A Plea for EYE Safety!!

[Solonar]

I remember similar photos, when I took a Laser Safety course at USC. I was working with a 150W Co2 and High powered pulsed Nd:YAG.

 

[Xer0]

Im wondering, if looking into the real projector at a presentation could fry your retina too.
It's still 12W of Lazor coming out, even if unfocused...

 

[ElektroFreak]

It's not actually 12W exiting the aperture. There are lots of optical losses, and the light is passed through a diffuser also.. between that and the extremely high divergence of the projected light I would imagine that it's not any more dangerous than most high-intensity non-coherent light sources.

 

[MERC]

I always respect safety when it comes to lasers but calling Casio to complain is ridiculous. We have a name for people like you in the firearm community its fudd, you would throw the rest of the laser hobbyists under the bus as long as your niche was unharmed.

I realize ill be flamed pretty hard but I have a strong opinion on things like these.

 

[ElektroFreak]

You won't be getting flamed by me..

 

[LSRFAQ]

How about following FAA guidelines to make your decision to use a laser outdoors?

Evaluate if your within 5-7 miles of a Airport. If you are, keep it out of airspace, if its more then a few milliwatts.
Nice simple rule... Based on FAA's own rules for outdoor use of lasers.

Find a FAA "sectional" chart on line for your area, example,

Here is a partial FAA sectional for LA:

AeroPlanner.com

Here is another source:

http://skyvector.com/

Here is the list of sectionals:

http://www.naco.faa.gov/index.asp?xml=naco/catalog/charts/vfr/sectional

If you can't get a sectional, try a topographic "QUAD" for your area, you may need to look at quite a few quads.

I'm getting a sickening feeling that because of budget cuts, the government's own online free maps are going away, but there are enough free sources out there if you dig deep enough with Google.


Purple solid circles with lines in them are airports. The lines are the main runways. Circles with "H" in them are heliports. Purple solid circles with bigger yellow circles around them are controlled airspace airports, ie the larger airports.


Wiki has a picture for once.

File:FAA laser-free-zone.jpg - Wikipedia, the free encyclopedia

caveats:
This is not a 100% cure, as the flight routes into the airport may take a aircraft over your location, but its a start. Nor does it deal with low flying aircraft such as Lifeflight/police/newsgathering helos. Its also intended for lower power, high divergence devices, If you have a greater then 100 mW device, perhaps more planning is in order before going skyward.

How's that for a simple answer?

This doesn't cover local laws, nor is it a 100% fix, but it is a start.

Steve

 

[flogged]

Steve -

Excellent post. Normally I'm a 'live and let live' kind of person, and don't like any sort of regulation(s)..

However, 1 WATT of coherent focused light is very powerful, well beyond what I'd consider a sane level for any sort of 'pointer' device. The thought of this much power in the hands of an irresponsible person/whippersnapper makes me cringe.

As you mentioned, there's ample evidence that the higher visible frequencies (blue/violet) are intrinsically more damaging to cells of the retina than green and red light.

For example, see:
Information for Therapists on Light Therapy and Retinal Damage

So.. don't be stupid with these lasers, and protect your eyes!!

 

[flogged]

440nm light and eye damage

See these two links:

Information for Therapists on Light Therapy and Retinal Damage
Blue Light Therapy and Age-Related Macular Degeneration - AMD

from the second link:

Age-related Macular Degeneration (AMD) is a condition of advanced degeneration of the macular portion of the retina that leads to progressive blindness in over 35% of persons over the age of 75.1 AMD has been linked to the stress engendered by radical oxygen species in macular photoreceptor cells and proximate retinal pigment epithelium cells (RPE).2 Both of these types of cells are non-replicating (post-mitotic) and must respond to a lifetime of oxidative insult, which includes light-induced oxidative stress.3 While there are numerous mechanisms in the retina for preventing and forestalling oxidative insult, by middle-age many of these anti-oxidative mechanisms have begun to break down, which increases the susceptibility of the retina to accumulated damage with increasing age.4

