The sensor matters a lot, even when shooting RAW. A RAW file is not “pure light data”; it’s the digitized electrical signal produced by the sensor. So the quality of the RAW file depends heavily on the sensor’s design and readout.

Key sensor factors include:

• photosite/pixel size: larger photosites generally gather more photons, which can improve noise performance and dynamic range
• sensor design/efficiency: some sensors use light more effectively than others
• sensor technology: different designs, such as Bayer-type sensors versus Foveon, produce different RAW data
• analog-to-digital conversion and read noise: these affect how clean and accurate the captured data is

Color is recorded because the sensor has color filters over photosites (or uses a different layered design like Foveon). Each photosite measures light intensity through its filter, and full-color image data is reconstructed later.

The lens still matters greatly for sharpness, contrast, distortion, vignetting, and aberrations, but it does not replace the sensor’s role. The processor mainly affects how JPEGs are rendered; with RAW, most of that processing is deferred. So when shooting RAW, both lens and sensor matter, but the sensor is still a major part of final image quality.