ISO is the parameter that defines the light sensitivity of a digital camera sensor. The sensitivity of digital cameras is expressed in dimensionless units equivalent to the sensitivity of film cameras. However, due to the different physical principles of capturing light, there is no direct relationship between them.
ISO is a parameter of the digital camera sensor
Every digital camera sensor has a minimum and maximum ISO value that can be set. These values can be set manually or automatically by the camera based on the lighting conditions of the current scene.
The lower the ISO set when shooting, the more light the camera needs and the less digital noise there is in the final image.
The higher the ISO set when shooting, the less light the camera needs and the more digital noise there is in the final image.
Since digital noise is highly undesirable in high-precision aerial photography, it is recommended to set ISO to the minimum values.
Native ISO is the camera's standard sensitivity setting at which the noise level is the lowest