Visible light absorbed by photoreceptors is a significant factor in the production of reactive oxygen species that induce the molecular damage in retinal tissue which appears to contribute to the formation of AMD.5 To an overwhelming degree, blue wavelengths of light produce the most oxidative stress within the retina and are primarily responsible for exacerbating the extent of oxidative damage that has begun to occur.6 Since blue light wavelengths impart the greatest risk of photochemical damage, the risk of retinal damage from light is termed "the blue light hazard", with the greatest hazard peaking at wavelength of 440 nm.7

Note the peak wavelength for retinal damage is around 440nm! Apparently below about ~470nm light is much more 'toxic' to retinal cells, especially for chronic long term exposure. This is really something to be aware of.

Protect your eyes!

I'd also suggest people take a look at this thread regarding some of the unique dangers of powerful blue lasers:
http://laserpointerforums.com/f65/plea-eye-safety-51464.html

This also applies to 405nm 'BluRay' lasers. It appears green and red lasers are more eye safe than blue ones.

 

[Razako]

Re: 440nm light and eye damage

You do know that the computer screen you're looking at right now is putting out light in the 445nm wavelength? I guess we'll all go blind from looking at our computer screens.

 

[flogged]

Re: 440nm light and eye damage

Not nearly as concentrated as 500-1000 mW of laser light.

I'd hazard you're gonna get a lot more retinal bleaching looking at the spot of a powerful laser compared to your computer monitor.

 

[Razako]

Re: 440nm light and eye damage

Not nearly as concentrated as 500-1000 mW of laser light.

I'd hazard you're gonna get a lot more retinal bleaching looking at the spot of a powerful laser compared to your computer monitor.

Yeah, but think of the amount of time you spend looking at the screen vs the amount of time looking at the spot of a 445nm laser. You shouldn't be looking at the spot of a 500mw+ laser up-close anyway without goggles. That's just asking to go blind.

 

[flogged]

Re: 440nm light and eye damage

True. This is just an 'FYI' on my part - I really don't know whether the links I posted are relevant to 440 nm lasers.

Understand the type of damage being discussed is more long term and cumulative, rather like how smoking increases your risk on cancer later in life.

 

[oic0]

Couple questions.
I'm running the Easy Haz calculator on 1.6watts 445 and it says 3.6 OD is enough to withstand 5+ seconds? I could have SWORN it told me 4+ last time I was there...

Anyhow, what do you guys think of the "OD 5+" Laser safety glasses from O-Like. I was thinking about getting a couple pair just to have but I'm not going to bother if they are crap.

 

[boscoj]

Woot . . . NoIr ARG and AL2 style 35 shipped !!! Thanks to David for the great support and time on the phone.

I asked him specifically about 445nm applications . . . here was his reply . . .

"AL2 would be to reduce the beam energy but to still allow some spot to be visible, where the ARG is for full attenuation."

Ready to pop some popcorn . . . one kernel at a time

NoIR LaserShields: Laser safety goggles for Argon and KTP lasers and applications.

 

[kingdave2357]

So how much blue exposure does it take to weaken the visibility of green light anyway, and does it last for a while or does it go away in a few minutes/hours. Im not talking about accidents or hits, just exposure to excess 445nm in class IV powers with normal use. Its almost like green isnt as bright as I remembered it, but is it because I am used to it now, or because of the 445nm?

 

[oic0]

So how much blue exposure does it take to weaken the visibility of green light anyway, and does it last for a while or does it go away in a few minutes/hours. Im not talking about accidents or hits, just exposure to excess 445nm in class IV powers with normal use. Its almost like green isnt as bright as I remembered it, but is it because I am used to it now, or because of the 445nm?

Green is a VERY important color for human vision. We are tuned to see more shades of it and see it the best (for obvious reasons). It would be a horrible color perception to damage for obvious reasons. You're probably just being paranoid though :tinfoil:

Maybe try color blind test by jean jouannic opticien ?