寫眞의 被寫體와 背景의 露出測定 比較 = An Exposure Measuring Comparison of Photo Subject with Contrast Background

다국어 초록 (Multilingual Abstract)

The relation between photo Subject and background is a full Compromise condition in exposure determination. It is necessary to consider the circumstances of photo subjects and backgrounds with variations of brightness, darkness, texture of surface and color for good result. This study was planned to analyze the results of pictures by a series of work, exposuring, developing and printing. A doll as a photo subject and four different backgrounds were set under the same lighting of a flood -lamp at a fixed distance for following comparison of influenced subject by contrast backgrounds. White Kent paper was the most bright background and black textile was extreme dark background. The medium grey textile and reflecting surface aluminium foil were used too. By measuring with light meter, the contrasts of brightness and darkness were checked up on the backgrounds. The white background was 16 times as bright a s black one, 4 times as bright as grey one and twice as bright as aluminium foil. The brightness of grey back was intermediate between whtie one and black one the former the most bright one and the latter the most dark one. The subject in white background was twice as bright as that in the other backgrounds because brightness of subject was influenced by brilliant background. In reflecting background, diffused reflection influenced upon subject partially. Under-exposed situation could result from extreme bright background or subject when they are exposed by average light metering without modification. On the other hand, over -exposed circumstances could come out of extreme dark background or subject by direct applications of measured light value without modification. It was difficult to measure the light under the condition of reflecting background, because diffused reflection interferes with light metering. We could check up the circumstances of over--exposure and under-exposure partially on the photographed subject caused by diffused reflection. The grey-tone background offers proper condition for subject on the whole. Following conaiderations are available for good result of photos
A, Exposure of extreme bright or white subject and background has to be increased to prevent under-exposure.
B, Exposure of extreme dark or black subject and background has to be reduced to prevent over -exposure.
C, Partial light metering is superior to average light metering for correct exposure on the average.
D, Background ought to be regarded as a photo subject to determine correct exposure.