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.NX500 test data on DxO Mark GR II test data on DxO Mark
Very good image quality with high-resolution files; Excellent high ISO performance with RAW files; Very good dynamic range; Fast AF performance; Compact design with good build quality; Better ergonomics than predecessor; 4K video recording.
High ISO noise reduction too strong; AF struggles in low-light; Buffer depth is shallow with RAW files; No option for EVF; No built-in flash (external one included); 4K Video is cropped with narrower FOV.
Shooting with a wide prime helps you see new shots; Good performance and fast autofocus; Excellent sharp, bright lens; Very customizable; In-camera Wi-Fi works with more than just Android and iOS; Supports Pentax wireless flash strobes
Fixed, wide prime lens isn't for everyone; Cramped controls; Burst capture is slower for JPEGs; Tends too warm under incandescent lighting; Wi-Fi app is poor, and web browser control has cluttered interface