The relative sizes depend on the relative distance from the camera. Say you have two persons, one standing one meter in front of the other, and the photographer

The relative sizes depend on the relative distance from the camera. Say you have two persons, one standing one meter in front of the other, and the photographer standing one meter in front of the frontmost person, shooting with a wide-angle lens so that the nearest person fills the frame. The far person is then twice as far away as the near person (2m vs. 1m), and will appear half the size of the near person (assuming they're the same size in reality!). The photographer then moves 50 meters away, and shoots with a (really!) long telephoto lens, so that the nearest person still fills the frame. The near person is now 50 meters away and the far person is 51 meters away, and will appear 50/51 of the near persons's size. (This would still happen if the photographer kept the wide-angle lens, but then a lot more of the surroundings would have been included in the frame, making it obvious that the persons were far away. Whether tele/wide-angle "affects perspective" is a favourite topic of endless debate on photo-related Internet forums. The answer hinges on which parameters you maintain constant, and which ones you allow to vary.)