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 II test data on DxO Mark
New, 20.2MP, 1-inch type, backside illuminated (BSI) image sensor produces superb image quality, with particular improvements in low light and high ISO; 3-inch tilting rear LCD screen handy for composing shots from difficult angles; Fast all-around performer with quick autofocus and virtually no shutter lag; New, multi-interface hotshoe for adding a strobe or optional electronic viewfinder; Built-in Wi-Fi with NFC.
Bigger and heavier than previous model; More expensive than previous model; Reduced burst performance when shooting RAW files; Somewhat confusing menu structure and control layout; Wi-Fi features can be difficult to set up.
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