Dual Conversion Gain
A sensor design offering two selectable amplification circuits, one optimised for dynamic range and one for low noise at high ISO.
In depth
The low-gain mode preserves full-well capacity and maximum dynamic range at base ISO; the high-gain mode reduces read noise for dim conditions. The switch happens at a specific ISO, which is why noise can actually decrease when stepping up to that value — a discontinuity worth knowing for any camera you use in the dark.
Examples in practice
A camera switching to high conversion gain at ISO 640 produces cleaner shadows there than at ISO 500.