Neutral Density Variable Filter K&F SB7475 55mm ND3–ND1000 adjustable

The K&F SB7475 55mm Variable Neutral Density (ND) filter ND3–ND1000 reduces the amount of light entering the lens to allow controlled exposure in bright conditions. This 55 mm screw-in filter provides a continuously adjustable density range from approximately ND3 to ND1000, enabling longer shutter speeds and wider apertures without overexposure. It is designed for use with lenses that have a 55 mm filter thread and helps achieve motion blur, smooth water effects, and shallower depth of field when ambient light would otherwise prevent such settings.

Advantages

The filter offers smooth and stepless density adjustment across a broad range, letting photographers fine-tune exposure without swapping filters. Its screw-in 55 mm mount ensures secure attachment and compatibility with lenses that accept 55 mm filters. The neutral density effect preserves color balance while reducing light intensity, supporting creative control over shutter speed and aperture. Constructed to minimize vignetting on standard focal lengths when used correctly, it is compact and easy to carry in a camera bag.

Suitable for

• Landscape photography requiring long exposures to smooth water and cloud movement
• Long-exposure urban and night scenes to capture light trails and motion effects
• Portraits and outdoor shoots where wider apertures are needed in bright light
• Time-lapse sequences that need consistent exposure control in changing light

Key specifications

• Filter type: Variable neutral density (ND)
• Adjustable density range: approximately ND3 to ND1000
• Thread diameter: 55 mm (screw-in)
• Optical characteristic: neutral density with color-neutral attenuation
• Construction: multi-element glass with metal filter ring (compact design)

How to use

Screw the filter onto the front of a lens with a 55 mm filter thread until it is secure but not overtightened. Rotate the front element to change the density and observe the exposure meter or histogram to reach the desired shutter speed or aperture. For very long exposures, use a tripod and remote release or camera timer to avoid camera shake. When using wide-angle lenses, check for vignetting at stronger density settings and reduce density or crop if necessary. Store the filter in its protective case when not in use to prevent scratches and dust.

Usage recommendations

For best results, set white balance manually or use a gray card reference to maintain neutral colors. When photographing at extreme density settings, verify the scene through a test exposure—variable ND filters can produce cross-polarization artifacts on some wide-angle setups, so adjust rotation or reduce density if banding appears.