4K 디지털카메라의 다이나믹레인지와 정색성 연구 - 사진촬영기능과 영상촬영기능의 비교-

Abstract

This paper seeks to study whether a captured 4K image can realize a dynamic range as wide as a RAW file of a photograph and measure the image’s color intensity. In case of photograph, a Q-14 chart was shot at normal exposure, set at RAW. The shooting was conducted through Adobe RAW from +5 stop to –5 stop with an exposure difference of 1/3 of a stop. Then the images were converted into TIFF. In case of video, a Q-14 chart was shot by changing exposures similar to RAW through adjusting shutter speed. The dynamic range was measured through stepchat of imatest. The standard mode (STD) in the photo camera setting showed a range of 5+1/3 stop. S-Log2 in the video setting showed a range of 6 stop while RAW showed a range of 6+2/3 stop. When shot at normal exposure, the highlight area of S-Log2 was 1+2/3 stop higher. However, compared to RAW and the camera setting of STD, its photographic expression of the shadow area was 2+2/3 stop short. In case of standard mode (STD), the ΔE*ab value was shown somewhere around 10. However, in case of S-Log2, the ΔE*ab value was around 28 so the color was inaccurate compared to the camera setting. Yet, by adjusting the inner video settings, the ΔE*ab value recorded somewhere between 12 and 17, confirming the possibility of realizing correct colors at the similar level with a photograph. Therefore, the study will be a useful reference in applying image features to photography for those in the field of photography.