On the evening of August 11, there will be a partial eclipse in China, and "dog bites the sun" will appear in the Middle East of China. So astronomers can't miss this rare astronomical phenomenon, so how to observe partial solar eclipse? What are the precautions for observing partial solar eclipse!
Introduction to partial eclipse on August 11, 2018
Time of appearance: evening of August 11
Occurrence time: up to 1 hour (varies by Region)
Viewing place: in the northern part of China, it can be seen that "dog bites the sun", in the central and eastern parts, it can be seen that "sunset with food", but not in the southeast of the coast.
There are three time nodes in the process of solar eclipse:
The first loss (beginning of eclipse), that is, when the moon approaches the sun, the first time the apparent circle of the sun and the moon is tangent, marks the beginning of eclipse in this place.
What to eat, that is, the moment when the center of the moon and the sun are closest, at this time, the part that sees the sun covered is the largest.
When the Moon leaves the sun, the second circumscribed moment of the apparent circle of the sun and the moon marks the end of the eclipse.
The degree and time of solar eclipse vary in different regions. Generally speaking, the earlier the northern eclipse occurs, the more perfect the process of solar eclipse is.
There are basically three ways to observe partial solar eclipse:
1. The easiest way is to find a piece of glass, put some thick ink on it or smoke it black, and watch the solar eclipse through the glass.
2. The effect can also be seen from the waste black-and-white negative film which has been exposed and contains metallic silver photosensitizer, but the time should not be too long.
3. There is no condition. It's also interesting to watch the images of partial solar eclipse on the ground directly under the shade of trees.
When observing partial solar eclipse, the public must not directly observe with the naked eye to prevent the sun from burning eyes. It is understood that if we miss this partial solar eclipse, if the Chinese public wants to enjoy it again, it will wait until January 6, 2019. This time, the visible range is relatively wide and the observation conditions are very good.
Watch notes:
The most important thing to pay attention to when observing a solar eclipse is the protection of the eyes. It is absolutely not allowed to watch it directly with the naked eye or through a telescope. The best tool for observing a solar eclipse is a professional eclipse mirror.
1. Do not use the naked eye to observe the solar eclipse directly. Please wear a special solar observation filter.
2. Don't watch the eclipse by looking at the reflection in the pond. In the water, the sunlight is only a little dark, but it can still cause great damage to your eyes.
3. Do not use a disc or a color negative as a filter. The optical disc and color negative film have very low extinction rate to the infrared part, which will cause permanent damage to the eyes.
4. In the partial eclipse stage, it is very dangerous to observe directly through binoculars, telescopes or even camera viewfinders. Special filters must be used for vision and photography!
5. Because there are no nerves in the retina, permanent visual damage caused by improper observation may not be found until hours later!
6. Even if 99% of the sun is covered by the moon, direct observation is very dangerous!
7. Sunglasses can't effectively block the band that will hurt your eyes!
8. If a partial solar eclipse is observed by projection, the surface of the projection screen must be rough.
9. If there is a star finder, don't forget to add a filter.
Main shooting points of partial eclipse on August 11, 2018:
It's no problem to take photos with your mobile phone; if you have zoom lens on your mobile phone, you'd better add protective filter.
Take photos with camera, especially SLR / DSLR, and remember to install filter on the lens.
1. The next day's partial eclipse has a major feature, that is, there are many places where you can take photos and eat sunset. In this way, the long focal lens (more than 200 mm) can be used in combination with the distant hilltop buildings to take photos of the ancient pagoda hanging in the sun. So the next day's partial eclipse recommends taking some photos combined with architecture.
2. The viewing effect of partial solar eclipse is not obvious, and it will not turn black like the total solar eclipse. Therefore, the viewing effect is not as good as the total solar eclipse. Do not expect the effect too much.
3. To shoot and watch the partial solar eclipse, there must be light reduction measures. Otherwise, shooting the sun directly with the lens will cause the sensor of the camera to burn out, and looking at the telescope with the eyes will also cause the eyes to burn out. It is not recommended to look at the sun with the naked eye for a long time. The commonly used dimming products are bud film. If the sunset light is not strong and there is some haze, the dimming mirror such as nd1000 can be used for protection.