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.A9 test data on DxO Mark A7 II test data on DxO Mark
Cameras with longer battery life can take more photos before exhausting their batteries.
Special note: The measurement standard for battery life stipulates that if a camera has an internal flash, it must be used for 50% of photos taken. For this reason, comparisons of one camera with an internal flash to another without will not be comparable
Excellent 5-axis sensor-shift image stabilization; Sensor-shift IS brings stabilization to nearly any lens; Much-improved ergonomics and top-deck control layout; 'Mark II' maintains same impressive image quality, dynamic range and high ISO performance; XAVC S 50Mbps video format; Faster start-up time; Hybrid AF performs well with good continuous AF.
(Similar to A7): Loud shutter (but electronic first-curtain helps); Battery life could be better; Low-light AF still not as good as most DSLRs; High ISO JPEGs look over-processed; Slow buffer clearing; Limited selection of native Sony FE lenses (but it's getting better).
New sensor offers incredible performance; Excellent image quality at low & high ISOs; Very good dynamic range; Phenomenal 20fps burst speed & deep buffer; Very good battery life for a mirrorless; 4K video; Dual card slots.
Slow buffer clearing; Only one UHS-II card slot; Touchscreen underutilized; No lossless RAW compression option; No 4K/60p option.