Noise high ISO51200 , settings best avoided.Noise reduction options include Off , Low , Normal , High , default Normal.These photos taken default settings.ISO figure noise starts become visible : ISO6400 ISO figure noise overwhelms image : ISO51200 Interested ? Help support ePHOTOzine using links.Amazon UK Amazon US Nikon Z9 The Z9 top-of-the-line professional workhorse rapidly growing number superb lenses support it.ISO performance impressive.We find point noise becomes much , general , perhaps principle could sharp noisy image better woolly noise-free one.Images Z9 clean right ISO 3200.By ISO 6400 start see noise taking hold , even ISO 12800 images usable.ISO 25600 tipping point extended values ISO 51200 102400 still emergency use .