Neutral Density Variable Filter K&F 49mm Fader ND8–ND2000 (model SB6574)

The Neutral Density Variable Filter K&F 49mm Fader ND8–ND2000 (model SB6574) is a screw-on optical filter designed for lenses with a 49mm filter thread. It provides continuous attenuation of incoming light, with an adjustable range from approximately ND8 up to ND2000. This variable ND filter helps control exposure in bright conditions, allowing photographers to use slower shutter speeds or wider apertures without overexposing the image. The compact, metal-frame design fits standard 49mm lenses and is suitable for field and studio use where flexible light reduction is required.

Advantages

The filter offers a wide, continuously variable density range that covers mild to very strong light reduction, enabling precise exposure control. Its screw-in 49mm mount ensures compatibility with lenses that accept 49mm filters and provides a secure attachment. Multi-coated optical elements reduce reflections and maintain color neutrality while lowering the risk of flare. The metal frame provides durability and stable threading for repeated attachment and removal.

Suitable for

• Landscape photography with long exposures to smooth water and cloud motion
• City and architecture shots requiring motion blur at daytime
• Portraits and shallow depth-of-field work in bright light using wide apertures
• Time-lapse sequences and cinematic video where controlled shutter speed is needed

Key specifications

• Filter type: Variable neutral density (continuous ND)
• Density range: approximately ND8 to ND2000
• Mount thread size: 49mm screw-in
• Frame material: metal
• Coatings: multi-coated optical surfaces to reduce reflections and flare
• Primary function: adjustable light attenuation for exposure control

How to use

Screw the filter onto the front of a lens with a 49mm filter thread until it is snug but not overtightened. Rotate the outer ring to adjust the density and preview exposure changes through the viewfinder or live view. For long exposures, select a shutter speed appropriate for the motion effect you want and then fine-tune the filter rotation to reach the correct exposure. When using wide apertures in bright light, increase density until the desired aperture and shutter speed combination is achievable without overexposure. Check for vignetting at wide focal lengths and reduce density or crop if necessary.

Usage recommendations

Avoid stacking multiple dense filters with the variable ND at high attenuation settings to reduce the chance of uneven darkening or cross-polarization effects. When shooting landscapes or long exposures, use a tripod and remote release or self-timer to minimize camera shake. Store the filter in a protective case when not in use and clean the optical surfaces with a microfiber cloth and lens-safe cleaning fluid.