| **So far, our photo has progressed quite a bit in quality in comparison to the original. However, one aspect is lacking to give the scene a tad more realism: colors. These were lost during the initial photography, when the black-and-white negative was exposed. In a broad sense, the chemicals spread over the glass plate were sensitive only to the general light intensity falling on them. Information was lost concerning the exact wavelengths. In more recent color photographic film, several layers of sensitive chemicals inter-spaced with filters allow retaining information on separate colors on, at least, three different wavelengths. Thus, a (rather good) approximation of the scene’s original colors may be recomposed after processing, making positive copies and development. In our case, however, this color is completely lost to us. In digital terms, what we now see as a level of gray coded 200 on a range of 0 (black) to 255 (white) shows up as a light gray. It is possible that the original color in the scene was a light gray, with red, green and blue values of 200, 200 and 200 and with average intensity 200. But the original color could very well have been 250, 200 and 150, a light salmon color due to the presence of more red and less blue. It could also have been 150, 200 and 250, a light pastel blue, or any other variation of primary colors giving the same average intensity of 200.** | **So far, our photo has progressed quite a bit in quality in comparison to the original. However, one aspect is lacking to give the scene a tad more realism: colors. These were lost during the initial photography, when the black-and-white negative was exposed. In a broad sense, the chemicals spread over the glass plate were sensitive only to the general light intensity falling on them. Information was lost concerning the exact wavelengths. In more recent color photographic film, several layers of sensitive chemicals inter-spaced with filters allow retaining information on separate colors on, at least, three different wavelengths. Thus, a (rather good) approximation of the scene’s original colors may be recomposed after processing, making positive copies and development. In our case, however, this color is completely lost to us. In digital terms, what we now see as a level of gray coded 200 on a range of 0 (black) to 255 (white) shows up as a light gray. It is possible that the original color in the scene was a light gray, with red, green and blue values of 200, 200 and 200 and with average intensity 200. But the original color could very well have been 250, 200 and 150, a light salmon color due to the presence of more red and less blue. It could also have been 150, 200 and 250, a light pastel blue, or any other variation of primary colors giving the same average intensity of 200.** |
