This is 2 sets of 4 pixel shift images using a tracker and a Sony A7r3.
Pixel shift is a function of the image stabilisation system where the sensor is shifted 1 pixel each image then they are stacked so there are 4 images each of red green and blue pixels. Its quite clever. It results in a 4 x 42.4megapixel image = nearly 160 megapixels and deeper colour.
http://www.pbase.com/gregbradley/image/168251937/large
Greg.