Some of my first photos with A6300

I tried the diopter on the recommendation of the shop that sold me my underwater gear. Specifically it was recommended for the 16-35 behind a 230mm dome port. I think the idea was to decrease the minimum focus distance so the camera would focus on the virtual image created by the dome. Or so I thought. It was all supposed to help the corners and edges. Maybe it did, but if so they went from crappy to slightly-less-crappy.

The Internal Correction Lens on the other hand was a wonder. It was advertised as creating an image equivalent to stopping down two stops. I think it is better:

After lugging the 230mm dome port along on dive trips for 3 years, I finally have shots that seem worth it.

It's only made in two diameters and is aimed pretty much at the 16-35 lens, a 230-240mm dome port and a 90mm extension. It sure works.

On the TC, I'm pretty aware of the technology involved and the tradeoffs. A loss of light isn't one of them. Wide open my F2.8 lens becomes F4.0, but I typically shoot it at F10-F16 or higher. I knew it would affect my focus speed, but when I tried it I was also using my D850 for the first time. I think it was kind of an even trade for AF speed - the 105 with 1.4tc on the D850 focuses about as well as the bare lens does on the D810. So I can feel the loss of speed, but it's not a huge deal. What killed it for me was the softening of the image. Now I'm looking into a 150mm macro lens, if I can find a suitable port for it.