How to maintain astronomical telescope

How to maintain astronomical telescope

1. Anti-mildew It is very important to place and store the telescope in an appropriate way to prolong its service life. The telescope should be stored in a dry and ventilated place with little dust, mainly to prevent the surface of the lens from becoming moldy. Mold is the enemy of the telescope. Usually, we are very careful about the use and maintenance of astronomical telescopes, so the mildew of the lens exceeds the mechanical damage and becomes the main reason for the decline or even scrapping of the telescope. The ambient temperature is between12 and 38 degrees Celsius, and the relative humidity is above 60%, which is the best condition for mold growth. Keeping the ambient light dry and ventilated is the best way to prevent mold from invading the telescope system. In the rainy season in the south, the optical components of the telescope should be placed in the drying box as much as possible. At present, there are two kinds of drying boxes commonly used, which can be bought in larger photographic equipment stores. One is a sealed box, usually plastic. If you can't buy a special sealed box, you can use a plastic fresh-keeping box or a sealed bag with good sealing performance instead. Just put a desiccant in a sealed box. The commonly used desiccant is color-changing silica gel, which is available in chemical stores. Dry silica gel is a small blue ball that turns pink or white when wet. At this time, it can be fried in a clean pot, dried in a microwave oven or dried in the sun. After removing water, the silica gel will return to its original blue color. The other is an electronic moisture-proof cabinet, which adopts an electronic dehumidifier core and can automatically dehumidify according to the set relative humidity. There are many domestic and imported brands to choose from at present. The optimum relative humidity for storing optical instruments is 45% ~ 55%. If the telescope is found to be moldy, it should be cleaned as soon as possible. Usually, early mildew spots can be completely removed by cleaning.

2. Avoid sudden temperature changes. If possible, the commonly used telescope should be placed near the ambient temperature, so that the temperature of the telescope can be balanced with the ambient temperature as soon as possible, and the temperature change may also cause problems of the telescope itself. In the process of using the telescope, drastic temperature changes should be avoided. When an air-conditioned room is moved outdoors, dew may form on the surface of the lens and mirror body, which will not only damage the electrical parts of the telescope, but also cause mildew on the telescope if it is stored in a closed place before the dew dries out. The correct way is to put the telescope in the box first, and then move it to a place where the temperature is very different. The packaging box can slow down the temperature change of the telescope itself, and the telescope will not condense after a period of time.

Step 3 clean the mirror. If there is no suitable packing box, pay attention to dust prevention when the telescope is not in use. In addition to covering the lens cover, it is best to cover the mirror body with a plastic bag or a clean cloth. Large household garbage bags sold in supermarkets are very suitable for telescope dust prevention. No matter how carefully you use it, there will always be more and more dust falling on the mirror. The influence of a small amount of dust on the final imaging of the telescope is imperceptible to the naked eye and does not need to be cleaned frequently. However, if a thick layer of dust falls on the surface of the objective lens, it will reduce the brightness and contrast of imaging and need to be cleaned in time. The outer surface of the eyepiece is more easily contaminated than the objective lens, which has a greater impact on the observation effect, especially for the high-power eyepiece with short focal length. Because of the short distance from the pupil, the eyes should be close to the eyepiece when using, and the eyelashes are easy to leave oil stains on the lens, which needs to be cleaned frequently. If you don't have rich experience in adjusting the optical system of the telescope, cleaning the telescope lens should be limited to the outer surface of the objective lens and eyepiece, which is also the easiest place to get dirty. For the dust falling on the lens, you should first blow it off with balloons (available in photographic equipment stores) or medical ear washing balls (available in pharmacies). Be careful not to blow the mirror with your mouth, or the saliva falling on the mirror will make cleaning more difficult. Dust that can't be blown off can be gently brushed off with a fine camel brush, and finally it can be gently glued off with absorbent cotton balls (available in pharmacies) or cosmetic absorbent cotton sticks (available in supermarkets) dipped in distilled water or pure water. After confirming that there are no dust particles visible to the naked eye on the surface of the lens, you can use the soft pad of "mirror pen" (which looks like a thick pen, with a fine brush at one end and a soft pad with detergent at the other end, which can be bought in photographic equipment stores) to wipe the lens from the center. Pay attention to the constant rotation of the mirror pen and moderate force during wiping. The mirror pen is an effective tool for cleaning the lens. With its soft leather pad, the water and fingerprints on the lens can be easily wiped off without leaving any traces. For stubborn stains that can't be removed once with a mirror pen, you can take a breath in front of the mirror and wipe them clean before they are dry. The mirror pen also has a very good cleaning effect on newly emerging mildew spots. It should be noted that if there is water or heavy moisture on the mirror surface, it should be cleaned with a mirror pen when it is dry. There is a special cleaner in the cap of the mirror pen. After one use, insert the cushion into the bottle cap and rotate it again, and the detergent will be redistributed on the cushion. In addition to the mirror pen, there are some common tools for cleaning the lens, such as lens paper and suede. However, it is easy to leave slight scratches on the mirror surface during use, and the cleaning effect is difficult to compare with that of the mirror pen.