Quick laser safety question

[Bronco]

I've owned a 5mw green Jasper Curve laser pointer for several years now and have been very impressed with its reliability and quality of construction. It just works every time I push the button which is a nice improvement over other more expensive brands that I've owned in the past. I see where the Jasper folks are now selling more powerful modules. I've avoided these in the past, partly due to the expense, but mainly because of the safety considerations. One set of eyes is pretty much all you get in this life, and I've been very reluctant to put myself in a position where I could possibly be responsible for permanently injuring someone's eyesight (or my own for that matter ).

At the same time, I have a vacation to Lake Mead coming up, and I notice that the moon will be a new (i.e. not illuminated) the week we are there. I can only imagine how impressive a Jasper 50mw green laser would look in such dark conditions. But before even considering such a purchase, I'd like to know a little more about the safety guidelines for a laser of this strength, particularly with respect to bounceback. Would shining it at a white wall ten or fifteen feet away in darkness be dangerous? What about shining it down onto the calm surface of the lake at night?

 

[Bimmerboy]

Hi Bill,

50mW of green will look great in even sub-par quality darkness, but is easily enough power at close range to "put someone's eye out" much faster than than the blink reflex can protect it. How close is close range? That somewhat depends on the laser you get, i.e. how well collimated the beam is, if the power rating is true (and not just a bunch of IR boosting the number), etc., but it doesn't really matter. My rule of thumb in handling a class IIIb laser is to respect it, and use the same level of safety and awareness as if it were a firearm... one that can also shoot back at you if you hit a reflective surface!

As a side note, IR (infrared) is difficult to focus, so even if you have zero filtering, the distance at which damage to the eye occurs is far less than the collimated beam, but still potentially dangerous to those standing next, or close to you if you're not careful. Anyway, on to your questions...

A white wall is going to give you a diffuse reflection, but nonetheless, 50mW at 10 - 15 ft. isn't advised. At best, it's going to be bright as all hell for anyone looking at it, causing a nice spot in the vision for a while, but the risk could be higher than that. If the paint is semi-gloss, forget it. Do NOT hit any windows, or mirrors as you could wind up with a much bigger problem. I don't even feel comfortable with my 38mW in larger rooms.

As for bouncing off a lake, I haven't tried it myself, but sounds like it could be a pretty cool effect. Just be aware of reflection angles, and what's going to be at the end of the beam. Angle it so the beam reflects skyward. I'm sure we're talking distances at which there is no safety risk, but a direct flash will still appear quite bright at long distance. I have no idea of the effect on other animals, but it probably looks bright to them as well... lol.

I'd say get a decent quality unit, have fun with it, and just remember that like any adult toy, it comes with Mom's warning.

 

[allthatwhichis]

Only do what you feel safe doing, but, just for perspective; I look at the 1 Watt dot of my Kvant RGB projector hitting my off white wall, 10 feet from the projector all the time. Treat it like the Sun; don't stare at it and make sure you and the ones with you are mostly responsible and you should be fine with powers well over 50mW. Don't point it ay anything highly reflective... and be aware of reflection angles. Matbe een grab some goggles and practice "playing" with it in a room by yourself. Playing with one of these will only make you go blind if you are playing with it "wrong".

 

[bshanahan14rulz]

This thread reminded me of somewhere on this forum where I saw someone posting their experience with buying a laser off of a china direct site. Ended up getting a dildo in the mail instead of the expected laser. anyhoo...

 

[Bronco]

Thanks, guys for sharing your knowledge and insight. I'm very much on board with the notion of treating a 50mW greenie as if it were a loaded weapon. The idea of accidentally hitting something overly reflective is what really scares me. But you have given me some idea as to what are good safety parameters and I thank you for that.

 

[The_LED_Museum]

At shallow angles, water has a reflectance approaching that of a mirror, so you do need to know what (or who) is downrange and be certain that you do not accidentally hose it/them down with your reflected laser beam.

 

[Bronco]

Understood and thanks for the tip. One nice thing about desert lake camping is the ability to steer far clear of other campers. But it's a good thing to keep in mind nonetheless.

For the record, and based on some research done in this forum, I decided to go instead with a Laserglow Aries-50. The shipping fees that Laserglow charges aren't inconsequential, but I have to give them credit. I placed my order with them on Friday afternoon and they had their international, transcontinental shipment on my doorstep Monday afternoon.

As for the unit itself, it's even more impressive. Yes, the number of steps that must be followed to light-off an Aries-50 is only slighly less than those required for a Space Shuttle launch, but I'm thrilled with that situation. Even the way the batteries must be loaded in backwards is a welcome safety feature. I can't wait to see what this thing can do on a cloudless, moonless night out in the middle of nowhere.