100 power spotting scope
Heysoos Aitch Kreist, don't follow this advice. I know he's kidding, but...
You can project an image of the eclipse onto a screen using binocs or a scope, but looking at the eclipse directly
through a scope or binocs
without heavy filtering is dangerous. Sunglasses won't cut it, hence the remarks about heavy ND (Neutral Density, i.e. colorless, or gray) filters from a welding shop.
The screen itself may start to smoke before totality, too, depending on the optical device used to project the image.
You can also use a pinhole camera-like (look up
camera obscura) arrangement to view the proceedings, but resolution of the image may not be the greatest, depending on the size of the "pinhole."
Around the times and locales of the eclipse, local media will give plenty of warnings about all this, but some folks just won't get the word.
It takes quite a bit of coordination and rehearsal WRT viewing devices, when to insert and remove filters, etc, etc, to capture a full solar eclipse adequately.
The business about "stacking" ND filters is good, because the available light becomes less and less as the eclipse approaches totality, and you can rapidly remove filters (with rehearsal) as it approaches a full annular eclipse.
By way of definitions, "full annularity" is the center image, courtesy Sky and Telescope magazine:
http://www.skyandtelescope.com/wp-content/uploads/May20_Eclipse_series_556px.jpgTerry
