How your camera captures picture

Your Canon camera captures and processes images in four main stages. Stage 1 is where the photosites on the sensor are exposed and register an analogue light value, which needs to be converted into digital data as part of the signal processing that happens in Stage 2. This produces a Raw file in Stage 3, which is what we want! Otherwise, the camera will go on to Stage 4 and process this data into a JPEG file.