both be visible.

Thanks for your recommendations! Maybe the 35mW Viper would be the right one for me. If there's a GB going on for CNI lasers right now, it would be nice, if someone could post the link. I didn't find a GB thread using the search tool.
Does the 35mW Viper run on a duty cycle?

There isn't a CNI GB going on right now that is open...sorry! I don't see a duty cycle on the Viper, so I don't know what to recommend. I'm sure someone will have some insight on it.

I'm not so experienced with high quality pen-style pointers. I though that they would turn off automatically after some 60 or 90 seconds of contiuous operation to keep the IR laser diode from being damaged. But I guess it's not that important, because noone will point at a star for longer than a minute ...

I would suggest this one from GearXS:
True 100MW (532nm) High Powered Deluxe Laser Pointer - Green

I had one, but sold it to another member of our astronomy club. I measured consistent 80+ mW output, should be perfect for what you are doing. $30 including shipping to US, not sure about shipping to Germany.

For the size group your are talking about I agree around 50 mW or so is all you'd need. For the large groups we get in Yosemite we need something brighter but that's another story.

William

To join the LPF astronomy social group, click the community tap at the top of the page.
then click the social group tab and join the astronomy group. Post photos of your scope and astronomy club. There are lots of other social groups you might want to join too>

Thanks for the invitation to your group, elite ares and Petacat! I just joined and uploaded some pics of my scopes. Hopefully, I'll soon find the time to write a short hello message to the discussions board.

@wbp
Thank you for the link. 80+ mW seems a little bit too much to me. Usually our groups at the observatory have about 10 persons.

@all
Did anyone ever have trouble with a DragonLasers shipment to Germany?




UPDATE:
This week I made my order at DragonLasers. At first, I couldn't decide whether to buy the 35 mW or the 50 mW Viper... So I just ordered both of them ! When the pointers arrive, I will see which one is better for star pointing, and the other one will be sold to a friend of mine.