Today, there will be a solar eclipse for the northern hemisphere.
Everyone on the west coast will enjoy a dazzling afternoon, and early "sunset".
Unfortunately, everyone on the east coast will not see it at all, and people a little inland of the east coast will get it at the same time as sunset.
[SIZE="3"]For those of you who lack welding masks, or highly tinted materials[/SIZE]
Making a pinhole lens is a cheap and easy way to still view an eclipse safely, though the effect is not quite as stunning.
Making a pinhole lens is as easy as getting a piece of paper and poking a hole into it, but to make one that will produce an image big enough to watch an eclipse with requires some before-hand set up.
To start off with, find out where you want to watch the eclipse. For that, you'll need to know the time of the eclipse, so that you can roughly estimate where the sun will be. This is because you will require a flat surface roughly perpendicular to the sun in order to use a pinhole lens this way.
Once you know where you'll be, and how much room you have to work with, you'll need to find a sufficiently large piece of regular or cardboard paper. Because of the way pinhole lenses work, the larger it is, the better it is, regardless of how small the pinhole is.
Once you're satisfied with your aperture material, poke a hole in it. For sophisticated pinhole lenses, the hole should be as small as possible, but you're going a different route, so as long as the hole is relatively small, it's fine. We're gonna gradually make it bigger and bigger, so go ahead and start fairly small.
Then you need to focus it. Take it somewhere else that has a flat surface perpendicular to the sun, and hold it up rather close. Move it away gradually, and the point of light will begin to grow. That small circle of light is actually an image of the sun. But we want it to be big enough to see important details, so we're not done yet.
Here is the important part: Continuing to move the lens away from the surface will cause the image to grow, but not lose intensity. Once the image begins to get darker, then you know you can make the hole bigger, only for that distance. If you make the hole too big, it won't be a lens at close distances, and unless you have a massive piece of paper, it won't even be a lens at very far distances. That's why you keep moving the paper away and making the hole bigger only a little at a time, until you know how big you can potentially get your image, as well as how far away you have to be.
To get an image of a few inches in diameter, you'll have to have a rather large piece of cardboard, and about one and a half meters worth of space between the lens and the viewing surface. To get an even larger image, you're looking at several meters of space or more, so find a spot where setting up the lens is even possible.