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.A6500 test data on DxO Mark NEX-6 test data on DxO Mark
Very good image quality; More consumer-friendly control setup than NEX-7 but more advanced (actual Mode dial) than step-down models; OLED EVF and 3-inch tilting LCD monitor provide viewfinder flexibility; Fast and decisive AF on stationary subjects, and good continuous AF on normal moving subjects; Full HD 1080p video recording at up to 60p.
Hybrid AF system speed and accuracy still lags somewhat behind higher-end DSLRs; Wi-Fi features still rudimentary (join the club); LCD is not a touchscreen; User interface foibles.
Comfortable, premium body with good controls; Touch-screen for subject selection; Hybrid image stabilization system; Excellent image quality; Better high ISO JPEGs than the A6300; Extremely fast 11.1 fps burst capture; Very deep buffers for raw and JPEG alike; 4K video capture with no pixel binning
Pricey for an APS-C camera; JPEG colors aren't the most accurate; Very slow buffer clearing; Laggy touch-pad AF function; Poorly-placed movie button; No headphone jack; Mediocre battery life