Get Nikon 20mm f/1.8 at B&H Photo.
In my review of the Nikon 20/1.8G in DAP is this aperture series at f/1.8, f/2, ... f/13, f/16 which is excellent for showing the performance of the Nikon 20/1.8G under field conditions for a typical near to far landscape scene. It is a nice complement to the Glacial Erratics in Blue Skylight, Westering Sunstar series. Together, a very good insight into the overall performance can be understood.
Includes the f/1.8 - f/16 aperture range in HD and UltraHD sizes in color and black and white, as well as large crops across that full range.