Since the iPhone camera has a fixed lens opening, what two main camera settings do you adjust to change how bright or dark your photo looks?

The two main camera settings you adjust to change how bright or dark your photo looks, given a fixed lens opening, are Shutter Speed and ISO. Each setting independently controls the amount of light recorded by the camera sensor. Shutter Speed dictates the duration for which the camera's sensor is exposed to light. It is measured in fractions of a second, such as 1/1000s, 1/60s, or even several full seconds. A longer shutter ....