My first post here after reading you guys for a while but it seems there is no other topics related to the same problem I have. I'm using Olympus C-5050Z with Olympus PT-015 housing, Inon D-180, Inon UWL100 + Dome. I am having problem with UWL100 + Dome. When I use it at the max wide angle zoom, all the shots taken will have a small dark corner at the bottom left of all shots. With the normal horizontal shots with reef at the bottom, it's quit difficult to spot that but with vertical shots of big blue background, it's easier to see. The sample here are from my first time using this Inon dome lens in Maldives. Now this problem is still there, I only avoid it by not using it at the widest angle of camera. Is there anyway I can fix this problem? Please advise. Thank you.