I want to ask you, what may be the reason why the pictures I took with a 60D camera feel poor in quality?

The quality of photos is affected by many factors:

1 Weather conditions: If it is cloudy or in other poor lighting conditions, the picture quality will basically not be good.

2 lens situation: the quality of lens A itself is average, obviously the cheap lens 18-55 itself is useless. Install other lenses (including uv, polarized light, filter, color filter, etc.). ) in front of lens b will have an impact on imaging. If the lens quality is not very good, the loss will be even greater.

3 Other situations: For example, in the case of a specific shutter speed, a tripod is needed to ensure the image quality.

In fact, there is another important influence on the image quality: the higher the aperture ratio of the photosensitive element on the back of the machine, the worse the image quality will be. To put it simply, the higher the pixel, the worse the imaging quality when the size of the photosensitive element is the same. See clearly, this conclusion is not the other way around.