These can be created by high-end and enthusiast cameras and certain Nokia Lumia smartphones. They contain picture data taken directly from the image sensor in the camera prior to conversion to the more compact JPEG format. As such, they contain more picture information and can allow for higher-quality images to be processed later on your computer. They also require specialised software to process them and take up considerably more disk space. The actual format of the data is often unique to the specific model of camera used.
