ISO 10505:2009描述了一种测定照相胶片固有均方根粒度（rms？粒度）的方法。固有rms粒度是指仅由显影图像形成中心在照相乳剂中的分布产生的那些密度波动。 涂覆在透射载体上的连续色调单色(银吸收物质)和彩色(染料吸收物质)材料可以通过ISO 10505:2009中描述的程序来测量。ISO 10505:2009适用于观察放大倍数在5倍至12倍之间的成像系统（参见附录A）。 ISO 10505:2009未涵盖以下粒度测量，尽管它们在摄影上很重要: 反光材料（相纸）； 在载体的两侧涂覆有乳液的材料(例如一些X射线胶片)； 噪声功率谱（维纳谱）的估计。

ISO 10505:2009 describes a method for determining the intrinsic root mean square granularity (rms？granularity) of photographic films. Intrinsic rms-granularity refers to those density fluctuations produced solely by the distribution of developed image forming centres in the photographic emulsion. Continuous-tone monochrome (silver absorbing species) and colour (dye absorbing species) materials coated on a transmitting support can be measured by the procedures described in ISO 10505:2009. ISO 10505:2009 is intended for imaging systems with viewing magnifications between 5x and 12x (see Annex A). The following kinds of granularity measurements are not covered by ISO 10505:2009, even though they are photographically important:

• reflecting materials (photographic papers);
• materials having emulsion coated on both sides of the support (e.g. some X-ray films);
• the estimation of the noise power spectrum (Wiener spectrum).