The ND2-400 Filter is a variable neutral density filter with a rotating front lens. It has exposure correction between +1 and +8 stop values possible, and is used to reduce light that is too bright.
The Vario ND2-400 has various applications, for instance it can allow the photographer to use large apertures while taking pictures outside = backround gets hazy. In the case of exposure times longer than 1/30 seconds, water "flows", if they are shorter, it freezes to ice.
- They have Four main uses:
- To enable slow shutter speeds to be used, especially with fast films, to record movement in subjects such as waterfalls, clouds, cars, seas etc.
- To decrease depth of field by allowing wider apertures to be used, which helps separate subjects from their background.
- To decrease the effective ISO of high speed film (ie: above ISO400) and allow it to be used outdoors in blight situations.
- To allow cine and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which would normally cause over-exposure.
Note: To avoid vignetting, this filter has a superstructure of the front lens - the diameter of the front lens is larger than that of the rear lens. Please note that a lens cap with next level of lens filter thread is therefore required. (for example, 49mm NDX filter required 52mm Lens cap)