By greatly extending exposure times the Big Stopper blurs anything that is moving in your image, for example clouds, waterfalls, rivers, and the sea.
The filter can also be used on cityscapes to blur people or on roads and motorways to blur traffic.
The Little Stopper can give increased flexibility with exposure lengths in the lower light at the start and end of the day. This often means that detail and texture can be retained in areas of movement such as the sky and water, while still conveying a sense of time passing.
Formatt Hitech 100mm Neutral Density Grad.Neutral density (or ND) filters produce a grey neutral tone and are used in photography to reduce light, enabling more control over exposure and depth of field .