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.D5500 test data on DxO Mark 80D test data on DxO Mark
Amazingly small for a DSLR; Great image quality for its class, including superb low light and high ISO performance; Generous JPEG buffer depth; High resolution.
Buffer depths are shallow when shooting RAW; Lacks GPS from the predecessor; No AA filter means it's susceptible to aliasing artifacts.
Very good image quality; Better RAW high ISO performance than predecessor; Improved buffer depth; Very fast AF; Dual Pixel CMOS AF is excellent; f/8 AF support; 1080/60p video; Headphone jack; Very good battery life.
New kit lens isn't very sharp; No 4K video; No clean HDMI out; 29:59 minute video recording limit; Phase detect AF not as sensitive in low-light as expected (Dual Pixel AF is better in low-light).