By Suwat PUENPA and Onsucha UPAKIT

Year 2013

Abstract

Photography now is not a difficult job like in the past. However, the good photography requires both knowledge in science and art. Most critical part in photography is calculation of the exposure light. For digital single-lens reflex camera (DSLR), light sensitivity can be variously set. That light sensitivity strongly has an influence on color image quality. This research is then aim to examine the effect of light sensitivity on color image. A color checker composed of 24 color chips was taken by a DSLR setting its color temperature at 5500 K. The images were specifically taken under natural light or sunlight when the color temperature of light is equal to 5500 K. The light sensitivity levels were set at ISO 100, 200, 400, 800, 1600, 3200 and 6400. Shutter speed was adjusted to offset the amount of light in order to obtain normal exposure images. The taken images were output on two media. The first one, the taken images were output on a monitor. The second one, we developed the taken images with C-41 process and printed out on glossy paper. CIELAB of each color chips were measured by a spectrophotometer and compared between each image taken with different ISO. Our results exhibited that most color in the taken image were slightly affected by ISO sensitivity. There is no large difference of each color in each taken image except for red and blue color. At ISO 400 and 800, CIELAB of red and blue were significantly different from reference values.

Download : Effect of sensitivity levels of digital single-lens reflex camera on color image