Neutral Density Variable Filter K&F 46mm KF X Fader ND2–ND400 (adjustable)

The Neutral Density Variable Filter K&F 46mm KF X Fader ND2–ND400 is an adjustable screw-in ND filter designed for lenses with a 46mm filter thread. It provides a continuous density range from approximately 1 stop (ND2) to about 8.6 stops (ND400), allowing precise control of the amount of light reaching the image sensor. This filter is intended to enable longer shutter speeds, wider apertures in bright conditions, and controlled motion blur or shallow depth-of-field effects during daytime shooting. Constructed to be compact and easy to attach, it integrates with compatible lenses to expand creative exposure options for photography and videography.

Advantages

The variable ND design replaces the need to carry multiple fixed-density filters by offering a smooth, continuous adjustment across a wide attenuation range. It enables photographers and videographers to reduce exposure without changing aperture or ISO, supporting greater creative control over motion rendition and depth of field. The screw-in 46mm mount provides a secure fit on lenses that accept 46mm filters, maintaining optical alignment and minimizing vignetting on lenses with standard wide-to-tele focal lengths. The filter’s compact profile preserves working distance and is suitable for on-location use and travel setups.

Suitable for

• Landscape photography requiring long exposures to blur water and clouds
• Portrait or product work where wider apertures are needed in bright light
• Video capture that requires consistent exposure control and motion blur
• Street and travel photography where a compact, adjustable light control is useful

Key specifications

• Filter type: Variable neutral density (continuously adjustable)
• Density range: ND2 to ND400 (approximately 1 to 8.6 stops of light reduction)
• Thread size: 46mm screw-in
• Mount style: Front filter thread compatible with lenses accepting 46mm filters
• Construction: slim profile designed to reduce vignetting on standard lenses

How to use

Attach the filter by screwing it onto a lens with a 46mm thread until it is secure but not overtightened. Rotate the front element to adjust the density continuously from ND2 to ND400 while observing exposure changes in the viewfinder or on the camera display. For photography, select a shutter speed and aperture appropriate for the creative effect you want (for example, longer shutter speeds for smooth water). For video, adjust the filter to maintain desired exposure while keeping shutter speed consistent with frame rate. When finished, unscrew the filter and store it in a protective case to avoid scratches.

Usage recommendations

To avoid cross-polarization or uneven darkening, set the filter to the desired density and make fine adjustments while monitoring the image. Use the lower end of the range for subtle exposure control and the higher end for strong motion blur; be mindful that extreme settings can introduce color shifts or require additional post-processing correction. Clean filter surfaces gently with a microfiber cloth and appropriate cleaning solution to maintain image quality.