IIRC a typical implementation of electronic global shutter for CMOS sensors requires one extra transistor per each pixel to "lock" the charge. As for why it's n

IIRC a typical implementation of electronic global shutter for CMOS sensors requires one extra transistor per each pixel to "lock" the charge. As for why it's not being done outside specialised sensors: not many people are concerned about this problem, they are more concerned about other parameters of image sensor.