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Old August 21st 17, 09:37 PM posted to
Max Demian
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Posts: 3,970
Default Watching an eclipse

On 21/08/2017 21:15, Peter Duncanson wrote:
On Mon, 21 Aug 2017 21:03:08 +0100, Scott

On Mon, 21 Aug 2017 20:16:09 +0100, Andy Burns

Scott wrote:

people were watching using special sunglasses. I though no sunglasses
were safe for looking directly at the sun?

special eclipse viewing filters aren't sunglasses.

Okay, but are they safe? I was taught as a child that NO device was
safe to look directly at the sun and the ONLY way to watch an eclipse
safely was via a pinhole projecting on to a sheet of paper.

That's what Patrick Moore used to say, presumably in the days before
proper eclipse viewers were available. (They were made available in this
country for the 1999 eclipse. No-one bothered to sell any before.)

Yes, they are safe.

The only safe way to look directly at the uneclipsed or partially
eclipsed sun is through special-purpose solar filters, such as
“eclipse glasses”

We used to use a dark part of black and white negative film. When a
partial eclipse occurred during a chemistry lesson, our teacher got us
to smoke microscope slides with Bunsen burners before letting us go
outside to watch it.

It's OK unless you do something stupid.

Max Demian