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.EOS M3 test data on DxO Mark EOS M10 test data on DxO Mark
DSLR image quality & resolution in a mirrorless body; Higher-res 24MP APS-C sensor; Much improved AF performance; Better ergonomics with full PASM dial; Built-in Wi-Fi & NFC; Tilting LCD.
No built-in EVF; Limited native lens selection; Slow burst mode; Shallow buffer depth with RAW files; No 60p video frame rate or 4K video option.
User-friendly design; great touchscreen interface; good image quality
No viewfinder; limited physical controls; sub-par continuous shooting; lacking video features