As the magnification increases, the field of view will gradually become smaller, the sharpness and brightness of the picture will decrease, and the influence of external weather factors will increase. As shown in the experiment, as the magnification of the telescope gradually increases from 20x to 60x, the field of view gradually becomes smaller, the sharpness of the picture decreases, the brightness also becomes darker, and the influence of external weather factors such as air waves becomes greater and greater. This shows that in the actual use of high-magnification telescopes, the smaller field of view will lead to a limited observation range, while the reduction of picture indicators and the increase in the influence of external factors will reduce the observation effect.
The chromatic aberration will gradually increase, and after reaching a certain value, it will offset the advantage of high magnification. High-magnification telescopes are often more prone to chromatic aberration problems because they require higher optical performance. As the magnification increases, the chromatic aberration gradually increases. When it reaches a certain value, it will make the observation effect worse, offsetting the advantages brought by the high magnification.
The higher the magnification, the worse the stability, the greater the influence of breathing, pulse beating and air convection, and the greater the jitter. When holding a high-power telescope, if the power is too high, the breathing, pulse and air convection will have a greater impact on it, and the resulting jitter will make the image blurry and difficult to see clearly. Even for a telescope placed on a tripod, the power is limited, because the uneven density of the atmosphere will cause the image to be blurred, and the higher the power, the more obvious the blur.
The smaller the actual field of view, the smaller the observation area. Generally speaking, the larger the power, the smaller the observation area. Many friends think it is because of the eyepiece. In fact, even if the eyepiece can keep the viewing angle unchanged when the focal length changes, the field of view will be reduced inversely proportional to the magnification due to the reduction in the observation area.
The lower the brightness, the greater the power, the lower the brightness of the telescope under the same objective lens aperture. For example, with a 50mm aperture and a 7x magnification, the field of view will be larger than that of a 15x, and the eyes will be very comfortable. Under certain objective lens aperture conditions, simply increasing the visual magnification will not see more details, but will only reduce the subjective brightness, so it is meaningless.
The atmosphere and other observation conditions limit the maximum magnification, and the clarity and magnification effect are affected when the weather is bad. When the weather is bad and foggy, it will definitely affect the clarity and magnification effect, while the observation effect will be much better when the weather is clear. This shows that unsatisfactory observation conditions such as the atmosphere will limit the maximum magnification of the telescope.
If the magnification is too large and exceeds the theoretical resolution limit, it will cause invalid magnification. In theory, the resolution of a telescope has a limit of 140 mm of aperture, in arc seconds. After the magnification is too large, due to this theoretical limit, no more details will appear when magnifying, so it loses its meaning.