laser safety questions and also comments on my DX 30mw unit

[FloridaGuy]

I purchased a DX 30mw laser that arrived a few days ago. Having never seen one of these green babies work before, I was shocked at how far the beam would project. The beam was very very obvious and bright on the non-window side of a building about 3/4 mile away (at night, of course). We then discovered that we could hit the water tower that is located about three crow-flyin' miles away. That was really shocking to us. From our vantage point, the beam on the tower was not bright, but I wonder what it would have looked like if you were at the base of the tower looking up. This was with the cheapo batteries that came with the laser. I think the order took about three weeks to arrive from DX. Overall, I was very impressed with the product.

Now for questions. . . I am a frequent reader of the LED forum here at CPF, but only tonight noticed this laser forum and I'm reading things here that concern me. First, the IR issue. I have been very careful to not shine this thing in anyone's eyes. That only seems like common sense. Is there IR danger if you are not looking into the beam? Also, I'm confused about whether they have the discussed IR filters or not. Do some units have and some do not? How can you know about the IR level of a given laser? I have three young children and I wan't to be very careful with them and myself. I sure hope that I didn't do anything that would have hurt their eyes when trying this thing out.

I see references to NewWish lasers. Is that another brand or a generic term refering to all these (new?) green lasers?

Now for the legality questions. I didn't realize that these were not technically legal here in the USA. Is that indeed correct? If so, what are the ramifications of using these in public, as long as you are not actually shining it at someone? Is there danger to someone located, say, 1/2 mile away that happens to get in front of the beam? Will it seem intense to them from a distance? I've read about people shining these illegally into airplanes and I can understand that. I just don't see how someone could hold it steady enough to actually "track" a moving airplane as opposed to occasionally hitting one as you pan back and forth across the sky.

Thanks so much for any "light" that you can shed on these questions.

FloridaGuy

 

[Kenom]

Ok so to save you time in searching the forum and finding the information as most others will make you do when your new (there's nothing more tedious than repeating old information) I will step up to the plate and tell you the basics about your new DX 30mw extreme. I've got 2 younguns myself and was concerned when I purchased my first 30mw unit.
To aleviate your fears on dx's website anything below a 50mw unit is going to be filtered for IR. They are actually Newwish lasers being sold from DX. If you do a search in this forum you will find lots of information about this particular laser.
The fact that you could hit a water tower 3 miles away is pretty impressive. I've got the same thing and it's not capable of going that far.
The newwish 30mw has an APC (it's a sensor located up top and splits the beam to the sensor and monitors the output to limit to a certain power level) keeps it at under 30mw. I've got a post of the guts if you want to see them.

http://www.candlepowerforums.com/vb/showthread.php?t=164105

Legality issue. It is illegal to own anything over 5mw that does not have modifications to the unit for safety reasons. A key on the back so there is no accidental activation. A shutter so even if it's accidentally activated no light escapes the front and other special modifications to the laser itself. You can get in trouble if the laser is accidentally shined into someone's eyes and is blinded but I do not know what the consequences of said action would be.

I hope I've answered your questions. If not post more and I'll muddle my way through

 

[FloridaGuy]

Ok so to save you time in searching the forum and finding the information as most others will make you do when your new (there's nothing more tedious than repeating old information)

Actually, I did search the laser forum and read several threads through completelyl. When I was done I still had the questions that I posted. I guess I didn't search long enough. It was confusing when some people said that these lasers were dangerous and some said not. DX was quoted as saying that the lasers didn't have filters but others said that they did, and so on. I saw references to "newwish" but didn't catch that that was actually the ones DX was selling.

OK, so these are not dangerous then. For lasers that are potentially damaging to the eyes, is that only when a person is hit head on with it, or is is somehow dangerous to be in the presense of the laser or to see the beam in the sky or to have it reflected off of a wall and back to you? I can't imagine the anguish that I would feel knowing that I had ever damaged my eyes or the eyes of someone else - but apparently it is not an issue with this laser.

Thanks so much for your reply Kenom.

FloridaGuy

 

[Aseras]

you do not want direct contact with the beam or a reflected beam with your eye. a diffuse ( scattered reflection like on a rough surface ) is "safe" as long as you are not too close to it. reflections sneak up on you, and just toying around and hitting the right thing can throw a dangerous reflection into your face/eyes. you also have to be aware of who else is around or could walk in while you are playing... with a 50mw or less it's reasonably safe as long as you are creful what you relfect off of, avoid highly reflective surfaces up close and control the environment. Just never shine it at people or animals.

 

[Kenom]

and it can be just as damaging to shine it into the side of your eye. periphreal and all that. once that amount of light hits your eye regardless of it directly hitting the back of your eye damage can be done. Also don't look at the beam hitting off of surfaces too long. You will notice a tendency to want to look away yet your fascination keeps you from looking away. Your eye is just not designed to look at that kind of light for long periods of time.

 

[flashlightpoor]

OK, so these are not dangerous then. For lasers that are potentially damaging to the eyes, is that only when a person is hit head on with it, or is is somehow dangerous to be in the presense of the laser or to see the beam in the sky or to have it reflected off of a wall and back to you? I can't imagine the anguish that I would feel knowing that I had ever damaged my eyes or the eyes of someone else - but apparently it is not an issue with this laser.

Thanks so much for your reply Kenom.

FloridaGuy

No, that laser is definitely poentially damaging. I am still waiting for my 30mw from DX, so I don't know the actual power out, but as a reference in my lab we use laser goggles when using anything over 10mw. Even powers lower than 10mw can cause damage, especially if you are exposed for a long period of time, we are talking seconds not minutes. The safest thing to do is to wear goggles, but you are not going to do that because then you can't see the laser. Assuming you aren't shining a laser directly at people the biggest threat is from reflections. Be cognizant of any potential reflective surfaces that can bounce the beam back at you or at someone else. In my lab all of our tools are black anodized and we take off all jewlery, watches, belt buckles etc- anything that can reflect a beam. If someone drops a tool in the beam path it won't throw reflections all around the room.

You no doubt have also seen mention of IR radiation on this forum. The issue with the IR is that it is invisible to the eye. if the IR light is bouncing off of something you won't be able to see or avoid it.

the fact that lasers above 5mw require special licensing isn't arbitrary-- be careful.