Grains are the exposed and developed silver halide crystals that have transformed into black metallic silver, forming the visible image on photographic film or paper. Their size and distribution determine the texture and level of detail in the final image.
Finer grains produce sharper, more detailed photographs, while coarser grains can create a distinctive, textured appearance. Understanding the role of grains is essential for photographers working with film, as it affects choices in film type, development, and printing to achieve the desired visual effect.