durration of exposure with goggles/glasses

I think certification is even usefull for the laser enthousiast, not just the professionals. An OD is nice, but I've seen glendale glasses (that's a good brand) rated OD 10 @ 1064 and D L4 1064nm.

The ANSI 136.1 standard requires an appropriate OD to meet the MPE, but it does not specify a 10 second or 100 pulses resistance. EN 207 rating will guarantee this. The glasses I mentioned are D L4, that's 10^5W/m^2 for the 315nm-1400nm range. It will withstand this power density for at least 10 second without lowering the protection. For pulses the I, R and M are used instead of the D in the rating.

The difference is that D L4 is good up to a 100mW at 1mm^2, but if you only consider OD 10 you'll feel safe next to a kilowatt laser.

So I think it's good to know what power your glasses can withstand, whether you're a professional or not. With the ever climbing power available to the hobbyists, these things will matter.

Smaller quantities may be certified according to EN 60825. This does not require the destructive testing and thus can't guarantee this stability.

It can be a very steep slope because 400nm and below is probably the absorbtion of the plastic, not the dye in it. Considering the wavelength variation from diode to diode, I wouldn't count on it.

Yes....

Bluefan said:

It can be a very steep slope because 400nm and below is probably the absorbtion of the plastic, not the dye in it. Considering the wavelength variation from diode to diode, I wouldn't count on it.

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Thats very plausible. I think a popular choice for the plastic used is lexan (polycarbonate), which has a very steep drop in light transmisson right around 400 nm.

I have to talk to the guys I know at work that use high powered lasers and see if I can get some stuff from them - but I dont really know them that well and I am not spsopsta be in that building without taking a safety course and I havent so I can only do it when the bosses arent around like holidays and such, lol

I remember seeing a huge sheet of plastic curtain that was orange in color that was like a shower curtain or something like that and it was hanging up in a place where a laser was working that was controlled by a robot arm, the sign said it was a "351.1nm-528.7nm max output 6.7W FBG #2" - in large numbers written in a black marker in the corner of the curtain was written 465.8nm, and there were 10 more curtains bunched up on another pole on the wall behind the spool of cable, I say that one said "454.6nm" written in black marker on the corner of it so I assume it was running at 465.8nm at the time since that curtian was up then (there were coincidentally 4 other rooms that said FBG#1,3,4,& 5 on them also so I assume this was just the machine number?) and there was a large spool of fiber optic cable feeding into it that was getting hit by the laser in pulses as it moved and was re-spun up on the other side of the curtain - like a huge 10x20ft curtain covering a 3 walled room with the curtain covering the 4th wall which was open and 2 large spools outside next to the wall on either side of the room feeding and eating fiber optic cable - it was bare fiber optic cable like the stuff you get in kids toys and holiday decorations that different colors come through but it was thicker looking - there was an end hanging loose in the spool that was the end of the roll that I could see sticking out from the spool

I guess if it can protect you from a laser that powerful and in a wavelength so close to 445nm couldnt I make something out of it to use the laser without glasses, this thing was like 10x20ft and hung by large rings over a pole like a shower curtain would be but huge - maybe get an old one that had holes in it or something like that from folding it up a lot this one was showing wear

I think it was an argon laser but I have no idea what it was doing, he remarked it was the FBG machine whatever that is?

? making fiber bragg grating inside the fibers, changing the refractive index with high power pulses ?

(just trying to guess ..... cause they use sometimes frequency doubled Argon lasers, for this .....)

leftkidney said:

"Utilizing non-reflective technology, energy is absorbed for a minimum of 10 seconds at the maximum power density for the OD or L rating before loss of protection and will not photo-bleach or degrade over time."

so 10 seconds min, but what about the maximum? like getting a radiation suite and having it say it will protect you for a minimum if 10 minutes, so what after 11 minutes you have problems

what about taking 2 pairs of these, like the glasses and goggles and wearing both of them, would it double the protection? - or should I just cover them up after 30 seconds or so to let them recover like my "laser dudes" do?

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You are misunderstanding what the quote on their website means. From what I can gather, you thought it means that you can only use these goggles for 10 seconds at a time before you need to let them "recover", correct?

