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.A7 III test data on DxO Mark D5100 test data on DxO Mark
Side-mounted tilt / swivel LCD screen; same sensor and processing as the Nikon D7000; good speed and battery life; in-camera HDR and filter effects; Full HD video capture with aperture control; audio levels control and external microphone jack.
AF-S lens mount doesn't offer autofocus with screw-drive lenses; popup flash isn't the greatest; no built-in wireless flash control; HDR function doesn't microalign source images.
New 24MP sensor offers excellent image quality; Outstanding high ISO performance and dynamic range; Improved JPEG colors; Improved build quality; Fast autofocus; Excellent 4K video; Very good battery life.
Buffer clearing can be slow even with fast UHS-II cards; UHS-II support only on one card slot; No losslessly compressed RAW option; Dedicated battery charger not included; Menus are still confusing; No built-in flash.