I am engaged in aquarium photography of small colourful shrimp measuring between 10-20mm in length. With a new camera, the D810, I have tried some slightly different options. One set consists of Nikkor 105mm 4.0 AiS with a K3 ring and an P-Nikkor 105mm 4.0 for bellows, two classics in other words. That solution is quite sharp and the viewfinder is bright so the focus is easy to adjust. The picture of the green shrimp is taken with this combination. ISO 64, 250 / sec. Aperture 16. A working distance of approx. 10cm.
The next picture of the red shrimp in the moss is taken with Zeiss 135mm 2.0 which has a close-up of 80cm. But using a polaroid close-up lens, Polaroid 250D, the same as Canon's equivalent, and some cropping. The depth of field is always a problem. ISO 64 320 / sec. Aperture 16. Both images taken with two studio flashes. A really crisp macro of 90-100mm would be nice to try!
flic.kr/p/Ww3wq8
flic.kr/p/Wdq4vh