I use a Nikon AF-105-VR almost exclusively. It has a 6-7" working distance (Distance from the end of the lens) to get 1:1. A subsee adapter will give 2.25:1 at a workind distance of about 3", somewhat less if you back up just a bit.
Here is a Bubble Coral Shrimp at more than 1:1. It is full frame. (I am not sure of the actual magnification but it is better than 1:1.) What is nice about this shot is that it is still a shot of the critter and the environment,
Thanks Tom. Nice shot! I have a Nexus CL-100 wet mount close-up lens that works fine with the 105mm when shooting objects that do not move much but limits the distance when I'm shooting skittish fish, like goby and blenny. That's why I'm thinking of getting the teleconvertor (double the magnification w/o limiting the lens distance from the object).