Hello James,

I'm new using the Canon 90D and I use with my 100-400L II and I really like the results, sharpen photos with a great contrast.

But during the past few days I have used my 100-400 II with 2x extender and some photos show some parts out of focus. And I tried using only my Sigma 50-500 lens and I see the same results, out of focus photos with a few shadows around the aircraft.

I'm starting to believe that it can be something wrong with the compability of Canon 90D with the some lenses....