I use microscope lens adapted to my camera, and a technique called "Focus Stacking", where you take a number of pictures, each with a very shallow depth of field, and with a difference in the distance to the subject between each shot. After that, all the images are "merged" in a specialized program, that only takes the focused part of each image, as a kind of scanner. The resulting image has a depth of field impossible to achieve via normal techniques (like closing the diaphragm). HTH.