For the past year I have been using a Panasonic LX 100 in a Nauticam housing, shooting 4k video and stills with fairly good results. One re-occurring issue that I would like to get resolved is the fact that when visibility becomes less than ideal the shutter release will not activate even though a green light indicates that focus has been achieved. Shooting video is fine and is in focus. Why will the shutter not release when taking stills? Any help or suggestions would be appreciated. Thanks.