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.A7R III test data on DxO Mark A9 test data on DxO Mark
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.