The faster the shutter, the faster the speed, but the less light passes.
So the larger the aperture, the faster the shutter can be.
Say it in easy-to-understand mathematics If imaging requires 100 unit of light, if the aperture is 100, then one second exposure is enough. If the aperture is 200 (the weather is fine, the aperture is large, and there is more light passing through), then half a second is enough.
Aperture 50 requires a shutter of 2 seconds. If it is only 1 sec, then imaging is a shadow, or a virtual shadow.
(Of course, in real photography, it is calculated in tenths of a second and hundredth of a second. )
Let's talk about it in a popular way.
For example, shooting moving objects, such as running animals, requires a faster shutter and a larger aperture if you want to shoot clearly, otherwise the photos will be too dark to be clear because of insufficient light.
Shooting at night is the opposite, because the brightness is not enough and the shutter time is long. So if you don't use a tripod at night, there will often be virtual shadows. In fact, simply speaking, it is a virtual shadow caused by insufficient light, and your hands are shaking. Originally, countless virtual shadows should be combined into a real shadow, but it didn't happen by coincidence because of your shaking.
With the flash, although the shutter is shortened and the light is sufficient, the background light is often invisible because it is not sensitive enough to image.
LZ added a question, what will happen if the exposure time is long? The shutter exposure time of some cameras is very long, such as tens of seconds, such as through shutter priority or B-door. Suitable for imaging in the dark, and manual exposure increases the time. I don't know if LZ has seen the photos taken from a height. The traffic lights on the expressway below are in a line, Denghe. This is the shooting technique with a very long exposure time (that is, the shutter). The smaller the shutter, the less light passes through it, so if the shutter lasts for 5 seconds, the car moves 5 meters in 5 seconds, but you can't see the shadows of many cars, but the lights are in a line.
Some lamp players like to use long exposure, such as writing in the air with a luminous laser pointer.
In addition to aperture shutter, there are ISO and other issues. For example, high sensitivity can better image in the dark, but it will reduce the color. On the contrary, in places where the sun is poisonous (such as Maldives), I can take very beautiful photos with 400 yuan's low ISO camera.
Therefore, LZ should try more, such as trying various shutter apertures at a scenic spot and analyzing and comparing them by itself. I got the hang of it.
In addition, digital photography and post-production are also very important.
Photography is mainly the art of light.