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.D5300 test data on DxO Mark K-3 test data on DxO Mark
Top-notch image quality; Great ergonomics in a compact body; Unique on-demand low-pass filtering; Broad sensitivity range; Large and bright viewfinder for an APS-C camera; Dual card slots; Optional Wi-Fi remote control
AE Lock button is poorly located; Below-average battery life for a DSLR; Rather dated-looking menu system; Requires a different battery grip accessory than its predecessors; Less third-party support than some rivals
Excellent image quality similar to more expensive DSLRs (like the D7100); Great dynamic range; Responsive all-around performer; Excellent Full HD video-shooting quality; Built-in Wi-Fi with remote control and sharing features; Built-in GPS; Compact and lightweight size; 18-140mm kit lens performs well for its type and has a very versatile focus length range.
AA-filterless sensor makes it more prone to moire; Burst speed slows with highest quality 14-bit RAW images; Live View mode not as good as some competitors; No external headphone jack; GPS receiver not very sensitive.