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.K-3 test data on DxO Mark A77 test data on DxO Mark
Very fast top frame rate; full-time phase-detect autofocus; Full 60p HD video; Excellent kit lens; Very good high-resolution sensor.
Heavy; EVF appears dim when used in bright light; AF tracking in Movie mode was unreliable in our testing.
Top-notch image quality; Great ergonomics in a compact body; Unique on-demand low-pass filtering; Broad sensitivity range; Large and bright viewfinder for an APS-C camera; Dual card slots; Optional Wi-Fi remote control
AE Lock button is poorly located; Below-average battery life for a DSLR; Rather dated-looking menu system; Requires a different battery grip accessory than its predecessors; Less third-party support than some rivals