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.D800E test data on DxO Mark D7500 test data on DxO Mark
Rugged build; Excellent controls; Extremely high resolution, even more than the D800; Dual cards; Surprising high ISO performance.
Moire problem with certain subjects; Very large files; Slower frame rate; Battery life lower than D700.
New carbon fiber body is light, compact and very comfortable; Same excellent image quality as the flagship D500; Quick 8.2 frames per second burst shooting with generous buffer; Very fast, accurate autofocus; Tilting touch-screen display; Very good battery life; Records ultra high-def 4K and 60fps Full HD too.
Only a single flash card slot; Doesn't support portrait / battery grip accessories; No rear infrared receiver any more; non-CPU AI lenses will be manual only; 4K video comes with a heavy crop; Movie AF is prone to hunting, Extended ISO sensitivities are a gimmick.