I want to make a structural diagram of the telescope myself.

A telescope consists of an objective lens and an eyepiece. The convex lens or concave mirror near the scene is called the objective lens, and the one near the eyes is called the eyepiece. The light source of the distant scene is considered as parallel light. According to the optical principle, the parallel light will focus on one point after passing through a lens or spherical concave mirror, and this point is the focus. The distance between the focal point and the objective lens is the focal length.

Then a convex lens or an eyepiece with a shorter focal length than the objective lens can be used to enlarge the image. At this time, the observer feels that the distant scenery is magnified and can see clearly.

The structural diagram is as follows:

Extended data

Main parameters of telescope

1, caliber

The larger the aperture of the telescope, the greater the light collection capacity (the light collection capacity affects the brightness of the telescope field of view, etc.). The aperture of a telescope refers to the diameter of the objective lens, that is, the lens diameter of the telescope.

General telescope models will clearly indicate the aperture and focal length of the telescope. For example, Xinda 102/ 1000 refractive telescope, where the first set of numbers 102 represents the aperture (mm) of the telescope and the latter set of numbers is the focal length 1000mm (mm).

2. Extreme magnitude

Extreme magnitude (extreme magnitude affects the magnitude of the darkest object that a telescope can see). The larger the aperture of the telescope, the greater the limit magnitude that can be seen.

3. Limit rate

Limit magnification (limit magnification affects the maximum effective magnification that a telescope can get). Generally speaking, we think that the limiting magnification is twice the aperture of a telescope. For example, the limit magnification of the telescope with model 102/ 1000 is 200 times, but this is only theoretical. There are differences in the optical quality of telescopes of the same model and different brands, and an optically excellent telescope can exceed the limit magnification by about 50 times.

It should be noted that the magnification of the telescope is not as large as possible! Once the magnification exceeds the limit magnification (effective magnification) of the telescope, the image quality will be blurred and the details will be missing because of ineffective magnification.

Step 4 solve

Resolution (resolution affects the resolution of the telescope to the dark details of celestial bodies). The larger the aperture of the telescope, the stronger the resolution!

5, color difference

The longer the focal length of the common achromatic refraction telescope, the stronger the ability to control chromatic aberration. However, the larger the aperture, the longer the focal length, the larger the volume length of the telescope and the lower the portability.

6. Diversity

Telescope magnification calculation method: the focal length of the objective lens ÷ the focal length of the eyepiece, for example: 102/ 1000 model telescope, the focal length of the main mirror is 1000mm (mm), and the magnification is 1000 when using the eyepiece with1000 mm focal length.

7. Magnifier

Zoom lens (Barlow or Barlow lens): The focal length of the objective lens can be extended by two times (2X) or three times (3X) or more. The combined magnification of the telescope after using the zoom lens is the focal length of the objective lens ÷ the focal length of the eyepiece x the multiple of the zoom lens.

8. Pupil diameter

The exit pupil is the exit pupil. When you hold binoculars in your hand and look at the eyepiece of binoculars at about 30 cm, you can see two bright spots shaped like pupils, whose diameter is the exit pupil diameter. Like the objective lens diameter, the exit pupil diameter is in millimeters, and the exit pupil diameter is equal to the objective lens diameter divided by the magnification.

The exit pupil of the telescope first tells us the quality of the telescope: if the quality is excellent, the exit pupil is a clear and perfect circular spot, located in the center and surrounded by black.

For the prism model, the prism shadow in the light spot indicates that the prism is secondary glass (BK7), and the light leakage around it indicates that the mirror body has poor antireflection. The deviation of the exit pupil to one side or blue karyotype indicates that the internal optical axis is bent. The bigger the exit pupil, the sharper the image (low magnification), and the eyeball can easily see the image. It is suitable for use at sea and in a constantly vibrating environment.

9. Vision

The so-called field of vision is the range in which we observe the scenery. This value refers to the range seen at 1000 meters. The larger the field of vision, the larger the observation range.

References:

Baidu encyclopedia-telescope parameters