How to make a sunfinder goggles? On July 22, we will see a total solar eclipse

Information from DIY Daquan:

Experts from the Purple Mountain Observatory teach the public to make their own observation glasses

First, the film that has been directly used is used as a lens;

The second is to smoke a thick layer of carbon on ordinary sunglasses, the darker the better;

The third is that the black film in the floppy disk can also be used as a lens;

The fourth is to coat the glass with a thick layer of black ink. Acts as a lens after drying.

Except for when the moon completely obscures the sun's rays, you can take off your glasses to enjoy it, and at other times, citizens need to wear these sunglasses to enjoy a total solar eclipse. The expert reminded.

The most professional opinion: use special eclipse glasses on the market**.

Feasibility evaluation: professional enough, naturally different, its effect is needless to say. But a total solar eclipse is not a sunrise, it can be seen every day, maybe you can buy and pay for glasses next time you use it, and it is possible to wait another 360 years.

A more professional view: look at it with welding goggles.

Feasibility evaluation: Welding goggles are designed to protect the eyes under strong light, and you can use it to look directly at the sun. Unless you have relatives and friends who are in the industry related to welding goggles, that stuff is really hard to find.

The best way to do it: look at it on waste film (or X-ray).

Feasibility evaluation: Rip out the newly bought film and let it completely**. Two or more pieces of waste film stacked on top of each other can be used to look at the sun.

Or go to the hospital to find a used X-ray can also achieve the same effect, but you must make sure that it is dark enough, otherwise the protection effect will not be too good.

The least environmentally friendly view: look at it with blackened glass.

Feasibility Evaluation: Use a fire to bake a piece of glass black, which can be used to look at the sun. But now it is not easy to find a piece of glass in the city, and in addition, the black substance that appears on the glass is carbon particles that are not fully burned, and now every family has the same gas and natural gas, and these gases are fully burned and do not produce this substance.

How to blacken the glass is a question worth considering.

The most technical view: the small hole imaging method.

Feasibility evaluation: This method requires high manual skills for the maker, the appearance of the small hole instrument can be made like an astronomical telescope, the main body is a straight tube with an inner diameter of not less than 2 cm and a length of one or two meters, one end of the tube is covered with a translucent flat plastic film or ground glass to make a projection screen, and the other end is sealed with opaque cardboard, and then in the middle of the cardboard, a small hole is pierced with a needle, and it is good. During a solar eclipse, the small aperture is set up with a bracket like a telescope, and the small hole is aimed at the sun, and a small and clear image of the sun can be obtained on the projection screen with a slight adjustment.

The image is stabilized for easy observation. It is the biggest advantage of the small hole instrument; But is your craft level passing?

Look with total solar eclipse glasses.

There are two main factors that cause damage to the eyes from a total solar eclipse: one is the strong light of the sun. Sunlight is a million times stronger than moonlight, so you can't use the naked eye or use a telescope without a light-reducing device**, otherwise it is easy to cause retinal damage and even permanent blindness.

There is data that staring at the sun for 10-30 seconds blinds. The second is the sun's ultraviolet radiation. Seepage ultraviolet rays are not felt by the human eye, and at the same time, it is also said that the cheating is not filtered by ordinary sunglasses, and the eyes are directly exposed to ultraviolet rays for a long time, which will cause serious damage to the retina.

The duration of this total solar eclipse is about 2 hours and 38 minutes from the beginning of the eclipse to the full circle. The total eclipse lasts for more than 5 minutes. Therefore, the safest way to visually observe a total solar eclipse is to wear 1 pair of total solar eclipse glasses.