標準號：BS ISO 9848-2004
中文標準名稱：攝影.源文件縮微膠片.ISO感光速度和ISO平均梯度的測定
英文標準名稱：Photography - Source document microfilms - Determination of ISO speed and ISO average gradient
標準類型：G81
發布日期：2004/4/5 12:00:00
實施日期：2004/4/5 12:00:00
中國標準分類號：G81
國際標準分類號：37.040.20;37.080
適用范圍：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.