We have had a great dive/ photography trip in lembeh on dec2014 . the visibility was poor but it wasn't a problem for the macro photography and find critter . This nudibranch was in a famous dive sites,in nudi retreat2 and it was sitting and the rest position on a small stone. the size was around 5-7cm and i have used snoot on my strobe.
Facts about lembeh - nudi retreat 2

• It is in Indonesia
• lembeh - nudi retreat 2 is in the Sulu and Sulawesi Seas.
• The typical depth is 0-20 Metres 0-60 Feet.
• The typical visibility is 3-10 Metres 10-30 Feet.