Looking directly at the Sun without protection is dangerous. The only safe way to look directly at the uneclipsed or partially eclipsed Sun is through special-purpose solar filters, such as “eclipse glasses” or handheld solar viewers. Homemade filters or ordinary sunglasses, even very dark ones, are not safe for looking at the Sun. Cameras, telescopes, binoculars, and other optical devices must also be equipped with filters in order to be used safely. Here's how you can view the solar eclipse safely:
Eclipse glasses are made with special-purpose solar filters according to international standards (ISO 12312-2). Free eclipse glasses are available at the Sciences Library and the Museum of Natural History.
The American Astronomical Society and NASA recommend the following sources for ISO-certified eclipse glasses:
According to experts, number 14 welder's glass is also safe for solar viewing.
Telescopes with solar filters are the best way to view a solar eclipse. On the day of the eclipse, the Physics & Astronomy Department will set up telescopes with solar filters on the Pentacrest and in the courtyard outside the Sciences Library. Never look at the Sun through an unfiltered telescope.
Pinhole projectors and other projection techniques are safe, indirect methods for viewing a solar eclipse. It's easy to make your own pinhole projector:
On the day of the eclipse, a projection telescope will be set up in the courtyard outside the Sciences Library.