ABSTRACT

A modified digital camera can be used for photographic techniques that utilize not only the visible light spectrum but longwave ultraviolet and near-infrared radiation. Seven techniques were used to document salted paper prints: visible light photography with normal, raking, and specular illumination, UVA-induced visible fluorescence, reflected UVA, reflected near-IR, and visible-induced infrared luminescence. The last four techniques, in particular, can reveal or accentuate subtle differences in materials or condition issues of salted paper prints that may otherwise be hard to discern in visible light. In order to achieve consistency, a standardized workflow was created taking into consideration several important factors, such as light and radiation sources, setup, lens choice, use of filters, and incorporating target references for color rendering, exposure control, and image processing procedures. An exposure sequence is suggested to safeguard the prints and to increase efficiency. Total exposure was monitored to ensure that light and UVA exposure during documentation did not induce detectable change.

摘要

改进的数码相机可用于不仅利用可见光谱而且利用长波紫外线和近红外辐射的照相技术。七种技术被用来记录盐腌的纸印品：具有正常，倾斜和镜面照明的可见光摄影，UVA诱导的可见荧光，反射的UVA，反射的近红外和可见的红外发光。尤其是后四种技术，可以揭示或突显盐纸印刷品的材料或状况问题上的细微差异，否则它们在可见光下很难辨别。为了达到一致性，我们创建了标准化的工作流程，其中考虑了几个重要因素，例如光源和辐射源，设置，镜头选择，滤镜的使用，并结合了用于色彩渲染，曝光控制和图像处理过程的目标参考。建议采用曝光顺序以保护印刷品并提高效率。监测总暴露量以确保记录期间暴露于光和UVA不会引起可检测的变化。