Are goggles necessary for the sanwu blue 304

[Garuda]

It says it can focus and burn or does it recommend goggles just in case you hit something shiny or reflective

 

[RedCowboy]

Anytime you use a laser over 5mw where there's any chance of a specular reflection you need to wear laser safety glasses designed to attenuate the wavelength you are lasing with, now diffuse reflections are not a problem as long as you are at least a meter or more away but that's the minimum, I typically don't like to look at the lasers spot ( termination ) on a non reflective surface any closer than about 3 meters and only for a quick glance if it's a powerful laser to avoid after images.

So if you are working at arms length, say on your desktop, then you should be wearing laser safety glasses.

If you are terminating your laser over 5mw onto a non reflective surface across a room, then you can look at it as long as the situation you have created is safe.

When in doubt, wear the safety glasses, because mistakes do happen in an instance when you least expect it.

 

[paul1598419]

Remember that you won't be able to see the laser's beam with goggles on. I rarely wear them when I fell sure that specular reflections are not possible. This would be against any wood surface painted or not. And I have looked at diffused reflections at far less than a meter without any damage to my eyes. But, that's me and you should do what you feel is necessary to protect yourself.

 

[RedCowboy]

The fact is that the strength of the laser in question matters, you shouldn't look at the spot on the wall from a 10w argon laser any closer than 3 meters according to the University of Chicago Radiation Safety Office, but most new hobbyist here are buying the 1-7w blue lasers and the distance according to what I read was 1 meter for diffuse reflections because a diffuse reflection can cause eye damage and what someone got away with is not a good rule of thumb.

Calculating MPE and NHZ

 

[Encap]

Sanwu 445nm blue lasers are available with output powers of 150mW, 1600mW, and 3000mW.
https://www.sanwulasers.com/product/304blue They are not less than 5mW and not toys. They can causeause 0ccular damage in less than 0.25 seconds. Get and use a good pair of laser goggles.
See: https://www.survivallaser.com/browse/cat556089_826120.aspx

Avoid becoming an accident looking for a place to happen. Get a good pair of laser safety goggle
It is more than a good idea to look at and study the following authoritative laser hazard web sites:
Laser pointer safety
https://www.laserpointersafety.com/
Laser safety facts
https://www.lasersafetyfacts.com/classes-menu.html
Laser hazard chart
https://www.lasersafetyfacts.com/resources/FAA---visible-laser-hazard-calcs-for-LSF-v02.png

Also have a look at what happened to one experienced member in less than 1 second while using a 1000mW 445nm laser. See thread: https://laserpointerforums.com/threads/hit-in-eye-with-1000mw-445nm-blue-laser.69469/

 

[paul1598419]

Measuring laser power with a meter often requires one to be within a meter to effectively measure its power. This was particularly what I was talking about. The surface of the device is black and the amount of diffused light is not as much as it would be off a white painted wall. I have used lasers over 3 watts to burn unpainted wood often, though not recently and within a meter and do not even get discomfort.

 

[RedCowboy]

You can glance the sun and get away with it, but don't stare at the sun or blind you will become.

You can pass your hand through the flame of a blow torch and no damage is done, slow your hand as you pass it through and feel some heat, slow down just a little too much and you will get a nasty burn ( damage ) ...... in time your hand will heal, your retinas..... no so much.

Your eye's will usually recover from temporary flash blindness, for instance when you are driving with the sun reflecting off of a chrome bumper in front of you until you pass the car and you have after images for a minute or two that dissipate.

Weld with the wrong filter and I have had after images that last for hours, but had I not been wearing the mask at all, then permanent damage would have been done.

Yes you can glance the termination of a 5W blue laser on a block of wood or an LPM sensor at 18 inches and probably get away with it many times, but familiarity breeds contempt that leads to pushing further and further until one notices spots long after the looking is done, hopefully they go away but there is no guarantee, so the recommendation based on what I have read and many years of personal experience is 1 meter for glancing the spot/termination of a multi watt lasers on a non reflective surface and 3 meters for taking a little bit longer look ( a few seconds ), but I would not sit and stare at either and if my job was testing lasers all day long I would do it wearing protective glasses.

