We compare the performance of competing CCD and CMOS imaging sensors including backside-illuminated devices. Comparisons are made through a new performance transfer curve that shows at a glance performance deficiencies for any given pixel architecture analyzed or characterized. Called lux transfer, the curve plots SNR as a function of absolute light intensity for a family of exposure times over the sensor’s dynamic range (i.e., read noise to full well). Critical performance parameters on which the curve is based are reviewed and analytically described [e.g., quantum efficiency (QE), pixel nonuniformity, full well, dark current, read noise, modulation transfer function (MTF), etc.]. Besides SNR, many by-products come from lux transfer including dynamic range, responsivity (e-/lux-s), charge capacity, linearity, and International Organization for Standards (ISO) rating. Experimental data generated by 4 ?m, three transistor (3T) pixel digital video graphics array (DVGA) and a 5.6-?m, 3T pixel digital extended graphics array (DXGA) CMOS sensors are presented that demonstrate lux transfer use.