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Old August 21st 17, 10:24 PM posted to uk.tech.digital-tv
Andy Burns[_12_]
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Posts: 411
Default Watching an eclipse

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

https://eclipses.gsfc.nasa.gov/SEpubs/2010/TP214171a.pdf

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