My photos are achieved by carefully lighting an object the size of a pin head inside another object the size of a pea. Once it's lit, I take a sequence of photographs at different focus distances. In microscopy, there is very little depth of field but with a technique called focus stacking we can manufacture depth of field with many many images and software designed to smash them all together to render depth.
Usually my "steps" of focus are 1/40th of 1 mm. Depending on how deep the inclusion is, it can take up to 120 shots just to make the final product.