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.5D Mark IV test data on DxO Mark D7100 test data on DxO Mark
Solid, ergonomic body design; Stunning, highly detailed photos, thanks to 24.1MP sensor upgrade and removal of optical low-pass filter; Cool 1.3x crop mode extends reach to nearly 2x the full-frame equivalent; Records Full 1080p HD video at up to 30fps with full-time AF; Many pro-level features packed into a consumer-friendly body at reasonable price.
Shallow buffer that hampers continuous burst shooting; AF slightly slower than average for its class; No real-time aperture control while in Movie mode (among other quirks); More noticeable moire patterns and aliasing artifacts (but only found when shooting fabrics with strong, distinct patterns).
Superb image quality from RAW files; Improved dynamic range; Excellent high ISO performance; Fast 7fps burst rate with unlimited JPEG buffer; High-quality cinema 4K video; Built-in Wi-Fi; Dual Pixel CMOS AF is very good.
JPEG files look soft at default settings; 1/200s flash sync; 4K video codec is cumbersome; 29:59 continuous video recording limit.