Eclipse

[Uncwilly]

Originally Posted by Viliam Furik

I watched it too, with homemade eclipse glasses,

This is how people damage their vision.

[kriesel]

Originally Posted by Uncwilly

This is how people damage their vision.

Open air carbon arcs are pretty effective at close range too. (center electrodes from 2 dead zinc dry cells, on a 110v AC power cord; do not try this at home or elsewhere, alone, or without proper ventilation and protective gear. Or at all.)

[chalsall]

Originally Posted by Uncwilly

This is how people damage their vision.

LOL... I was wondering who was going to bat that ball first!

Hand-held pin-hole cameras are taught in elementary school.

And yet a certain POTUS looked at an eclipse without any eye protection recently (fortunately it was cloudy at the time; the US.SS security detail didn't fully understand the risk profile)...

[Viliam Furik]

Originally Posted by Uncwilly

This is how people damage their vision.

In my defense, they are very efficient. The sunlight going through was dimmer than my monitor's light, and I have measured the UV-B light coming through to be about 0% (our school physics teacher has a device for measuring UV-B radiation.). Measurement was done using real sunlight on a two-layer version in March, I think, so three layers should be plenty for June. They seem to only let through a bit of red-to-yellow mix because the sun looked orange through them.

[Uncwilly]

Originally Posted by Viliam Furik

I have measured the UV-B light coming through to be about 0% (our school physics teacher has a device for measuring UV-B radiation.)

0% of what? Don't you know that 0% (0.4% rounded) of the radiation inside the containment at Chernobyl is still bad for you? For reference the Sun's apparent magnitude is −26.7, that of the full Moon is about −11, and that of the bright star Sirius, −1.5. And that is a log scale. -23 will still hurt you.
And the UV-A, C, and IR values? The IR is just one part that will get you.

[masser]

Nice shots from Pittsburgh on twitter.

[Viliam Furik]

Originally Posted by Uncwilly

0% of what?

And the UV-A, C, and IR values? The IR is just one part that will get you.

About 0% of sunlight's UV-B, as I mentioned. For other UVs, I don't think the amount is much different. About IR, I don't think it can stop it, but neither can many things. For exposure as short as taking a look at an eclipse, I think even if I looked directly I would be ok after few minutes of seeing one big blur.

[fivemack]

1/4000 f/36 through cloud, after a short drive to get a bit south of Cambridge where the cloud cover was less complete:

https://www.chiark.greenend.org.uk/~twomack/eclipse.jpg

[Nick]

Originally Posted by fivemack

1/4000 f/36 through cloud, after a short drive to get a bit south of Cambridge where the cloud cover was less complete:

A great shot!

[MattcAnderson]

Courtesy of Astronomy Picture of the Day

https://apod.nasa.gov/apod/archivepix.html

Enjoy