Kim:Koh Bida, Thailand.
We've dived the same spot! Although I've only dived there in bad visibility and no juvenile emperor angelfishes. I have seen some at the Similans, but never had luck with camera to capture one. Actually I don't even have a good pic of an adult emperor. Plenty of *** pictures as those fellas tend to turn just as I'm shooting but no face shots or sideshots with eyes. Maybe on the next trip I'll get lucky