Sony's established semiconductor expertise is behind the exceptional performance of the α850 in many ways, but perhaps most prominently in its full-frame 24.6-megapixel Exmor CMOS image sensor. This sensor – the same one used in the flagship α900 – was designed specifically for 35mm full-frame imaging, implementing proprietary Sony planarization technology for maximum flatness, plus over 6,000 on-chip column parallel analog/digital converters so that the analog image is converted to noise-resistant digital form right at the beginning of the processing chain. Noise reduction is applied both before and after analog/digital conversion for an even cleaner signal.