Question Eclipse Glasses PSA

If anybody here is planning on watching the eclipse using paper eclipse glasses, be aware that the market is being flooded with Chinese counterfeits.

eclipse.aas.org/eye-safety/iso-certification
qz.com/1040159/solar-eclipse-glasses-for...ety-recommendations/

Amazon is sending out emails to purchasers of glasses they can't verify (I know, because I got one), but if you got your glasses from another source, please double check them!

The safe way to watch the partial phase of an eclipse is a pinhole camera.

Use two pieces of white card (or paper, but card is easier to handle).
Make a SMALL hole in one. This will project an image of the sun onto the second piece held below it.
Completely safe, since you never look at the sun. Only look at it directly during the total eclipse itself.

Here's a helpful page from NASA about safe eclipse viewing:

eclipse2017.nasa.gov/safety

Meanwhile, the next total eclipse visible from the UK is in 2090 - so basically the only way anyone living in the UK can view an eclipse is to travel (the last one in 1999 covered bits of Cornwall and Devon, everywhere else only experienced a partial eclipse).

NASA's advice is, I'm afraid, incorrect (sadly, as an amateur astronomer of nearly 60 years, official bodies often dont have the best info)

The problem with eclipse glasses is that (1) they have to be made correctly, and (2) the material used is often inadequate.
There are only 2 types of material I consider safe. One is fully exposed X-ray film (which is opaque in the IR and UV). Most 'black' films only cover the visual spectrum. Very few commercial glasses are safe.
Also safe are the silver mlylar glasses (the silver, actually usually aluminium, reflects and absorbs the IR and UV again.)

The real issue with commercial glasses is that you have no way of telling if they are cheap and dangerous knockoffs. A mylar set is safer, as they cant screw you with a cheap and inadequate film, but I would still be leery at buying off amazon.
A mylar film is what I use to take images of the sun with.

The pinhole camera is perfectly safe.A bad set of glasses can damage you eyesight permanently during the eclipse.

Astrodragon wrote: NASA's advice is, I'm afraid, incorrect (sadly, as an amateur astronomer of nearly 60 years, official bodies often dont have the best info)

The problem with eclipse glasses is that (1) they have to be made correctly, and (2) the material used is often inadequate.
There are only 2 types of material I consider safe. One is fully exposed X-ray film (which is opaque in the IR and UV). Most 'black' films only cover the visual spectrum. Very few commercial glasses are safe.
Also safe are the silver mlylar glasses (the silver, actually usually aluminium, reflects and absorbs the IR and UV again.)

The real issue with commercial glasses is that you have no way of telling if they are cheap and dangerous knockoffs. A mylar set is safer, as they cant screw you with a cheap and inadequate film, but I would still be leery at buying off amazon.
A mylar film is what I use to take images of the sun with.

The pinhole camera is perfectly safe.A bad set of glasses can damage you eyesight permanently during the eclipse.

Last eclipse I was at work and I used my welding helmet and a few number twelve filter plates I shared with other workers who wanted to take a peek.

I may have made an unwarranted assumption that filters designed to protect you against the light of an arc welder would be good enough. It's what I'd use this time around if someone does not tell me different.

peter wrote:

Astrodragon wrote: NASA's advice is, I'm afraid, incorrect (sadly, as an amateur astronomer of nearly 60 years, official bodies often dont have the best info)

The problem with eclipse glasses is that (1) they have to be made correctly, and (2) the material used is often inadequate.
There are only 2 types of material I consider safe. One is fully exposed X-ray film (which is opaque in the IR and UV). Most 'black' films only cover the visual spectrum. Very few commercial glasses are safe.
Also safe are the silver mlylar glasses (the silver, actually usually aluminium, reflects and absorbs the IR and UV again.)

The real issue with commercial glasses is that you have no way of telling if they are cheap and dangerous knockoffs. A mylar set is safer, as they cant screw you with a cheap and inadequate film, but I would still be leery at buying off amazon.
A mylar film is what I use to take images of the sun with.

The pinhole camera is perfectly safe.A bad set of glasses can damage you eyesight permanently during the eclipse.

Last eclipse I was at work and I used my welding helmet and a few number twelve filter plates I shared with other workers who wanted to take a peek.

I may have made an unwarranted assumption that filters designed to protect you against the light of an arc welder would be good enough. It's what I'd use this time around if someone does not tell me different.

IIRC, Arcwelding filters are ok - they are normaly designed to filter out the dangerous stuff, and should be fine if just used visually.
I didn't mention them because they are pretty rare.

By the way, NEVER use a piece of colour film as a filter, the dyes used in it dont stop the nasty stuff. Only old fashioned silver emulsions with EXTREMELY high contrast can do this (and you dont find these in your typical camera store). Hence the recommendation of X-ray film, its extrmeley high contrast with a dense silver emulsion.

Astrodragon wrote: By the way, NEVER use a piece of colour film as a filter, the dyes used in it dont stop the nasty stuff. Only old fashioned silver emulsions with EXTREMELY high contrast can do this (and you dont find these in your typical camera store). Hence the recommendation of X-ray film, its extrmeley high contrast with a dense silver emulsion.

