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.D5100 test data on DxO Mark SL2 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.
Higher resolution and better image quality than SL1; Much improved dynamic range; Excellent Dual Pixel CMOS AF; Compact body with improved ergonomics; Articulating touchscreen; Full HD movies up to 60p; Better battery life.
Shallow buffer depth with RAW files; Dynamic range and high ISO performance still not as good as leading competitors; No 4K video option; OVF only offers 9 AF points.