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.D800 test data on DxO Mark D7100 test data on DxO Mark
Rugged build; Excellent controls; Extremely high resolution; Dual cards; Surprising high ISO performance.
Very large files; Slower frame rate; Custom white balance gives a greenish tint; Battery life lower than D700.
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).