Choosing the right lens for doing a portrait can greatly impact your subject and how they look. Above I shot these photos filling the frame so that the head size was pretty close to the same size in the frame.
I shot all these photos on the Nikon D750 using three lenses: 1) AF-S NIKKOR 14-24mm f/2.8G ED; 2) AF-S NIKKOR 28-300mm f/3.5-5.6G ED VR; & Nikon 85mm ƒ/1.8G.I believe both the wide angle and the extreme telephoto lens do affect how a person’s face appears.
The extremely wide angle makes a person’s nose bigger because it is closer to the camera and the ears are much further. As you go to a longer focal length the distance between the nose and ears compresses.
My favorite lens for portraits with the full frame DSLR is the Nikon 85mm ƒ/1.8G.