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.M-P (Typ 240) test data on DxO Mark X100 test data on DxO Mark
Superb image quality; Dazzling Hybrid Viewfinder; Traditional mechanical controls; Mostly excellent optical performance.
Quirky interface; Manual dials turn easily; Manual focus is too difficult to use; Dramatic lens flare, especially at night.