As we discussed in the February 22 blog, solar eclipses may be indirectly viewed in a variety of ways. One of the simplest and least expensive (often coming at no cost) is to create a projected image of the Sun through a pinhole viewer. This may be accomplished by simply poking a small hole in a piece of cardboard, and then holding the cardboard such that the sunlight passes through the hole and falls onto a viewing surface (a white piece of paper, sidewalk, garage door, etc.) To focus the image, the observer simply moves the cardboard farther or nearer from the viewing surface.
Observers can get pretty creative with such pinhole viewers, devising a pattern of holes that spells out a word or forms a familiar shape like a heart.
“One of the simplest and least expensive ways to view an eclipse is to create a projected image of the Sun through a pinhole viewer.”
Another version of a pinhole viewer, one that needs no preparation, may be found in most kitchens. This is a colander, whose numerous holes are usually a perfect size to project the sun’s image.
While pinhole viewers are not useful during totality (you want to be looking at the eclipsed sun at this time anyway) they are perfect for easily seeing the partial phases of a solar eclipse.
By Kevin Schindler, Lowell Observatory Historian