Performance indicators for astronomical telescopes

To evaluate the quality of a telescope, we first look at its optical performance, and then see whether its pointing accuracy and tracking accuracy are excellent. Xiaoci of Xiaocheng photoelectric group will give you an introduction to the basic knowledge of astronomical telescopes.

The optical properties are mainly included in the following indexes:

1. caliber: the effective aperture of the objective lens determines theoretically the performance of the telescope. The larger the aperture, the stronger the concentrating power and the higher the resolution, the larger the magnification can be.

2. gather light power: the ability to concentrate, the ratio of light to the amount of light received by the telescope. When the pupil is completely open, the diameter of the pupil is about 7mm. The 70mm aperture telescope has 70/7=10 times the light force.

3. resolution: the ability of the telescope to distinguish the details of the image. The resolution is mainly related to the caliber.

4. magnification: the ratio between the focal distance of the objective lens and the focal distance of the eyepiece, such as the pioneer 60/700 astronomical telescope, using the H10mm eyepiece, the magnification = the focal distance 700mm/ of the objective lens is 10mm=70 times the focal length of the lens, and the larger the magnification, the larger the image is.

5. field of view: the angle of the sky region of the telescope in the eyes of the observer, also known as the field of view. The larger the magnification, the smaller the field of 

view.

6. limit magnitude: the darkest magnitude observed by a telescope is mainly related to aperture and focal ratio. People with normal vision can see 6 stars at darkest in dark and air transparent occasions, while the 70mm aperture telescope has 100 times as much light as the naked eye, and can see 11 stars of five stars like 6 other stars.

Therefore, the important parameter to measure telescope is caliber.