Looking for specific laser purchasing advice...

[NervousEnergy]

I posted this same topic in the 'buy/sell/trade' forum, but upon reading most of the rest of the current posts that may have been a mistake, as I wasn't making a specific offer.

I hesitated mightily to post, but after researching this forum and all of the linked top-end manufacturer's web sites for several days, I can't find exactly what I'm looking for.

Some background - picked up a very cheap ebay 5mw green several weeks ago, and for the price ($18) I have no complaints at all. I'd like to spend a larger budget, though, to fix it's flaws for the applications I use it for:

- First off, I only need to point, not burn. Never burn. Visible beam at night, and a nice visible dot in full daylight. The 5mw pointer comes pretty close here, actually, but I need the beam to be visible from at least 10' off-center. This is for constellation pointing for my daughter and her friends. The 5mw is only visible if you're standing right next to me. From what I've read here, somewhere between 15-30 mw should be plenty, with probably a top cap of 50mw (correct me if this is wrong.) The daylight dot is working pretty well from the 5mw, and thats for agility training for my Aussie. She responds incredibly well in moving through the course in ad-hoc sequences by putting the dot on the hurdle or hoop she's to go through. Obviously high power here would be very dangerous, so I may have to buy a 5 mw just for this activity.

- Cold weather performance. This is the kicker that's really stumping me. The only laser I've found on the various web sites that even mentions cold weather capability is the Galileo at Laser Glow, and this is the real killer of the cheap $15 green I'm using right now. It's especially surprising to me since so many of these lasers are ostesibly sold as 'astronomy pointers', and even in warm climates the nights get chilly. All the greens I see show an operating range of 15-30C, which is just too warm. I'd buy the galileo in a heart beat if it had a bit more power and a momentary switch.

- Consistency and power. The cheap greenie eats AAAs like my daughter does to popcorn. Anything beefier would be much better... AA, C, CR, etc. Consistent beam output is good, though my problems there likely relate to the cold weather performance problem above, and not really to power. From reading here it sounds like at least a small heatsink is critical to keeping a bright beam for any length of time, which the pens lack.

- Reasonable cost. I can drop $100 on this easily, but the $200-$300 on up most of the true 'portable lasers' cost is a bit outside of my range. Though if the Laser Glow Ares 35 was in stock I might be tempted to grit my teeth and buy it (assuming it will operate in cooler weather.... they don't say.)

Sorry for the information overkill, but I've spent a lot of time researching and come up empty. If anyone knows a unit that comes close to these criteria, including custom makes, please let me know, and they'll have a paypal in minutes. Located in the US, btw, so DX is out.

 

[Razako]

Re: Looking for specific laser purchasing advice..

The cold weather requirement makes it tricky helping you. How cold are you talking about? I don't think any DPSS lasers will work well outside in below freezing conditions. What you'll need to do is keep the laser warm in your pocket and only pull it out when you need it.

The alpha 15 might work for you. With the large head it shouldn't get cold too quickly and it should stay warm enough as long as you keep it running.
http://www.novalasers.com/NOVAstore/pc/viewPrd.asp?idcategory=7&idproduct=36

The X50 would be perfect for star pointing and it puts out 3x the power for the same cost.
http://www.novalasers.com/NOVAstore/pc/viewPrd.asp?idcategory=3&idproduct=84
The downsides=
Takes AAA's
Probably won't do well in the cold
In warm weather you'll be limited to a 100 sec on/10 sec off duty cycle as it lacks a good heatsink.

 

[skylasers.net]

Re: Looking for specific laser purchasing advice..

Hi NervousEnergy, as DPSS green laser pointers do have temperature requirements needed to lasing, it would be difficult to find a green DPSS laser pointer that works well in temperatures well below zero. While most manufacturers like to advertise the range of 10C ~ 30C, green laser pointers shouldn't have any problems at around 0C or 32F. It may take a couple seconds for the laser pointer to warm up. After this initial warm-up period, the laser pointer should be very consistent. A trick would be to leave your laser pointer within the box casing and to leave it in your jacket pocket until you plan on using it. If the temperatures are not too cold, it also works to place your palm around the aperture before and during operation. Hope this helps!

 

[NervousEnergy]

Re: Looking for specific laser purchasing advice..

Ahh, then it's likely just the cheap green pointer instead of a general DPSS issue. I wouldn't expect to use it below freezing, but even here in Texas nighttime temps for the next 4 months when we'll be likely to be out with the scopes will be 2 - 8 C. The simple pointer I'm using now fades badly as soon as temps go below about 10C.

The Alpha 25 looks pretty good, and less expensive than the Ares. Is the beam visible to observers 10' or so away, or will I need to go up to the Alpha 45? Pointing out constellations to a group of kids is much easier if they can all see where the beam is going.

 

[Razako]

Re: Looking for specific laser purchasing advice..

Ahh, then it's likely just the cheap green pointer instead of a general DPSS issue. I wouldn't expect to use it below freezing, but even here in Texas nighttime temps for the next 4 months when we'll be likely to be out with the scopes will be 2 - 8 C. The simple pointer I'm using now fades badly as soon as temps go below about 10C.

The Alpha 25 looks pretty good, and less expensive than the Ares. Is the beam visible to observers 10' or so away, or will I need to go up to the Alpha 45? Pointing out constellations to a group of kids is much easier if they can all see where the beam is going.

The alpha 25 should be enough for star pointing. If you want to be sure then just pay $20 extra for the alpha 45.

 

[dingle]

Re: Looking for specific laser purchasing advice..

I recall a post a long time ago about a stargazer having issues using a pen-style for star pointing. He made a foam insulating tube for it, which allowed the laser to heat itself without the cold sucking all the heat out the second you turn it off. If I remember it was remarkably successful in stopping his night time mode hops and stability issues.

Depending on just how cold your talking about, i'd go with a Nova X. If it's seriously cold, the alpha is much beefier and has more thermal mass, so it should stay warm longer. Plus the shutter in it should help to keep cold air from getting in (just a thought...)

 

[phoenix77]

Re: Looking for specific laser purchasing advice..

You may want to contact scopeguy20. He's an astronomer & uses lasers at night & is familiar with the cold temps. problem. If anybody can help you he can, & he's a great guy, eager to help you & wonderfully kind to talk to rob

 

[NervousEnergy]

Re: Looking for specific laser purchasing advice..

Thanks for that advice. I've been tighly holding the pen laser when operating it and keeping it in an inner pocket when not while pointing at night (temps right around freezing or just under.) That's really harsh on the hands, though, as gloves aren't effective at keeping the laser warm, just my hands. ;-) After 30 minutes of moving the scope around and pointing out targets, hands are blue and laser is pretty feeble.

I keep looking at the buy/sell forum, but all the mid-range lasers for sale ($70-$100) these days from the custom folks seem to be blu-ray builds. I'm tempted by the Ares 35 for sale... if it's still there next week I'll likely grab it. It's tempting to try and build my own from one of the beefier hosts and include some insulation, but even though I'm not bad with an iron I'm a little reticent to try it without a lot more research.