Camera Obscura, dark room or a box with a hole on one side. On the other side, image rotated upside down could be seen, if a hole was small enough. People have known this principle of working from year 300 b.c..

"The image of the sun at the time of the eclipse, unless it is total, demonstrates that when its light passes through a narrow, round hole and is cast on a plane opposite to the hole it takes on the form of a moon-sickle. The image of the sun shows this peculiarity only when the hole is very small. When the hole is enlarged, the picture changes... ."

Leonardo da Vinci was first who made recordings on Camera Obscura, while Daniel Barbaro recommened it as an assistance on drawing.

"Close all shutters and doors until no light enters the camera except through the lens, and opposite hold a piece of paper, which you move forward and backward until the scene appears in the sharpest detail. There on the paper you will see the whole view as it really is, with its distances, its colours and shadows and motion, the clouds, the water twinkling, the birds flying. By holding the paper steady you can trace the whole perspective with a pen, shade it and delicately colour it from nature."

Giovanni Battista della Porta (1538-1615) was first man that made big "camera", seated few persons and asked others to observe image on the wall. Upside down images were too much for poor observers to handle. Story ended as Battista was brought to court on a charge of sorcery.

Taking pictures means manipulating with light, composition and colours, waiting for a right moment, "sorcering", to put it mildly.

I used that method to see an eclipse about 7-8 yrs ago. It was shown on TV. So I made a box with a hole and saw the eclipse through the hole.

Yeah, using one of those to look at an eclipse is a good idea, since looking directly at the sun is a very bad idea.

The phrase "camera obscura" is a Latin term, meaning "dark chamber," and is the basis of the modern camera. Some kids would make a pin-hole camera in school, which is kind of like the one used for viewing an eclipse.