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-M5 II test data on DxO Mark RX100 III test data on DxO Mark
Pocket-friendly design; Popup electronic viewfinder; Bright lens across the zoom range; Great performance with very fast autofocus; Very high resolution gives lots of detail in good light; High ISO noise levels much better than most pocket camera rivals; Wi-Fi wireless networking
Feels a little unbalanced without an accessory grip; Not as much telephoto reach as its siblings; Noise processing is heavier-handed than in earlier models; Quite pricey for a fixed-lens camera
Excellent handling in a compact, weather-sealed body; Crisp, roomy electronic viewfinder; Image quality that can take the fight to APS-C DSLRs; Unique high-res mode lets it bat far above its weight for static scenes; Extremely fast 10 fps burst shooting, Excellent video feature set
Control dials are easily bumped; Below-average battery life at default settings; Buffer depths for raw shooters are a bit limited; 16-megapixel sensor resolution feels dated; Weak bundled flash strobe