What aperture is suitable for photography?

You only know that F8 is easy to use, but you should also know that aperture, shutter speed, ISO and other values are absolutely related. In a changing environment, it is definitely not possible to use only one aperture/shutter combination. Assuming that the front of a person is photographed in clear sunlight, under the condition of ISO 100, F8 should probably match the shutter speed of about 1/400 s ... On the cloudy day of F8 ISO 100, the shutter speed will be reduced to about 1/300s. There are many similar examples. When setting the aperture shutter combination, it must be based on the actual situation of the scene and the shooting intention. If you don't have full manual experience and insist on using the "best aperture" of F8, then it is recommended that you use the aperture priority gear (the first gear of D90) and the central focus metering, which can cope with most situations during the day.

If you want to improve your skills, please try M file as much as possible and take the course of New York Photography Institute. The combination of aperture and shutter is a big proposition, which involves many factors and needs to be learned slowly.