은염과 디지털 사진의 재현 특성을 고려한 조명비 조절 방법에 관한 연구

Abstract

This research is to compare the reproduction characteristics of silver halide and digital photography according to the lighting ratio and understand the difference between them in order to suggest the right control method of lighting ratio in the digital photography. The lighting ratio means the difference in the quantity of key light and fill light and because it affects on the brightness and contrast of overall photography, it is used as a major technique to express a three-dimensional effect of the subject. Also, the brightness and contrast in the photograph can change the delivered information by the subject and emotional and cognitive system of human, therefore, it becomes a significant technique to express the image. Specially, because the lighting ratio in portrait photography plays significant role in portrait of a person, the research on the lighting ratio has been done steadily so far. Therefore, it can be seen that the lighting ratio theory in silver halide had been established as empirical data or literature. As approaching to the digital photography period, however, many photographers are undergoing confusion in reproduction of the lighting ratio in digital photography. It is because that the expression method with the existing experience and data may not be accurately applicable to the digital photography. In digital photography, it reproduces differently from the film according to the characteristic of digital camera. In the experiment of this research, as the lighting ratio becomes higher, the film showed that the brightness of shadow became darker while the digital camera showed the brightness of shadow are became brighter. Therefore, compared to the film, the contrast of photograph taken by digital camera was lower. In order to make similar reproduction with film when using digital camera, similar lighting ratio with film should be maintained from 1:1 to 1:8, but from 1:16, the quantity of fill light should be reduced by 1/3∼2/3 stop sequentially. Or, in case of photographing with the same lighting ratio with film, it is recommended to reduce the brightness of dark area through retouching. As this may be dependent on the kind of processor or what parameter was used, however, it is suggested to test the characteristic of digital camera just as to understand that of film.