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.A7S test data on DxO Mark GX-20 test data on DxO Mark
Cameras with more dynamic range allow you to take photos with dramatic differences in highlight and shadow areas while retaining detail in both.
Think of a brilliant sunset on a rocky beach: Bright sunset in the background, with dark rocks in the foreground. High dynamic range means more of the extremes will be faithfully reproduced.
Dynamic range test data courtesy of DxO Mark.A7S test data on DxO Mark GX-20 test data on DxO Mark
Outstanding high ISO performance; excellent dynamic range; 4K video recording (via uncompressed HDMI); XAVC S option for HD video; Slightly improved battery life over A7/A7R; Built-in Wi-Fi & NFC connectivity.
4K video requires expensive external recorder; Sluggish startup time; Loud shutter; Silent Shooting mode hurts image quality; Lacks a built-in, pop-up flash; Limited selection of native Sony FE lenses.