On 5D Mark III’s major technical features:
… what improvements has Canon made to the CMOS image sensor itself relative to the 5D Mark II?
Three main areas of image quality-related improvement on the EOS 5D Mark III image sensor compared to the EOS 5D Mark II are:
· Gapless Microlenses: This feature increases the amount of light received by each photodiode compared to the gapped microlenses used on the 5D Mark II’s image sensor.
· New Photodiode Structure: The photoelectric conversion rate of each photodiode has been improved.
· On-Chip Noise Reduction: Canon’s proprietary technology in this area, which was first shown on the EOS D30 Digital SLR in the year 2000, has steadily improved over the years.