Here are some practical examples of photos shot throughout the Sony a6400's ISO range from ISO 100 through ISO 102400.
Sony A6400 with 16-50mm Lens Review
Sony Alpha 6400 E-mount Camera with APS-C Sensor (ILCE-6400M)
Sony Alpha A6400 Review
Sony Alpha a6400 APS-C Mirrorless Camera (ILCE6400/B) - Moment
Sony A6400 Mirrorless camera body
Sony Alpha A6400 Review
Sony A6400 with 16-50mm Lens Review
Sony A6400 Review: Updated with Pro Videographer Comments - Camera Jabber
Sony A6400 Review
Sony A6400 Review
Sony a6100 vs a6400: Which Should You Buy? - Light And Matter
Sony - Alpha a6400 Mirrorless Camera (Body Only) - Black
The Sony a6400 is a Low-Light Beast on a Budget
Sony Alpha A6400 First Impressions Sample Photos
Sony a6400 Review