B+W 62mm MASTER Neutral Density 810M (>1%, 10 stop) Filter, darkens the subject area by ten f-stops without changing its color. Ideal for Landscape Photography, the 810M is finely polished glass and lasts longer than easily scratchable plastic substrates. It is used when no suitable aperture can be selected in bright light or when a specific, short DOF is required. Running water virtually transforms into mist. People walking on streets become blurred and indistinct or even invisible. In some cases this involves extremely long exposures of up to one minute. A stable tripod is essential.