The photosphere (diamond ring, etc) is not dangerous if you only see it for 1 or 2 seconds. It is prolonged, central-vision, fixed staring that takes more than a few seconds that is dangerous.
So when the diamond ring comes out, take one look at it. But that's it, one look. Then turn away and put your goggles on. You'll be fine as long as you don't linger beyond a couple seconds.
The problems begin when people keep staring at it fixedly beyond a handful of seconds.
> The difference between a 99.9% partial eclipse and a 100% total eclipse is not 0.1%. It is infinity.
Well put.
Indeed, at the end of totality in the 1979 eclipse, I kept looking at the diamond ring and Baily's beads for a second or two with my binoculars. It did not damage my vision at all.
In the weeks leading up to this year's eclipse, I almost felt like it was my civic duty to correct some of the misinformation that was going around in the media. I had a feeling that many thousands of people who went to considerable trouble and expense to go to the path of totality would miss it entirely, because they got scared into keeping their eclipse glasses on the whole time.
There was such a fear campaign going on, just like the one in 1979 when Oregon schools changed their hours to keep the children indoors during totality.
This TV report was a good example:
http://www.kptv.com/story/36143862/portland-man-shares-warni...
The gentleman in the report did unfortunately damage his vision by staring at the 1963 partial eclipse - for 20 seconds! Truly a sad thing, but in the video they kept talking about the dangers of staring at a partial eclipse, while showing photos of a total eclipse - as if there was no difference between the two!
I tried to set the record straight in the comments, but man, it was an uphill battle. Read the comments and weep...
At the deepest partial phase, you see Baily's Beads and the Diamond Ring. This is still the sun's photosphere peeking through the moon's valleys, bright enough that it washes out the corona, and bright enough that you had better use eye protection. Only when the moon completely blocks the photosphere do you see the solar corona.
This is totality. This is where you no longer need (and can't use) the protective glasses or filters or pinhole projectors. During totality, you can view the corona with your own eyes, with no protection, and even with binoculars.
The difference between a 99.9% partial eclipse and a 100% total eclipse is not 0.1%. It is infinity.