The SW150 Super Stopper is a 150x150mm square glass neutral density filter which reduces light transmission by 15 stops. This enables long exposure times to be used in bright daylight so that anything which is moving in your image becomes blurred or ghost-like. Subjects such as clouds, waterfalls, rivers and the sea work particularly well. Traffic and people in cityscapes will disappear from the image. Supplied with foam lined protective tin.