dentist googles are safe??

Just get some goggles from ebay and test yours.
Put on your new goggles, focus your laser for burning, burn some stuff, put your dentist goggles in the beam, if your still able to burn stuff then they're definitely not safe... :crackup:
OF COURSE IM KIDDING
They're goggles made for a specific use, certainly not high powered lasers, you can still do some experiments with them, while properly protecting your eyes.

Además no son tan caros, compra unos chinos tío......

ix551 said:

certainly not high powered lasers

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As of right now, that is true.

Would be nice if someone found a good deal on some that turned out to be like OD3+ performance for 445.

Would OD3+ be safe for 1w laser??
With a good OD could you point direct to your eyes not hurting your self?

Is there any post in the forum where i can read how much OD you need for each mw´s?

Generally, glasses/goggles are *not* meant to protect you if you intentionally shine your laser in your eyes. If you do that, you deserve to go blind. Goggles are just extra insurance against accidental exposure. That said, I don't think any common, cheap goggles will protect your eyes if you take a direct hit to the eye from 1W of 445nm for more than a 1/10th of a second.

Further, in order to be safest, O.D. 4+ is recommended for 445nm, but, if necessary, 3+ would protect you from diffuse reflections (but probably not from a direct hit).

chucho said:

Would OD3+ be safe for 1w laser??
With a good OD could you point direct to your eyes not hurting your self?

Is there any post in the forum where i can read how much OD you need for each mw´s?

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OD3 permits pass through 0.1% and OD4 permits 0.01% of the Laser power, is easy to calculate.

For 1w, OD3 is enough, OD4 is obviously more secure, and would be my choice because then protects you well in the worst case.

But point directly the laser beam to the glasses should never be done anyway.

If someone with an LPM wanted to see how well those 4 I posted perform against a 405 or 445 laser, all of them together with shipping would be less than 30 bucks. After Christmas I WILL be buying a USB Laserbee. Until then I can't be the guinea pig for this

Lotus_Darkrose said:

As of right now, that is true.

Would be nice if someone found a good deal on some that turned out to be like OD3+ performance for 445.

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I actually own a pair that only passes fluorescence, although the design is not so good and I have no way to test it, they don't look very well against 405 too. I also have another pair with almost same design as radiant shades, but they are a little bit weaker, although still seem to have a higher OD than radiant. But I only tested them by my eyes(checked how much light they pass when I shine through them, obviously when not on my face)

I've got a pair of Radiant shades I wouldn't want to sacrifice but I also have some eBay cheapies on the way and a pair from O-Like coming so I may put them up against 1w of 445 and the LaserBee to see what happens.

Beware of goggles you buy anyway, if they are not certified can not be guaranteed safety in the event of a an accidental direct hit of the laser beam.

An example, I have a 50mW green laser and OD3 goggles (in view of the results I doubt it) for this specific wavelength (and not certified), I have set the goggles before my LPM, and theoretically would have pass only 0.05mW for this OD, but pass about 10mW through the goggles.

You can imagine what can happen with a more powerful laser, so it is very important to purchase a specific and good goggles, even if they cost more, because the eyes are priceless.

IMPORTANT: The reading methods may not be exactly as I say, is for reference only, is just to show to the people not point directly the laser beam directly to into the goggles, and more if they are not certified.

Thank you all very much you are making me learn a lot.

Piferal i undertand perfect what you are saying... But if these glases are specialy desing for laser why has to cover all the glases? if you have an accident in a lab normaly will be a reflexion of the laser direct to your eyes:yabbem: and that would be more than laser beam covering all the glasses.
How do they calculate the OD?? Using the laser as a flashing light?

Just like shooting glasses. Should a fragment of the shell come flying at your eye or something, the glasses are there to protect you. They aren't made to point the gun at your eyeball and protect you from the bullet.

piferal said:

But if the laser beam is focused in a very small point, is 10mW what goes through the goggles (for this laser in particular) and in this small point (I have checked it with a LPM), so it is very important do not point the laser directly into the goggles.

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The OD rating of a pair of goggles simply specifies the total attenuation the goggles cause. Therefore if you have a 100mW laser passing through an OD2 rated filter, it will reduce the power to 1mW, regardless of whether you focus it with a magnifying glass to a pin-point or not. However, the what the OD rating does not capture is how long the filter will last under given power levels. The materials themselves may not be able to handle the power levels needed long enough to provide you adequate protection.

That's what certified laser protection (ANSI Z136 or EN 207) eyewear is for: it guarantees that the filter will provide the given OD protection for at least 10 seconds before failing.

chucho said:

Piferal i undertand perfect what you are saying... But if these glases are specialy desing for laser why has to cover all the glases? if you have an accident in a lab normaly will be a reflexion of the laser direct to your eyes:yabbem: and that would be more than laser beam covering all the glasses.
How do they calculate the OD?? Using the laser as a flashing light?

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If you have certified laser eye protection your protection is guaranteed at the stated protection level. However, if you have some goggles that do not have that certification, you will either need to test them out yourself (i.e. certify them yourself), or blindly trust that they'll work.

The OD rating is tested by using a power meter and lasers of known power. The amount of energy detected after passing through the filter determines the OD rating; however, the filter must be able to provide a given level of protection (reduce to < 5mW) for at least 10 seconds before failing to be certified at that OD rating.

^^^Exactly. These goggles are meant to block the right wavelengths, but were not tested against lasers. They could perform great, ok, or horrible. Only way to know is a test. If it turned out that one of those pair tested very well, it may be a cheaper bulk buy to resell.

Bionic-Badger said:

The OD rating of a pair of goggles simply specifies the total attenuation the goggles cause. Therefore if you have a 100mW laser passing through an OD2 rated filter, it will reduce the power to 1mW, regardless of whether you focus it with a magnifying glass to a pin-point or not. However, the what the OD rating does not capture is how long the filter will last under given power levels. The materials themselves may not be able to handle the power levels needed long enough to provide you adequate protection.

That's what certified laser protection (ANSI Z136 or EN 207) eyewear is for: it guarantees that the filter will provide the given OD protection for at least 10 seconds before failing.

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Then my goggles should be far from this certification because is very serious than focusing a laser of 50mW pass up a 10mW, allegedly being OD3.

I encourage all those who have a LMP to check your goggles and check what really filtered, because perhaps are not as protected as they thought.

Just tested both my "expensive" £29 red goggles intended to block 405, 445 and 532nm.

Also tested my £2 B&Q el cheapo yellow goggles.

As expected they both perform the same according to my meter, which measures 2.5mA at 105mA without goggles into the diode and nothing else changed.

With goggles the meter reads 0.03mA which is the same as if the battery is disconnected.


-A

conundrum said:

Just tested both my "expensive" £29 red goggles intended to block 405, 445 and 532nm.

Also tested my £2 B&Q el cheapo yellow goggles.

As expected they both perform the same according to my meter, which measures 2.5mA at 105mA without goggles into the diode and nothing else changed.

With goggles the meter reads 0.03mA which is the same as if the battery is disconnected.


-A

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The problem is that to measure the real power of a laser beam has to be done with a LPM.

With other methods the results can be highly variable and imprecise.