Heh.. yeah, years ago we were using a high-end film for printing and would expose a full sheet and use that to look at the sun

Astrodragon wrote: NASA's advice is, I'm afraid, incorrect (sadly, as an amateur astronomer of nearly 60 years, official bodies often dont have the best info)

The problem with eclipse glasses is that (1) they have to be made correctly, and (2) the material used is often inadequate.
There are only 2 types of material I consider safe. One is fully exposed X-ray film (which is opaque in the IR and UV). Most 'black' films only cover the visual spectrum. Very few commercial glasses are safe.
Also safe are the silver mlylar glasses (the silver, actually usually aluminium, reflects and absorbs the IR and UV again.)

The real issue with commercial glasses is that you have no way of telling if they are cheap and dangerous knockoffs. A mylar set is safer, as they cant screw you with a cheap and inadequate film, but I would still be leery at buying off amazon.
A mylar film is what I use to take images of the sun with.

The pinhole camera is perfectly safe.A bad set of glasses can damage you eyesight permanently during the eclipse.

Are you saying that glasses that meet ISO 12312-2 aren't sufficiently protective?

I mean, yes, you still have a problem with verifying that the glasses actually meet the standards that the manufacturers claim. But shouldn't an independently certified lens from a reputable manufacturer be perfectly fine?

more info here

gizmodo.com/amazon-is-cracking-down-on-f...s-that-co-1797796665

I bought a solar filter for my camera, but you still have to use the screen and not the viewfinder.

Arcanist Lupus wrote:

Astrodragon wrote: NASA's advice is, I'm afraid, incorrect (sadly, as an amateur astronomer of nearly 60 years, official bodies often dont have the best info)

The problem with eclipse glasses is that (1) they have to be made correctly, and (2) the material used is often inadequate.
There are only 2 types of material I consider safe. One is fully exposed X-ray film (which is opaque in the IR and UV). Most 'black' films only cover the visual spectrum. Very few commercial glasses are safe.
Also safe are the silver mlylar glasses (the silver, actually usually aluminium, reflects and absorbs the IR and UV again.)

The real issue with commercial glasses is that you have no way of telling if they are cheap and dangerous knockoffs. A mylar set is safer, as they cant screw you with a cheap and inadequate film, but I would still be leery at buying off amazon.
A mylar film is what I use to take images of the sun with.

The pinhole camera is perfectly safe.A bad set of glasses can damage you eyesight permanently during the eclipse.

Are you saying that glasses that meet ISO 12312-2 aren't sufficiently protective?

I mean, yes, you still have a problem with verifying that the glasses actually meet the standards that the manufacturers claim. But shouldn't an independently certified lens from a reputable manufacturer be perfectly fine?

The issue with all these iso standards is that they dont actually prove the kit is fit for purpose. It just proves they went through an approved quality control process.
Now a reputable firm will make sure this process involves suitable testing - but there is not actual requirement to do so!

My advice would be, if you really want to use glasses, get mylar or buy from an astronomy shop rather than a retailer.

When we had the last big solar eclipse in the UK (1999) there was a set of government approved and tested glasses, which helped. I dont know what the situation is in the USA.

I'm afraid I still don't understand. Why wouldn't glasses that filter the required amount of light be fit for the purpose of viewing the sun?

Arcanist Lupus wrote: I'm afraid I still don't understand. Why wouldn't glasses that filter the required amount of light be fit for the purpose of viewing the sun?

They have to not only filter the visual part of the light, but also the UV and near IR. Your eye will focus these, just not well.
The issue with the dodgy glasses is they just use a cheap film that tends not to filter these out, and may also allow too much visual light through as well.
You cant tell if your retina is being damaged until its too late.

I haven't read the ISO myself because of the paywall, but doesn't it cover the IR and UV requirements as well?

I totally get what you're saying about dodgy manufacturers and being unable to verify the safety of the glasses yourself.

Arcanist Lupus wrote: I haven't read the ISO myself because of the paywall, but doesn't it cover the IR and UV requirements as well?

I totally get what you're saying about dodgy manufacturers and being unable to verify the safety of the glasses yourself.

Paywalled for me too. Just that after many years of ISO and other standards, I have a lack of faith in them...

It's also worth noting that the only safe time is during the total occlusion, which is a couple of minutes at best.



The only time it is safe to look at it is the very dead center. The "Baily's beads" (to the left and right of the center) are just as unsafe as the full disc for your eyeballs!

I am still unsure as to my plans for the eclipse. I live 2.5 hours from the nearest point of the total eclipse, but that is in a lake. So I am unsure if I am going to make the trip or not. Friends of mine are going to that hotbed of culture that is Carbondale IL, but I don't want to deal with the crowds. My initial plan was find a nice empty back road that I could sit on.

Do you think Carbondale going to be bad?

We were looking at that as an alternate destination to Kentucky, which is looking to expect on the order of a million people for the very small town the eclipse is centered on.

Katssun wrote: Do you think Carbondale going to be bad?

