We use a Nikon D610 with a Nikon 105mm lens. Settings are usually around F11 - 160/s - 1000ISO. These pictures are taken very fast too I'm not trying to take amazing pics, just clear photos to sell corals. If you have a tripod and take your time you can get MUCH better pics with this setup.
If you're on a budget the Tamron 90mm is just as sharp but the autofocus is subpar compared to Nikon.