Canon announces a number of improvements in its camcorders image sensors:
"The HD CMOS PRO sensor has evolved for the 2012 range, with refinements to the
micro lens and colour filter to allow light to be collected more effectively. An antireflection film has been added to each micro lens on the sensor whilst the colour filter material has been upgraded to a higher transmission one. The resulting low-light
performance of the sensor is 20% more effective than the HD CMOS PRO sensor
currently deployed in the HF M-series."
The large 14.3MP 1.5-inch PowerShot G1 X sensor is said to utilize on-chip noise reduction technology and has 4 channel read-out for high speed.