On Thu, 17 Aug 2017 12:47:53 -0700 (PDT), wrote:

On Thursday, May 17, 2012 at 1:53:14 PM UTC-4, 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

you can not stack the lens, can still have severe damage, this is coming directly from NASA.

Direct from NASA, who also gave us Global Warming.

So, you're steering people into buying the cardboard and mylar eclipse
viewing glasses from the Dollar Tree, are ya?

I'll take my chances with indirect viewing, thanks. Having used
pinholes in cards before, I know it works and is detailed. Will try
the binoculars this time, directed onto a card underneath, hopefully
with a larger picture than the pinhole.

-
I am a Transfinancial--A rich person born in a poor person's body.
Please stop the hate by sending me money to resolve my money
identity disorder. --anon