In this exercise plan to make exactly the same framing on a fence with different focal lengths. With a zoom lens, use at least three; at either end of the zoom scale and in the middle.
Examine the results. The proportions will be different, and in general, the longer the focal length, the more attractive the face will appear. Note your own judgement of the differences according to how attractive or acceptable you think the results look.
I was using a 28-200mm zoom for this, its not my usual lens so I was interested to see how it was for portraits, all of the images within these exercises were undertaken using it through the different focal lengths so by the time I came to this exercise, I wanted to try something different and see how the same pose would look through three different lengths, the first one the lens is at wide angle to take in the background and full length portrait, the second is towards the middle of the zoom and gives a really nice upper torso portrait with the background starting to get a bit more blurred and not too distracting. The final image with the lens on its higher zoom gives a better portrait, the background is blurred and non obtrusive, the face is prominent and the eye is drawn to this first. The face is a good shape without obvious signs of any distortion, this is the advantage of a longer lens over a wide angle one which can alter the shape of the face.
32mm 110mm 200mm