Went to the South Bay Historic Railroad Society. Most of the shoot was akin to microscopic landscape (1/148 scale). This is small enough that large sand would be like hand-sized rocks.
I used a EF 50mm f/1.4 and sometimes a 12mm Kenko extension tube. DoF was a little challenging. Everything was handheld. Light was low, ISO was mostly 1600 and 3200. Almost all shots were done at the minimum focus distance (both with and without the extension tube), typically between 6" and 18", depending on whether the extension tube was used or not. Most shots were around f/4, and, as you can see, it was still fairly shallow.