What are the safe ways to observe the total solar eclipse? (The more, the better)

First, using the pinhole imaging principle, poke a small hole in a piece of paper, let the sunlight project onto the wall or white screen through the small hole, and watch the process of the sun being "bitten".

Second, use a small telescope to project the image of the sun on the screen, so that you can observe it. At the same time, you can trace. But you can't look directly at the sun through a telescope without a filter!

Third, look through the filter. Observe through qualified eclipse observation glasses, eclipse observation cards and welding goggles, or add a filter to the objective end of the telescope.

Be sure to buy qualified sun observation glasses! For example, a solar observation mirror with a Budd film. Daily sunglasses or sunglasses are only used to observe the surrounding scenery in the sun, and must not be used to look directly at the sun! In addition, unqualified sun observation mirrors and filters, such as smoked glass, beer bottle bottom, color or black-and-white film (no matter how dense it is, whether it is exposed or not), floppy disk, neutral density filter or polarization filter for photography, and solar filter at eyepiece, cannot be used.