[The influence of camera-to-object distance and focal length on the representation of faces].
When one thinks of the so-called barrel or wide-angle distortion, grotesquely warped faces may come to mind. For less extreme cases with primarily inconspicuous facial proportions, the question, however, still arises whether there may be a resulting impact on the identification of faces. In the first experiment, 3 test persons were photographed at a fixed camera-to-object distance of 2 m. In the second experiment, 18 test persons were each photographed at a distance of 0.5 m and 2.0 m. For both experiments photographs were taken from a fixed angle of view in alignment with the Frankfurt Plane. An isolated effect of the focal length on facial proportions could not be demonstrated. On the other hand, changes in the camera-to-object distance clearly influenced facial proportions and shape. A standardized camera-to-object distance for passport photos, as well as reconstruction of the camera-to-object distance from crime scene photos and the use of this same distance in taking photographs for comparison of suspects are called for. A proposal to refer to wide-angle distortion as the nearness effect is put forward.
Verhoff
Marcel A
MA
Institut für Rechtsmedizin am Universitätsklinikum Giessen.
Witzel
Carsten
C
Ramsthaler
Frank
F
Kreutz
Kerstin
K
D000328:Adult; D003418:Criminology; D005145:Face; D005260:Female; D006801:Humans; D008297:Male; D055095:Optics and Photonics; D010781:Photography / Q000379:methods*