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.E-P1 test data on DxO Mark V3 test data on DxO Mark
Very compact for an interchangeable-lens camera; Generous kit includes lens, high-res electronic viewfinder and accessory grip; Good image quality for the sensor size; Amazing burst performance; Lightning-fast autofocus; Intuitive touch-screen makes focusing a snap
Smaller sensor than most rivals limits possibilities for available-light shooting; Program mode opts for wide-open aperture most of the time; Limited dynamic range; Noisy shadows; Below-average battery life; Pricey when considering its image quality