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.GX1 test data on DxO Mark E-P2 test data on DxO Mark
Appealing design; Good grip; Very good image quality; Fast autofocus; Built-in Level Gauge.
Small rear buttons; Below-average battery life; Weak flash; Orange and yellow can have greenish cast in JPEGs; Shutter-induced motion blur with 14-42mm X Vario kit lens.