Citiwide MC Variable NDX (ND2-400) Filter

Easy to Use
Turn the outer ring to dial in amount of neutral density desired
Easy Framing / Easy Focus
With a tripod mounted camera, use the brightest setting for framing and focus and then increase the density to your desired level by using the outer ring
Eliminates Vignetting
By using this single filter, you avoid stacking multiple ND filters that can cause vignetting (the darkening of the corners of the image)
For Longer Exposures
Without changing the aperture, the NDX filter allows the freedom to change the shutter speed according to the effect desired. For example, without adjusting the aperture, the same 1/60 scene can be taken using the Variable NDX filter with shutter speeds from 1/20 to 16 seconds with just a twist of the outer ring. The problem of diffraction is eliminated by being able to work with a slow shutter speed
For Wider Apertures
With the Variable NDX filter, the shutter speed remains constant for a wide aperture easily creating a blurred background effect
Excellent for Landscape Photography
The ability to change different shutter speeds permits you to create unusual effects outdoors
Flex Light Control for Digital SLR HD Video
For HD video-enabled cameras, use the Variable NDX filter to easily adjust light control and for manual fade-in/fade out effects
Neutral Density Filters Have Four Main Uses
To enable slow shutter speeds to be used, especially with high speed films, to record movement in subjects such as waterfalls, clouds, or cars
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 (above ISO 400) and allow it to be used outdoors in bright situation
To allow cine and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which could cause overexposure