Zone 0: Total black in print. No useful density in the negative other than filmbase-plus-fog.
Zone I: Effective threshold. First step above complete black in print, with slight tonality, but no texture.
Zone II: First suggestion of texture. Deep tonalities, representing the darkest part of the image in which some slight detail is required.
Zone III: Average dark materials and low values showing adequate texture.
Zone IV: Average dark foliage, dark stone, or landscape shadow. Normal shadow value for Caucasian skin portraits in sunlight.
Zone V: Middle gray (18% reflectance). Clear north sky as rendered by panchromatic film, dark skin, gray stone, average weathered wood.
Zone VI: Average Caucasian skin value in sunlight, diffuse skylight or artificial light. Light stone, shadows on snow in sunlit landscapes.
Zone VII: Very light skin, light gray objects, average snow with acute side lighting
Zone VIII: Whites with texture and delicate values; textured snow; highlights on Caucasian skin
Zone IX: White without texture approaching pure white, thus comparable to Zone I in its slight tonality without true texture. Snow in flat sunlight.
Zone X: Pure white of the printing paper base; specular glare or light sources in the picture area.