Raw C2 image, divided by exposure time, half resolution.
C2 "background model" (minimum of 28 daily medians x 4 years)
Resulting image when first image is divide by second image. Dots show where values are taken above the east limb at heights of 2.5, 3, 4, 4.5 and 5 Rsun. These slices are lined up side-by-side to form (in this case) east limb Carrington maps.