BS ISO 9848-2004 摄影.源文件缩微胶片.ISO感光速度和ISO平均梯度的测定

标准号：BS ISO 9848-2004
中文标准名称：摄影.源文件缩微胶片.ISO感光速度和ISO平均梯度的测定
英文标准名称：Photography - Source document microfilms - Determination of ISO speed and ISO average gradient
标准类型：G81
发布日期：2004/4/5 12:00:00
实施日期：2004/4/5 12:00:00
中国标准分类号：G81
国际标准分类号：37.040.20;37.080
适用范围：This International Standard specifies a method for determining the ISO speed and ISO average gradient of black-and-white camera negative photographic films used for first generation microfilming of source documents at exposure times typically found with tungsten sources. These source documents include any handwritten or printed alphanumeric and line documents such as books, periodicals, business correspondence, and engineering drawings. The value-rating system described in this International Standard is only useful to the consumer if his exposure illumination is from an incandescent tungsten source as described in 5.3.3. It is not intended to include pictorial or continuous tone reproduction, computer output microfilm (COM), reversal processed or direct positive films or other films exposed by non-tungsten sources such as laser or cathode ray tube. The ISO speed and ISO average gradient values obtained by applying this International Standard are intended for practical use in comparing film/process combinations and for computing exposures.