Get Nikon 20mm f/1.8 at B&H Photo.
In my review of the Nikon 20/1.8G in DAP. It complements Glacial Erratics in Blue Skylight, Westering Sunstar.
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.
The 20/1.8G is a fine lens and I now comfortable recommending it as the best wide angle Nikon offers. At about $797, it’s a steal for what it delivers.