I attached two photos. The "fox in the road" file is the jpg file out-of-camera, other than the added text, so you can see how small the fox is, when using a 593mm (35mm equivalent) lens. The "fox portrait" file is a tightly cropped version of the "fox in the road" file, with some tone-mapping and sharpening of the eyes and whiskers. This shows how much digital zooming (about 10x) was done to get the portrait image from the telephoto image. I used my Canon 7D Mark II camera with my Canon EF 100-400mm f/4.5-5.6L IS II USM lens, hand-held. Wonderful camera and lens.
This is a link to my Canon camera on my affiliate's website: http://tinyurl.com/ofo9wqc.
This is a link to my Canon 100-400 lens on my affiliate's website: http://tinyurl.com/o3m6h6w