Neutral Density Variable Filter K&F KF01.1443 37mm ND8–ND128 adjustable (gray)

The Neutral Density Variable Filter K&F KF01.1443 37mm ND8–ND128 adjustable (gray) is a screw-on optical accessory designed for lenses with a 37 mm filter thread. It provides continuously variable light attenuation between approximately 3 and 7 stops (ND8 to ND128), allowing photographers and videographers to extend exposure times or open apertures in bright conditions. The gray (neutral) tint preserves color balance while reducing incoming light, making it suitable for controlled motion blur, shallow depth of field in daylight, and smoother video exposure control.

Advantages

The filter offers a wide adjustment range in a compact 37 mm form factor, enabling flexible control over exposure without changing individual fixed-density filters. Its neutral-density design minimizes color cast so that white balance adjustments remain predictable. The screw-in mounting ensures a secure fit on compatible lenses and a low-profile build helps avoid vignetting on small-format optics. Continuous rotation allows fine incremental changes for precise exposure and creative effects.

Suitable for

• Landscape photography requiring long exposures to soften water and cloud motion
• Portraits and outdoor shallow-depth-of-field shots in bright light
• Videography where stable shutter control and smooth exposure transitions are needed
• Architectural and street scenes that benefit from motion blur or reduced highlights

Key specifications

• Filter type: Variable neutral density (ND) — adjustable from ND8 to ND128
• Thread size: 37 mm screw-in
• Color: Gray (neutral density to preserve color balance)
• Light reduction range: approximately 3 to 7 stops
• Mounting: Screw-on with continuous rotation for variable attenuation

How to use

Screw the K&F variable ND filter onto the front thread of a compatible 37 mm lens until it is snug but not overtightened. Set your camera exposure settings (shutter speed, aperture, ISO) for the desired base exposure, then rotate the outer ring of the filter to increase or decrease light attenuation until the target exposure or creative effect is achieved. For long-exposure landscape shots, use a tripod and live view or histogram to confirm correct exposure. When shooting video, rotate slowly to avoid abrupt changes in brightness. Remove the filter when it is no longer required to restore full light transmission.

Usage recommendations

To reduce risk of color shifts or cross-polarization effects, check results at multiple settings and adjust white balance as needed. Use a lens hood to minimize stray light on the filter surface and carry the filter in a protective case to avoid scratches. For extreme attenuation settings, compose and focus before attaching the filter or use live view/focus assist to maintain sharpness.