Urgent!! Tourist telescope problem. About telescopes!

Regarding magnification: each telescope is marked with the main parameters, such as 7x35 means that the mirror is 7x, and the objective lens aperture is 35mm. Generally, less than 6 times is a low magnification, 6 10 times is a medium magnification, and more than 10 times is a high magnification.

In fact, the reasonable magnification of a telescope is related to the aperture of the telescope and the way of observation: if the aperture is large, the magnification can be appropriately higher, and the fixed observation with a tripod can be higher than the handheld observation. If you buy binoculars for hand-held observation, 7 10 times is enough, the highest should not exceed 12 times, otherwise the higher the multiple, the smaller and darker the observation field of view, the observation effect will decrease, especially the jitter brought by high magnification is also greatly increased, so that the observed scenery can not be stabilized, and it is difficult to observe normally.

About aperture: the larger the aperture, the larger the observation field of view and brightness, which is conducive to observation in low light, but the larger the aperture, the larger the volume and weight, and the higher the cost, which can generally be selected between 30 and 50mm according to the need.

To sum up, I see that you bought Boguan, because considering your ** requirements.

It is recommended that you buy Boguan Hunter 7x50 or Boguan Hunter 8x40, which are good.

If the product of the same grade:

45 caliber, it is not easy to carry, but it is a little more comfortable to use.

The 21 caliber is not as comfortable as the 45 caliber, but it is very easy to carry.

The brightness of the 45 caliber is slightly better.

If at the same level, it is far less obvious than what you said: "Look at a person's face, 8 21 can see the general outline, and 8 45 can see the details".

The difference in resolution between the two specifications is subtle. In fact, just think about it, if the difference is so obvious, then portable products would have been eliminated long ago.

The really obvious difference, in fact, you have already said, is brightness, which, by the way, can also be described in another word "comfort".

If this product is very different from the 8x45 one (I probably know which one you asked), it is because of the different grades :)**Several times more :)

The difference in aperture has a great impact on astronomy, mainly because astronomical telescopes are mainly used under the limit multiple of the objective aperture, that is, the diameter of the exit pupil is very small, and at this time, the aperture is larger, and the improvement of image quality is indeed more obvious.

But in hand, it is still more obviously different. The difference between sharpness and caliber on the hand is not obvious, and the main description is that "comfort" is more accurate.

The difference between the light transmission of 45mm and 21mm is nearly doubled, and if 8 21 can see the general outline of a person's face, then there is no problem with switching to 8 45 to see who this person is. The most critical parameter of a telescope is the light force, or aperture.

For example, if you use an 8 45 telescope at night, you can see a darker scene, but if you use 8 21, it will be dark.

The advantage of a large aperture of a telescope at the same magnification is that in addition to higher brightness, the exit pupil distance will also be longer, which means that the eyes can see the full field of view without pressing close to the eyepiece, and it will be more comfortable to see. In addition, even with the same magnification, the telescope resolution of a large objective will be better.

There is not much difference between daytime use and if it is dim or low-light, it can be compared.

The bigger the mirror, the more concentrated it is, a matter of common sense.