I was shooting with 7D Mark II using a 500 plus 1.4x extender the first time.
I had two target areas (put down some food on the snow).
One was about 20 feet away, the other was about 80-85 feet away.
The closer ones came out beautifully sharp.
The ones at longer distance lacked details, implying out of focus situation
but they might not have been at all.
Thanks for looking.
Canon 7D Mark II
Canon 500 f4.0 L IS Mark II +1.4x III.
ISO 320
1/3200s
f 7.1