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 A7R 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
Incredibly small body for a fully-featured, full-frame camera; Resolution that rivals a medium-format camera; Excellent image quality even at very high sensitivities; Decent performance bearing in mind its extremely high resolution; Accepts existing Alpha-mount and E-mount lenses, and can optionally crop to APS-C image circle.
Extreme resolution makes focus and lens quality critical; Modest performance; Loud shutter; Lacks hybrid autofocus of the A7; Mediocre battery life when using electronic viewfinder; Slow X-sync; Limited selection of native Sony FE lenses.
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.