This 150 x 150mm SW150 Big Stopper ND Filter from LEE Filters is an ND filter with a 1,000x filter factor that provides a 10 stop exposure reduction. Its 3.0 density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than normally required. By slowing your exposure time or increasing your aperture, you are able to control depth of field and convey movement more easily. Neutral density filters do not affect the coloration of the image and are ideal for pairing with other filters.
This SW150 Big Stopper neutral density filter is constructed from optical glass for clarity as well as color fidelity and features a built-in gasket. This gasket works with a compatible LEE Filters SW150-series filter holder with an integrated or add-on Lightshield to help form a seal that is intended to prevent stray light, which could have unwanted effects on exposure, from coming in between the filter and the lens behind it. For efficient use in the field, an exposure guide is included that shows the amount of exposure reduction the SW150 Big Stopper Neutral Density 3.0 Filter provides, corresponding to a range of shutter speed settings from 1/1,000th of a second to 2 seconds before the filter is applied.