These corals when out feeding look very much like anemones as they seem to be all tentacles. In the upper left corner you can see a couple of cups with the tentacles only partially out. The cup is hard and is all that is seen during the day or at least in daylight. This image was taken in the afternoon but under a dock where it was dark. The cups are about 1/2 inch in diameter and the “blooming” or feeding tentacles are about an inch across.
This image is very dramatic in all sizes and is available in cards.