Maximum effective ISO is an estimate of the highest sensitivity at which a camera can capture excellent quality photos.
Cameras with higher effective ISO will be better choices for indoor photography, night shooting, and indoor sports photography, especially if you intend to make large prints.
You can learn more at our glossary entry.
Maximum effective ISO test data courtesy of DxO Mark.T6s test data on DxO Mark GH5 test data on DxO Mark
Highest resolution Canon APS-C camera yet; Good high ISO performance for its class; Very fast autofocus; Servo AF in Live View; Quick Control Dial & top-plate LCD screen.
Shallow buffer depth with RAW files; Below average battery life; No 60p video frame rate.
20MP sensor; Better per-pixel sharpness; Very good, slightly improved dynamic range and high ISOs; Stellar 4K video up to 60p with no crop; 6K Photo; Dual UHS-II SD slots; Good battery life for its class.
Buffer is deep, but slow to clear; Expensive; Menus still confusing; No optical low-pass filter means greater risk of moire; No built-in flash.