We were looking at that as an alternate destination to Kentucky, which is looking to expect on the order of a million people for the very small town the eclipse is centered on.

It's going to be very crowded. It is the "largest" city nearest the greatest point of totality. So there are lots of large groups that are going to be there. NASA, several planetariums, Universities, etc. and all in a city of 25,000. I went to school there, there isn't much there.

As XKCD points out:

I figure if you've seen one total eclipse, you've seen them all. And I vividly remember the 1979 eclipse, when I was in grade school; I was lucky enough to be in the path of totality then. I'll settle for 95% or whatever we're getting here this time.

My end of Knoxville was only eight miles away from the path of totality, so I headed down to Farragut to check it out. Glad I did; hadn't realized how bright and pretty the corona would be. In hindsight, though, I should have taken better precautions against sun damage. My glasses worked fine, but it turns out my tree had an insufficiently high SPF, so now I'm sporting a new hue.

Well, I hope everyone enjoyed the eclipse that wanted. It was rather nice here, cloudy with a touch of rain, and no visible sun. Just the way I like it. (the sun and I have an understanding, it doesn't like me, I don't like it)

Kettlekorn wrote: My end of Knoxville was only eight miles away from the path of totality, so I headed down to Farragut to check it out. Glad I did; hadn't realized how bright and pretty the corona would be. In hindsight, though, I should have taken better precautions against sun damage. My glasses worked fine, but it turns out my tree had an insufficiently high SPF, so now I'm sporting a new hue.

You didn't pop?

I work at a hotel on I 57 a few hours (normal travel time) north of the path of totality. It is currently about 2 AM local time and I have no rooms left, and my phone is still ringing about every 4-5 minutes and a car pulls up about every 10 minutes. To top it all off there is heavy thunderstorm over the area right now.

In 7 years everyone plan better.

I got lucky. It was predicted to be mostly cloudy in St. Louis with a possibility of rain, but while there were a few clouds we got a fully uninterrupted view of totality. We watched from a wolf sanctuary (and afterwards we got to see the wolves!) with reservations required so it wasn't too crowded, and we stayed with relatives so we didn't have to worry about dealing with hotels. All and all, it was pretty sweet.

yes?

I didn't go outside since where I am it was only about 80% coverage and I didn't have glasses anyway, nor an interest in making a pinhole camera so I could see something indirectly... if I'm gonna see it I'll use youtube like most everyone else...

Kristin Darken wrote: I slept through it.

Honestly.

Does that make me a horrible person?

I don't know. Were your eyes open when it passed by? Else no. It was eaten by a dragon, but was beaten back by a fluffalo.

I didn't bother looking, since I was some 10 thousand kilometers south of the path of totality.

Sir Lee wrote: I didn't bother looking, since I was some 10 thousand kilometers south of the path of totality.

Awwwww You missed it. Shame, I was blinded by the light.

I was right in the middle of the path. It was cool, but I must have been an astronomer or something in a past life, because I just felt jaded about the whole thing. Maybe it was the enthusiasm of my friends and family that sapped me.

Kristin Darken wrote: I slept through it.

Honestly.

Does that make me a horrible person?

Not at all. If you want to sleep through the most interesting astronomical phenomena in our general vicinity, that is your prerogative.

And honestly, if you're only in view of the partial there isn't much value to watching with your own eyes that you can't get from pictures.

Kristin Darken wrote: I slept through it.

Honestly.

Does that make me a horrible person?

I did too, but I get another chance in 7 years.

Valentine wrote:

Kettlekorn wrote: My end of Knoxville was only eight miles away from the path of totality, so I headed down to Farragut to check it out. Glad I did; hadn't realized how bright and pretty the corona would be. In hindsight, though, I should have taken better precautions against sun damage. My glasses worked fine, but it turns out my tree had an insufficiently high SPF, so now I'm sporting a new hue.

You didn't pop?

Corn only pops once unless you get creative; otherwise it just burns. But in this case, the problem was radiation damage, not heat; it was only in the high 80s and there was a little breeze, so I was pretty comfortable.

Valentine wrote: I work at a hotel on I 57 a few hours (normal travel time) north of the path of totality. It is currently about 2 AM local time and I have no rooms left, and my phone is still ringing about every 4-5 minutes and a car pulls up about every 10 minutes. To top it all off there is heavy thunderstorm over the area right now.

In 7 years everyone plan better.

I was stuck in that legendary traffic jam! 6 hours of bumper to bumper to go the 60 miles from Carbondale to I-70. Then the rest of it wasn't so bad, and we got back to our hotel far away from that nightmare.

My understanding is that the traffic jam went all the way to the Chicago suburbs.

We did get to see the totality. It was very pretty. The whole area cheered when the clouds parted just in time.

About 80% in my area. The only spectacular bit was apparent in retrospect: when I went out to see how the eclipse was progressing, the mid-afternoon heat wasn't as oppressive as usual - breezier than normal, the heat index was down a solid 5C, the usual sunburning feeling wasn't as bad. (Don't let anyone convince you that August in South Florida is wonderful.) Today's much better - the sun hasn't been out at all!