An astronomical telescope for observing galaxies

This is my previous answer. Of course, the first part also includes the effect of observing galaxies with home astronomical telescopes. Please read it.

Look at the Andromeda galaxy, you will be disappointed, because the photos in Stargazing at Night show that the Andromeda galaxy with a diameter of 200 mm is an oval fog with few details. 250 mm telescope, you can see the cantilever trace of the galaxy M5 1.

The reasons are as follows.

As for the nebula galaxy, the effect can be seen in photos on the Internet and in magazines. First of all, the telescope they used was very large, and they found a place with little light pollution (people may see more than 2,000 stars with little light pollution, and the place without street lights in your backyard is certainly much worse than this).

However, even in a 406 mm telescope (64 times larger than yours), you can't see the effect in the photo. This is because the photos of nebulae and galaxies are taken by camera exposure for a few minutes or even hours, while the human eye seems to generate a photo every 0.5 seconds. When the light is very dark, people can only perceive the light and shade, but not the color. (Visual cells are divided into cone cells and rod cells, because cone cells that can feel color can't be activated in dark conditions, while rod cells that can feel light and shade can work in dark conditions, so the dark nebula galaxies you see are black and white)) So there is such a contrast in the Guide to Astronomical Observation Time in the Night Sky: the photos of lagoon nebula taken by a telescope with a diameter of 152 mm are in color.

I haven't seen Saturn, but I have seen Jupiter. 60 times, you may want to see the effect in the magazine. As a result, I saw a ball with a diameter of 2 mm (if placed at an arm's length from you). I can hardly see any details in such a small situation. It took me a long time to see the black lines drawn by the two thinnest neutral strokes. This may disappoint you, but it's true. Say this, maybe your heart is broken, but it's true. So my advice is, don't buy astronomical telescopes. Buy it back (like my 50-caliber telescope), and you will definitely be disappointed and even regret it.

But I know you still want to buy an astronomical telescope. It's no use talking so much. I really don't recommend that you buy all kinds of astronomical telescopes (such as this one. It's really cheap, but you can't even see the most obvious details of Jupiter, let alone the nebula galaxy.

However, if you really want to buy a telescope, I will remember the special recommendation (if you can get 50 yuan) and go to the online store to buy a guide to astronomical observation time at night. This is a magical book, which will provide you with a lot of useful information and, more importantly, teach you a lot of useful knowledge. Most of what I gave you was extracted from it. Buy it back, I promise, it's worth it.

When buying a telescope, it is often easy to ignore the bracket. Think about it. When you use the fine-tuning device 60 times, your hand slightly shakes the fine-tuning device, and it will be magnified 60 times. If you want the celestial body to go to the center of the field of vision, the celestial body will go straight out of the field of vision. Be sure to buy a stable bracket when you buy it.