Is the true appearance that always feels the photograph cannot pat him? How is the photograph patted mix in the mirror oneself not quite is resembling? In the photograph do oneself always compare true person fat be? Is this kind of illusion? Your feeling does not have a fault. In camera it is true that you look fatter than true person. But, if the facial decrescent in camera, nose is greatened inevitably by camera. Not clear? Will see a picture first. Cameraman Jim Zub was used film to the different camera lens of 200mm from 20mm person face, let you experience, what calls a face small nose big, facial big nose does not have the contradiction of solution smally. Good, below the camera lens of short focal distance, facial small nose of everybody is big; Below the camera lens of long focal distance, everybody facial big nose is small, do not have illness. This is the scale of the face of camera lens servent of different focal length. Which piece do you prefer? What principle is so nose greatens? Actually, film in close quarters when person face, the scale of nose is met lack fidelity. This is just like the word that you look at from car rearview mirror, the car wants than the object from the back it seems that mostly is a truth. The investigator of university and Stanford university passes Luogesi this year maths builds a model to discover, if your distance in 30 centimeters or so is patted oneself, so nose falls to be able to be compared it seems that in camera lens actual big 30% . But if be in 1.5 meters of right-and-left places,film, it is normal that the scale of nose can be compared. To camera lens, focal distance is longer, the perspective is narrower, vice versa, the camera lens that grows focal length so needs cameraman to stand further to pat, and the camera lens of short focal distance is illuminated comfortable in step is big, because this is big,nose avoided very hard. Actually, the element that lets a person look fat in the photograph still has a lot of, for instance the focal length of camera lens can make of the person facial become compressed, the face that lets you greatens at a draught. Additional, let your face greaten it seems that those who become fat still have an effect, it is called barrel distortion -- this effect can say is very figure, it is linear obviously, arrived below camera lens become curved however, while still alive turned the person into fat person.