« on: Today at 06:45:46 PM »
I am going to eat some of my words. Yesterday, at the end of some miserable attempts to photograph birds at a reserve, I stopped off at the visitor centre where you could see a Swarovski target that had been placed for an exhibition and had been left behind, a 100 or so metres away. Here is a shot of the target with 420mm on the 5DIII, to get a feel for the scene. Next, is an unsharpened crop from RAW of the target with the 100-400mm on the 7DII at 400mm f/5.6 (the crop is close to 400 px wide at 100%). Below that is at f/8 and 560mm (about 560 px wide). At the bottom it's at 800mm f/11 using live view (close to 800 px wide). On going from 400mm to 500mm, there is a little improvement in resolution. But, on going to 800mm, it becomes much clearer and you can even read the numbers in the circle. I was so flabbergasted on getting home, that I checked my focus just in case live view was better than AF - it wasn't. It is just that you need to get to 800mm to resolve the fine details, and below that they are merged (below the Nyqvist limit).
So, the 100-400mm II takes the 2xTCIII very well, and the 7DII focusses really well in live view at f/11. I can't wait to photo the moon with the 7DII/800mm, and I am drooling at the thought of a 400 DO II with a 2xTC!
The first relatively clear night. It was still hazy, but I tried out the 7DII + 2xTCIII + 100-400 II. I processed in DxO, PRIME with clearview to help remove the haze. The performance was creditable, and compared not too badly with a shot with the 300mm/2.8 + 2xTC (below).