JPG format compresses the image every time you open it and save, thereby increasing the loss of shade.
The visible spectrum full is not reproducible and the color, rather than seen, is perceived.
What we can take pictures, view and print only a part of the visible spectrum.
exposure of the picture depends on the combination of aperture and exposure time and is influenced by the sensitivity setting on the camera.
The exposure time measured in seconds or fractions, is the time during which the camera shutter remains open and allows the light reaching the sensor.