mike wrote:
I want to look at the eclipse this weekend.
Everybody says a #14 welding shade is good.
I don't have one.

So, how do the numbers stack up when you use 2?
I'm guessing it's not linear, so 7+7 doesn't = 14???

What's the math for stacking welding shades?

Thanks, mike


A much better idea is to punch a pinhole in the center of one end of a
shoebox , and tape a piece of white paper inside the other end . Point the
pinhole end at the sun , there will be an inverted IIRC image of the sun
on the paper if you've lined it up properly . Similar in principle to a
pinhole camers , you might google "pinhole eclipse viewer" or similar for
more info .
Welding lenses are not really suitable for viewing the sun , though many
people do it ...;
--
Snag
Learning keeps
you young !