What the quote from their website actually means is that these goggles were subjected to direct beam radiation at whatever power level they are designed for, and survived for 10 consecutive seconds with no bleaching, or dangerous energy breaches to the other side. This is analogous to pointing the laser at your eye and holding it there for 10 seconds, not simply being exposed to indirect light from burning.

just got the glasses from OEM and they say on the paper it came with that its a maximum of 10 seconds exposure - but nothing about what happens after that

I assume this is meaning a direct beam onto the lens not a reflection but I think that there needs to be some clear info about what happens when you look at the beam as its focused and burning something or a reflection like that

furthermore I know people have noticed this one I have read about it in the forums before

when you burn something with a red laser you get a bright blue or white spot, I have been told that this can damage your eyes as a arc welder can unless you are using full spectrum glasses, if you are using a red laser and are using the blue glasses and you see a really bright blue/white light it will pass through the glasses for sure, and I dont know if its as bright as a laser beam or what - you know how laser light gets treated differently by your retina and focused into a single small spot unlike normal bright light, well what about this is this just a normal bright light that is caused by the vibraton of the smoke particles or is this laser light that is blue/white? doughtful its laser light but I dont know - I know some laser guys but I havent been able to talk to them in weeks so I cant ask them


lastly I got the glasses and they are the ones for for the 445 lasers that are orange in color, but it says it protects up to 532nm which is green but when I put them on my blue led's are either not vissable or a faint green color, but the green led's are still just as green - when I use my blue glasses for red lasers and look at a red led I can only see it faintly - yea I know these are led's not lasers but they are sosposta block light of a certian color and I assume that the green led's are close to 532nm like a green laser but not sure, and since they say up to 532nm and most lasers are +/-5%nm is this really good for green lasers, I know that the normal green laser glasses are red not orangeish like these are so what?

The 10 second exposure is for direct or specular reflection. You would have to hold your head in the beam for 10 seconds in the same spot at 10cm from the aperture. They will work without problem for normal operational use and diffuse reflection indefinitely.

Your green LEDs are >532nm. The ARG response curve drops off very rapidly after 532nm.

Here is the common LED chart:

570nm Super Lime Green 2.0 1000mcd @20mA 15° InGaAIP - Indium Gallium Aluminum Phosphide
565nm High Efficiency Green 2.1 200mcd @20mA 15° GaP/GaP - Gallium Phosphide/Gallium Phosphide
560nm Super Pure Green 2.1 350mcd @20mA 15° InGaAIP - Indium Gallium Aluminum Phosphide
555nm Pure Green 2.1 80mcd @20mA 15° GaP/GaP - Gallium Phosphide/ Gallium

The color of the filter is a result of the dyes used in the polycarbonate. The filter color is not a good way to identify the wavelengths they are protective against. The YLW filter will protect against 445nm but is a very light yellowish green. The orange filter ARG protects against 445nm as well as the AL2 and AL3 red colored filter. We have YAG filters that protect against 1064nm, 808nm and 532nm that are green or brown in color.

well I just assume the led's were around 532nm but probably not now that I think about it

but the color not being a good way to identify the wavelength they protect from? is that for lasers that are not 532,445,680? as in complementary colors

because I assume that those lasers would need the complementary colors corresponding to them to protect from them, as in red (blue or cyan color), green (magenta color), blue (yellow color) (but it could be red is green, green is red, and blue is orange) being the primary colors would only need a color that will cancel out the color of the beam but other colors outside of that wavelength would need a mixture of colors and depending on the color to protect from it could maybe be 2 colors (?depending on which one is the dominate one could tell which one would have a higher OD rating for what color, as in the YAG filters that protect against 1064nm, 808nm and 532nm that are green or brown in color is it that the green one has a higher OD for one color like say 1064 and the brown one has a higher OD for another color like say 808 or 532?) for the same wavelength since a mixture of colors using "subtractive color reproduction" (that is a printed color versus a color produced by a light that would be "additive color reproduction") being 2 or more colors mixed together in a physical form to reproduce something that "must have a light source to be viewed" as apposed to something that produces a light source to be viewed

you know how a monitor is "additive color reproduction" where as a printed picture of the same thing would be "subtractive color reproduction" as in the monitor is adding colors to make you see them and the printed thingie is reflecting/absorbing colors to make you see the correct color if viewed in the correct light of D6500K

I assume these are correct terms but I never looked them up to see if they exist so additive and subtractive color reproduction might be a term that I made up and there is a real term that is describing the same thing that I dont know what its called but you should know what I am talking about





thanks for the glasses, the only problem I have found is (I ordered the style 35 wrap around ones) and I can see light reflecting off my nose and getting past the glasses, I have to get some kinda nose pad or something to put on them to prevent this when I get my laser, because I can wear them and see everything in orangeish color but see normal light leak through the nose part - wonder if the laser can reflect off my nose and hurt my eyes?, probably can - oh, yea, and the neck cord was imposable to get onto the end of the arms I had to open it up with a screwdriver and stretch it out first then it sorta fit (sorta like my high school girlfriend, lol)

but the glasses are really good quality construction I am impressed - I dont have a small head but I have the arms all the way in, someone who would need them extended must have a really long face or whatever because when I put them like that they are like 3 inches from my face, lol


also the glasses are good for 532nm green lasers correct? - if so you also said that they drop off sharply after 532nm so how far after that? - I think that red lasers say 650-680nm or 650nm +/- 5-10nm or something like that, so are green 532nm lasers since they are DPSS (mostly) all 532nm exactly or within 5nm or less - I mean could i have a green laser that was like 540 or 550nm and still look green to me? or since its a DPSS will it be exact?

