Wow these are some lenses, thanks first of all to lensrentals.com, they are just awesome. I needed these lense for shooting a sailing regatta that was probably 1km away, it’s tough to get shots like this, but at least the boats are moving slow, so I could use ultra high resolution bodies (the Canon 5DS R and the Sony A7R II).
The really tough choice was picking lenses, I have always loved the Nikon 200 F/2 as it was just so clear and wonderful two years ago and for some reason I didn’t have very fond memories of the Canon 300mm F/2.8 II. The main reason is that you lose quite a bit of image quality with a 2x teleconverter I think,
This time I wanted to see if the Metabones E to EF adapter was a choice, so off to Canon I went. Wow what an experience. First of all, the Canon 5DS R really worked well with the 600MM F/4L and 1.4x extender mainly because conditions were super bright and of course this camera is very fast. I was able to shoot at ISO 200 and even wide open at f/5.6 this lense was tack sharp. That’s quite a bit of reach at 840MM (with full frame 35mm, that’s a 24x zoom). This is quite a lense as DxO says it achieves 37MP with the 50MP sensor on the 5DS R.
And with so many pixels, even with a crop by another 2-4x (so that’s an effective 48-96x zoom), the photos were very usable. The autofocus by the way worked very well, with AI Servo on the Canon or the equivalent on the Sony, object tracking worked really well.
Finally, we also used the Metabones with a Sony A7R II, this was a little more difficult because the Metabones seemed to have trouble connecting problem to the  A7R. In fact, lens rentals doesn’t recommend it for professional shoots and I can see why. When it was working properly though (required some jiggle of the the adapter and rebooting the adapter by removing the camera), the image quality was excellent. Theoretically the 42MP vs 50MP should have made a difference but I couldn’t see it.
One disappointment was that I never quite got the video mode of the A7R to work, it is supposed to automatically stabilize through the metabones, but in looking at the video, I couldn’t quite get it to work.
Finally, if you are going to use lenses like this, the Wembley Sidewinder is a must have, it converts your tripod and makes it easy to move a big heavy lenses set like this. And make sure you bring a beefy tripod and put a weight on it, with this kind of zoom, even someone walking causes vibration. I had both image stabilization turned on and also shot at 1/800 and this seemed to work.

I’m Rich & Co.

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