Hello Everyone!  Really happy to be here and learn from you all.  So I am looking to get a wide angle or fisheye lens for my Sony A7iii.  I have been told many things like the Sony 16-35 f4, Canon 8-15, Sigma 15 f2.8 fisheye.  The Sigma would be the least expensive and I was wondering if any of you Sony users have used it under water?  If so, which adapter did you use? My next choice would be the Sony 16-35 f4 since it is the most versatile and it seems like everyone says that wou