Just to make it more complicated: ML7 glasses are green, but do protect from 532nm green lasers. Because your eyes have a limited resolution in the color spectrum printers can get away with just 3 colors. With laser safety eyewear you really have to know what it's rated and certified for. Because absorbtion can be very wavelength specific the color appearance of the glasses does not indicate what wavelengths it attenuates at what rate.

DPSS lasers are far more stable in wavelength than diode lasers, so a green laser will be 532nm with much less than 1nm uncertainty. Gas lasers are even more precise.

leftkidney said:

also the glasses are good for 532nm green lasers correct? - if so you also said that they drop off sharply after 532nm so how far after that? - I think that red lasers say 650-680nm or 650nm +/- 5-10nm or something like that, so are green 532nm lasers since they are DPSS (mostly) all 532nm exactly or within 5nm or less - I mean could i have a green laser that was like 540 or 550nm and still look green to me? or since its a DPSS will it be exact?

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I cannot say what you will see after 532nm because the filters are protective up to and including 532nm and color perception is subjective. As mentioned 532nm DPSS has a FWHM of +/-1nm. Anything beyond that can pass the filter based on the response curve with more and more visible as the wavelength lengthens out to about 580nm. Keep in mind, the certification is to 532nm inclusive, so they are not laser protective beyond that.

so if I wanted glasses to use for a 3 color laser build red green blue would they be brown or black tinted - because it will be a "white" laser if the beams are combined correctly so would you use something like welding goggles

I have seen some but never got to look up close, they looked brown or black tinted from afar and there was like 20 different glasses in wooden boxes like mail slots in an office and there were the ratings and other stuff on labels on the boxes - one said 200nm-2000nm protection

leftkidney said:

well I just assume the led's were around 532nm but probably not now that I think about it

but the color not being a good way to identify the wavelength they protect from? is that for lasers that are not 532,445,680? as in complementary colors

because I assume that those lasers would need the complementary colors corresponding to them to protect from them, ...

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"Primary" and "complementary" colors are simply an illusion of your brain, brought on by the fact that your eyes' cones (the color sensitive photoreceptors) detect colors in red, green, and blue. It's the same way digital cameras work, whereby colors are separated into red/blue/green components, and when combined they appear to have colors in between.

The use of three colors can lead to illusions of some color because receptors with "non-adjacent" spectral bands may be excited at the same time. For example, while there is a "yellow" color with an actual wavelength between green and red (which are "adjacent"), when your eyes are stimulated by light that affects the red and blue receptors, it results in magenta--a false color that has no actual wavelength because the components are at opposite ends of the the visible spectrum (green's band is between them). Magenta is just your brain's way of making sense of combining red and blue.

So don't rely on what you see as a "general rule" for determining what protects you or what does not. Look at the protection graphs and the certifications to see what is actually protected, and what is not. Some goggles may even be "deceptive" , such as the ML7 that was mentioned earlier, which has a greenish tint, and yet protects against 532nm (green) light.

well having glasses that are the same color as the light they are protecting from would be good if it allowed you to see the laser better

I got one of those laser levels - it says 0.95mW - and it came with a pair of red glasses to allow you to better see the dot when in a brightly lit room or outside in direct sunlight, they work great and I can even see the beam of this really low powered laser when its darker in the room - also the laser is being split into 5 different beams so go 5 different places, so thats like 0.12mw each if it works like that and I can still see it fine with these glasses on

however if I use a 100mw red laser its as if its a 1w red laser, I can see the beam in direct sunlight - I know its dangerous to do this so I have never done it more then 2 times and only looked at the beam not the termination point so its probably fine since you can look at the beams with no protection and have no problems, its the reflections that cause problems from what I know


speaking about reflections, I have light reflect off my nose and into my eyes when wearing the glasses I have (check earlier post) I dont ahve my laser yet so its not a problem I dont think but being a nerd who stays indoors all the time, and a white person I assume it will reflect a lot so I will be looking into some kinda nose pad of something to protect me