- The characteristics of the color-filter array assemblies are not identical
- The IR layers' frequency response are not identical
- The in-camera JPEG rendering algotithms are not identical
In terms of color rendering aesthetics, a CCD camera can be better than a CMOS camera when the CCD camera benefits from superior IR, CFA and demosaicking firmware design and engineering.
There can be subtle differences in the pinned photo-diode frequency response between CCD and CMOS sensor beds (the silicon wafer the sits behind the color-filter array layer). But both CCD and CMOS pinned photo-diodes produce the same exact thing - electrical charge. Electrical charge not possess aesthetic attributes.
However, differences in the CFA layer frequency band-pass characteristics have a much larger effect. Theses difference affect the spatial array of electrical charge amounts or
Q (coulombs).
For example here's a
comparison of Phase-One IQ3 camera's CFA response versus an unidentified CMOS camera.
Here's a similar
comparison for four different CCD sensor assemblies.
CMOS technology is inherently better in terms of signal capture. However the light that recorded by the CCD or CMOS wafer is not identical unless their CFA and IR filter materials have identical frequency response characteristics.
Raw data demosaicking algorithms are fine tuned to match the camera's CFA frequency response. The goal is for the image rendering model to map directly onto the spatial RGN color information. For in-camera JPEGs, each brand uses a different proprietary imaging engine for products with different sensor assemblies.