At ISO 200 400 also totally clean , merest hint rising noise.To fair , yet impinge upon images visually without good deal pixel-peeping.At ISO 800 1600 , images still used confidence , start mild chromatic noise.At ISO 3200 obvious mild noise creeping , crisp looks reasonably good.At ISO 6400 noise level rising , still sharp unpleasant purple hue taking darker areas.Maybe clue ISO 6400 highest value camera dial enter extended menu values camera basically loses it.ISO 12800 good , purple noisy.ISO 25600 bring Jimi Hendrix feel images noise grows Purple Haze.Not usable except extremis.Finally , ISO 51200 beyond horrible hardly usable all.ISO figure noise starts become visible : ISO3200 ISO figure noise overwhelms image : ISO12800 Interested ?