Long Exposure Filters
Long exposure filters are used to extend the length of an exposure (shutter speed). Extending the shutter speed allows anything that is moving in your image to become blurred or ghost like. Subjects such as clouds, waterfalls, rivers and the sea work particularly well. However the effect is not limited to landscapes, the filter can also be used on cityscapes to blur people or roads and motorways to blur traffic.
No Filter Taken with a long exposure filter
Calculating the correct exposure for a long exposure filter is very simple. Take a meter reading as normal WITHOUT the filter in place, and decide on the aperture required for the shot. If using a 10 stop long exposure filter you need to add 10 stops of exposure to the shutter speed that matches your chosen aperture (double the exposure length 10 times). For example a metered exposure of a 30th of a second at f11 would need to be increased by 10 stops making a new exposure time of 32 seconds.
A handy card is supplied with a LEE long exposure filter to help you calculate your exposure times.
No Filter Taken with a long exposure filter
Long exposure filters can be used in conjunction with other filters such as Neutral Density Graduated Filters. Other filters should be set up and positioned in the filter holder as normal before using the filter.
