Well, the lens I used here, a Canon 70-200 f/4L, with a Canon 500D closeup lens on it would only focus in as close as 22" so I tried Maximiliano's test at 22" and 60". I hope that is close enough.
Anway, Maximiliano asked if those two images would look the same. I didn't expect that they would. My whole premise is that perspective is determined by camera to subject distance, not by lens.
So, let's take a look at the results...
|Camera 22" from the subject's eye|
|Camera 60" from the subject's eye|
|Click to enlarge|
Can you see the difference? The image taken at 22 inches has a nice gentle curvature of the cheek as it wraps around from the nose to the ear. The one at 60" is flatter.
This being the internet and all that, I know someone is going to suggest that maybe it is the optics of a zoom lens, even if both images were taken at 100mm. Or someone may suggest that adding the 500D close up filter to allow the 70-200 to focus so close are affecting things. I can assure you they are not.
But in the sense of full testing, I pulled out an old Tamron 90mm macro lens that could focus at 18 inches and repeated the tests. I think you will see the same results...
|Camera at 18" from subject's eye|
|Camera at 60" from subject's eye|
|Click to enlarge|
Please, don't just take my word for it. What I really want you to do is to go out and try these things yourself. Just because a book says it is so, or some photographer on the net says it is so doesn't mean they are always correct.
So, go out and take some photos of the same person or mannequin (they tend to hold still longer for a better comparison) and see what happens as you move around them and move closer and further away. And then try a higher or lower camera angle than you usually use. Experiment. These don't have to be images that you show to anyone else. They are references for yourself. Write your own photography book using the tests you run yourself.
Thank you Maximiliano for asking your question. I love questions. Please post yours in the comments if you have some.