RAW files are not quite ‘digital negatives’. They are actually more like the latent images on undeveloped film and need a ‘digital developer’. Choosing the best digital developer (RAW processing software) can make a big difference to your images.
Cameras use 'color filter arrays', or tiny color filters, over each photo site so that it can capture red, green or blue color information. Demosaicing is the rocess where the camera (or RAW conversion software) takes the ‘mosaic’ of red, green and blue pixel data from the sensor and converts it into full-color information for each pixel.
RAW files explained
Many photographers prefer to work with RAW files – but what are they, how do you work with them, and why are they so much better than regular in-camera JPEGs?