- High ISO is useful especially when working in low-light conditions. High ISO 800, 1600, or 3200.
The High ISO has much more noise, i.e. more level of noise (graininess and blotchy colors).
For certain types of sports and action photography, a high ISO might be your only option.
to pick a sharp photo at a high ISO.
Ref - https://photographylife.com/what-is-iso-in-photography