Why is the aperture too large or too small to reduce the image quality?

The reason why the night scene is shot with a small aperture is because the image quality is fine and the resolution is high, but it is not too small, that is to say, compared with a large aperture like 2.8, the reason is that the light aberration near the optical axis of the lens is small. Within a certain range, it can be considered that there is no obvious difference, but the difference caused by large aperture and sufficient light during the day is not obvious. At night, night scenes are usually taken of tall buildings and bridges with obvious light contours. If the big aperture is at this time, there will be no small aperture. Tired that there is no slightly smaller aperture, because the aberration caused by a large aperture outside the subject is much more black at night than during the day. Of course, it doesn't matter if you use a tripod. The exposure time is long with a small aperture. If you don't use a shelf, you can only open the aperture to improve the sensitivity, but this is only if you capture the picture or have low requirements for the picture.