Understanding ISO

                                              

Low ISO

High ISO

                              

ISO stands for international standards organization. It controls the sensitivity to light. Film ISO relates to the sensitivity of them film light, whereas digital ISO relates to the sensitivity of the image sensor. ISO effects the brightness of a photo. If ISO changes, it effects either the aperture or the shutter speed. In this case, the shutter speed changed along with the ISO. When the ISO is greater, the shutter speed can be faster; but, when it is smaller the lens must be open for a longer time in order to let more light it, as it is not as sensitive to light.