Here comes the photographer.

Hi 0.3 is 3200 times 0.3, hi 0.7 is 3200 times 0.7, and hi 1 is 6400, right? You can understand this sentence like this; But ISO 100 is ISO50, which is calculated by multiplying it by 2, which is ISO 25；; 50; 100; 200; 400; 800; 1600; 3200; 6400; 12800。 The sensitivity of the latter stage is twice that of the former stage. In traditional film cameras, ISO stands for the standard of photosensitive speed; In digital cameras, the definition of ISO is the same as that of film, representing the photosensitive speed of CCD or CMOS photosensitive elements. The higher the ISO value, the stronger the photosensitivity of photosensitive materials.