A six-shot image will produce a Tiff file that takes up roughly 600 MB for each image. The way it works is actually pretty clever. When the sensor moves over by a pixel, each pixel is now under a different color filter in the Bayer array. So, with each shot, each pixel is picking up specific color information about a scene. Because of this, the camera doesn't need to interpolate to compensate for each pixel only recording one color. In a way, it's similar to how Sigma's Foveon sensor records data for each color at the same time.