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Old August 22nd 17, 07:44 AM posted to
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Default Watching an eclipse

On Mon, 21 Aug 2017 22:24:13 +0100, Andy Burns

Huge wrote:

I've watched two through (arc) welding filters.

Quite a chunk of the ISO/BS standard is lifted from section 4.1 of this
NASA document

exposed B&W film provided you know it's a silver-based film

I was going to ask if such safe methods existed in the 1960s then I
realised there was probably more welding (in the UK) and more
monochorme film in these days :-)