The bottom line is don't take chances with things you are not willing to lose !

 

[paul1598419]

I would never even try to glance at the sun. That is a recipe for blindness. It happens to people all the time in the shadow of a solar eclipse that watch it without protective eye wear. It really depends on the wavelength and the output power of the laser how long at at what distance I observe diffused reflections. Most of the time I spent burning wood was with 445nm and 450nm lasers. They are far less objectionable than high power green ones. You do you and I'll do me.

 

[RedCowboy]

You can do you, but don't discourage new members from taking our very reasonable safety advise, or you can do you elsewhere.

 

[paul1598419]

Really?! When did you become the law here? Nothing I posted was out of line with good practices.

 

[RedCowboy]

And I have looked at diffused reflections at far less than a meter without any damage to my eyes.

The reason a multi watt blue laser seems less objectionable to you than a green laser is because our eyes are more sensitive to green light, but you will damage your eyes with too much blue light especially because it doesn't look as bright, that's yet another reason to wear the laser safety glasses.

You are suggesting to readers that it's ok to burn with a 3w laser at " far less than a meter " without wearing any laser safety glasses.
That is out of line with good safety practices.
Good safety practices are wearing laser safety glasses when burning things at " far less than a meter " which is presumably desktop distance.
People will think it's ok to do this all day long, it's not.

 

[paul1598419]

Most of my use at close range was to measure the output power with one of my meters. The black finish on all these sensors make levels of diffused laser light quite low. It is not an easy task to measure laser's power with OD4 or 5 goggles on as the entire light needs to be on the sensor.

 

[RedCowboy]

If people set up their LPM in a safe location where their backstop isn't covered with anything reflective, then seated at an angle to the sensor face, place the laser close to the head, turn it on and pull slowly back to keep the laser aimed onto the sensor, then they can conduct a test without ever seeing the spot/termination as long as they work from an angle so that the edges of the sensor body blocks their view of the termination on the sensor surface, but even if the spot is glimpsed it will be mostly absorbed and the laser should be unfocused for the test as well, so if done correctly then people can do a LPM test without laser safety glasses but you can do the test while wearing laser safety glasses by starting close and slowly pulling back.

However we ( you ) were talking about burning wood with a 3w blue laser at " far less than a meter " without wearing any laser safety glasses, there is no reason to do that and every reason not to burn up close without safety glasses, actually you can see what you are doing better with the laser safety glasses as without them all you can see is a blinding bright spot that hides all the fine details.

 

[paul1598419]

One can easily see the burning of wood without safety goggles. I've done it many times and nothing is lost. On unpainted wood the diffused reflection is not that bright especially using blue lasers. However, you need to see the sensor surface when measuring the power. The diffused reflection, even with high power green lasers isn't that bright.

 

[RedCowboy]

Nonsense, I have done wood burning art with a multi watt blue laser and wearing my laser safety glasses allows me to MUCH BETTER see what I am drawing, without the glasses the bright blue spot drowns out all the fine detail.

When burning wood with a multi watt laser closer than 1 meter a person should be wearing laser safety glasses to attenuate the wavelength they are lasing with, not only to protect their eyes, but to allow them to better see what they are doing.

 

[Unown (WILD)]

One can easily see the burning of wood without safety goggles. I've done it many times and nothing is lost. On unpainted wood the diffused reflection is not that bright especially using blue lasers. However, you need to see the sensor surface when measuring the power. The diffused reflection, even with high power green lasers isn't that bright.

You're not getting it. LPF has to have a higher standard on laser safety otherwise you can get a lot of angry people itching for a lawsuit or worse someone losing their sight. People come here for guidance and information. If you're going to open your mouth make sure it doesn't subject LPF to a situation we don't want.
I know it sounds strict but everything involved with safety has to be because it means loss of QOL and death.