Addendum: Just a note. I have never fully grasped the science, but there appears to be some evidence that the effects of perspective from closer distances are somewhat less pronounced in a print from large format than from, say, 35mm, a property owing to the degree of enlargement and typical viewing distance to the print. In many cases, however, it is hard for the viewer to immediately perceive a "pronounced" close perspective (within limits) without knowing the subject; immediately, that is, because scrutiny might indicate proportions that suggest the closer distance. However, a face can be slimmed, from some angles, from closer up as compared with a greater distance, and broadened a bit from further away. In any case, the totality of the portrait in and what it conveys is what counts, and in this, we certainly have a great deal of freedom -- and a great deal of challenge!