Sensitometry

…To determine the sensitivity of a photographic material, the material is exposed in a sensitometer in a specified manner, developed in a specified manner, and the sensitivity is calculated from the relationship between the photographic density of the image obtained and the amount of exposure. Measuring the sensitivity of a photographic material is called sensitometry. In the case of ISO speed indications for negative film for general photography, the speed S is calculated from the exposure H _m (unit: lx･s) at the sensitivity measurement standard point using the formula S = 0.8/ H _m to obtain the arithmetic speed value. …

*Some of the terminology that mentions "sensitometry" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…写真感度材料の感度を求めるには，感光材料を感光計で規定の方法で露光し，規定の現像方法で現像し，得た画像の写真濃度と露光量との関係から感度を算出する。感光材料の感度測定をセンシトメトリーsensitometryという。一般撮影用ネガフィルムのISOスピード表示の場合，スピードSは，感度測定規準点の露光量H_m(単位lx･s)から，S＝0.8/H_mの式で求めて算術的スピード値とする。…

※「sensitometry」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報