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 M5 test data on DxO Mark NX200 test data on DxO MarkSleek, more professional camera design; faster autofocus system and burst modes; solid performance at high ISOs despite the bump up in megapixels.
Significantly more expensive than previous model; slow buffer clearing with RAW images; with kit lens attached, camera becomes less portable.
Enthusiast-oriented compact camera body; Good image quality in most situations; Built-in electronic viewfinder; Impressive Dual Pixel CMOS AF; Very good overall performance.
High ISO image quality and dynamic range aren't quite up to par with some of its competition; No 4K video recording; Native EF-M lens selection is still limited; Below average battery life.
