It was time to get wet and test the Canon 8 – 15 mm fisheye on the GH5 in the pool so I made my way to Luton Aspire with the help of Rec2Tec Bletchley.

I had the change to try a few things first of all to understand the store coverage of the fisheye frame, this is something I had not tested before but I had built a little model.

This model ignores the corners the red circle are 90 degrees light beams and the amber is the 120 degrees angle. A strobe does not have a sharp fall off when you use diffusers so this model assumes your strobe can keep within 1 Ev loss around 90 degrees and then drop down to – 4 Ev at 120 degrees. I do not want to dig too deep into this topic anyway this is what I expected and this is the frame.

You can see a tiny reflection of the strobes together with a mask falling on the left hand side… In order to test my theory I run this through false colour on my field monitor, at first glance it looks well lit and this is the false colour.

As you can see the strobes drop below 50 at the green colour band and therefore the nominal width of those strobes is probably 100 degrees. In the deep corners you see the drop to 20 % 10% and then 0 %.

Time to take some shots

The lens is absolutely pin sharp across the frame, I was shooting at f/5.6 in the 140 mm glass dome.

Performance remains stunning across the zoom range. I also tried few shots at f/4

There is no reef background but looks pretty good to me.

The pool gives a strong blue cast so the shots are white balanced.

If you want details of the rig and lens mount are in a previous post

https://interceptor121.com/2019/11/02/fisheye-zoom-for-micro-four-thirds/