Sony A7R II Fisheye alternatives

I think it would be premature to assume that the 180mm port won't work with this lens and adapter combo, the 140mm is just the better port choice because of its size.

I have one manual lens (15mm) for shooting out of water and so far the focus peaking has worked quite well. I hope to test this with the Nikonos 15mm at some point.

Focus peaking works fine with the Nikonos.

I've written a review of the A7II (not R model) and Sea & Sea Housing system on our blog here. (Note; I've made some edits to it this morning 9/9 to clarify a couple of technical points.)

My bottom line is that for stills it's good system, but not as good as my D800. For the cost and size of the system after adding in the large full-frame lenses and ports, I just don't see why you wouldn't want to just shoot a full-frame DSLR. In the water, the size difference is small and I didn't find the dynamic range and sharpness to be as good. Phil and I diagree on these points.

I think the A7IIR is a potentially great video camera though.

If I wanted a smaller system, I'd go with the E-M1, it shoots at least as good as any cropped frame DSLR in my book and is much smaller and less expensive.

I Jack, I think you may have miss read some of my posts. My comments regarding Sony a7 II and A7R II v. full frame DSLR were mostly confined to the 16-35mm lenses and associated ports. With the Sony FE 16-35mm the recommended Nauticam port is the 180mm (the same port used with Olympus 7-14mm M43) with ports using the same zoom range for DSLR 220mm to 240mm is the norm with no real increase in image quality over the smaller Sony system.

Reference Sony V. DSLR's like D810 my comments were confined to DXO marks rating of sensors which are both excellent in every regard. I agree that the Olympus E-M1 is an excellent mirrorless system. I have been using one for years and still own the system which has excellent image quality for its sensor size. I think its is clear that for overall image quality the A7R II is the best mirrorless camera made at this time and also an excellent video camera. For many traveling photographers this will be a hard combination to match in one mirrorless camera system.

I Jack, I think you may have miss read some of my posts. My comments regarding Sony a7 II and A7R II v. full frame DSLR were mostly confined to the 16-35mm lenses and associated ports. With the Sony FE 16-35mm the recommended Nauticam port is the 180mm (the same port used with Olympus 7-14mm M43) with ports using the same zoom range for DSLR 220mm to 240mm is the norm with no real increase in image quality over the smaller Sony system.

Phil, I shoot my Nikon 17-35mm in a 170mm dome on the D800 all the time. Yes, you need to "work" with the corners, no question, but I don't find it terribly limiting. The Sigma 15mm FE or the Nikon 16mm FE fit many smaller domes like the 170mm (or even smaller) without any extension. The Sony a7II has the new 28mm lens plus the lens converters to get to 16mm, but it is a large assembly and requires an adapter and extension to house - and there goes much of your size and packing advantage.

I agree, it promises to be a great video camera though, but for me, for stills, I just don't think you can beat a DSLR - at least for full-frame.