What does a telescope magnification 9 40 refer to

9x magnification, objective lens diameter 40 mm.

The telescope 10x50 means: the aperture is 50mm, and the magnification is 10x.

The first purpose of a telescope is to magnify the opening angles of distant objects, so that the human eye can see details with smaller angular distances. The second function of the telescope is to feed the beam of light collected by the objective lens that is much thicker than the diameter of the pupil (up to 8 mm) into the human eye, allowing the observer to see faint objects that were previously invisible.

Common parameters:

1. Magnification.

Generally, the ratio of the angle of view of the eyepiece to the angle of incidence of the objective lens is used as the magnification of the telescope, and the ratio of the focal length of the objective lens to the focal length of the eyepiece is usually used to calculate the magnification of the angle of view of the telescope. For example, a telescope with a magnification of 10x is a telescope that can magnify a target with a 1-degree angle of view to 10 degrees.

2. Field of view.

Field of view) is marked with the visual range of the product at 1000 meters, such as 126m 1000m, which means that it is 1000 meters away from the observer, and the telescope can observe the field of view within 126 meters.

3. Exit pupil diameter.

is a parameter that roughly describes the brightness of an image. In low-light environments, the larger the diameter of the exit pupil, the clearer the image. The maximum human pupil, under normal physiological circumstances, will not exceed 7mm, so the diameter of the exit pupil greater than 7mm is inadvertently a waste of light.

This parameter does not fully reflect the quality of the telescope.

Because of this parameter, as long as it meets the manufacturing specifications, the numerical requirements can be met. The larger the diameter of the exit pupil, the more suitable it is for use in bumpy environments, and the more stable the observation picture will be, so telescopes such as 7x50 are mostly suitable for use at sea.

This value can be calculated by dividing the objective diameter by the magnification.

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The telescope can be selected by the following factors:1Application ScenariosDifferent application scenarios require different telescope magnifications.

For example, the observation of birds and wildlife requires a large multiple, generally around 8-10 times. The starry sky requires smaller multiples, such as 4 or 6x. 2.

The farther away the target is from the target, the higher the magnification of the telescope is required. Generally speaking, the higher the multiplier, the farther the viewing distance. 3.

Optical QualityOptical quality determines light transmittance and field of view clarity. When choosing a high magnification lens, choose a telescope with better optical quality. To sum up, the selection of telescope magnification needs to consider the key plexus according to the application scenario, target distance and optical quality.

Usually choose a multiplier between 4-10x to meet most needs.

The magnification of a telescope refers to its ability to magnify an object, and generally refers to the ratio of the aperture of the lens barrel to the focal length of the objective lens. For example, a telescope with an aperture of 50 mm and a focal length of 500 mm will have a multiplier of 10 times. However, it should be noted that the higher the magnification of the telescope, the better its observation effect is good, because the telescope with high magnification is susceptible to vibration and jitter, and the observation stability is low.

At the same time, the magnification is also related to the telescope, and the telescope with high magnification is usually higher.