1. A photography apparatus comprising: imaging means for obtaining an image of a subject by photography thereof; an auxiliary light source for emitting auxiliary light at the time of the photography; parameter acquisition means for obtaining a weighting parameter for a statistical characteristic quantity representing a lighting condition for a predetermined structure in an input through image by fitting a model representing the structure to the structure in the input through image, the model having been obtained by carrying out predetermined statistical processing on a plurality of images representing the predetermined structure in different lighting conditions, and the model representing the structure by one or more statistical characteristic quantities including the statistical characteristic quantity representing the lighting condition and by weighting parameter or parameters for weighting the statistical characteristic quantity or quantities according to an individual characteristic of the structure; and auxiliary light source control means for controlling the auxiliary light source so as to cause a condition of lighting for the subject to become appropriate according to a value of the weighting parameter having been obtained.