F8 in photography

Your relationship is actually very complicated.

Assume that the shutter speed is1120s, the aperture is f8, and the sensitivity is 100. If the shutter speed is reduced to 60 f, the sensitivity is 50, and if the shutter 60 f is 16, the sensitivity is still 100. Can you understand this example?

If the parameters you mentioned above need to be demonstrated, you only need mathematical calculation. In addition, I think the above parameter conversion is not necessarily standard, which means that the brightness of the photos taken may be different.