Hybrid Camera Filter K&F Concept 2-in-1 CPL + Solid Neutral Density ND2–ND32 for 37 mm

The K&F Concept hybrid 2-in-1 CPL + Solid Neutral Density ND2–ND32 for 37 mm lenses combines a circular polarizer with a stepped solid neutral density filter. The circular polarizer reduces unwanted reflections from non-metallic surfaces and improves color saturation, while the solid ND steps (ND2, ND4, ND8, ND16, ND32) give up to 5 stops of light reduction to enable longer exposures or wider apertures on compatible 37 mm thread lenses. The compact, single-piece design reduces the need to carry separate CPL and ND filters while maintaining repeatable results for landscape, long-exposure and portrait shooting.

Advantages

This hybrid filter integrates polarizing and neutral density functions in one slim, screw-in unit, saving space on the lens and simplifying filter changes. The CPL element helps control glare and enhances color rendering without affecting exposure, and the stepped ND options provide predictable light reduction settings for consistent results. The 37 mm thread size is suitable for small prime and compact lenses, and the filter construction is designed for straightforward attachment and stable optical alignment.

Suitable for

• Landscape photography to deepen skies and reduce water surface reflections
• Long-exposure shots such as smoothing water or capturing motion with up to 5 stops reduction
• Portraits when managing highlights and controlling depth of field in bright conditions
• Travel and street photography where compact, multipurpose accessories are preferred

Key specifications

• Filter type: hybrid circular polarizer (CPL) combined with solid neutral density (ND2–ND32)
• ND steps: ND2, ND4, ND8, ND16, ND32 (up to 5 stops)
• Mount / size: screw-in 37 mm thread
• Optical effect: reflection reduction, color saturation enhancement, controlled light attenuation
• Form factor: single-piece screw-in filter suitable for compact lens fronts

How to use

Screw the filter onto a lens with a 37 mm filter thread until finger-tight to avoid cross-threading. Rotate the CPL element to the desired angle while observing reflections or color saturation through the viewfinder or on the camera screen; stop when reflections are minimized or colors reach the intended richness. Select the appropriate ND step by aligning the filter markings (ND2 to ND32) to achieve the required exposure reduction; use longer shutter speeds or wider apertures as needed. Verify exposure using the camera meter and adjust ISO, aperture or shutter speed to compensate for the selected ND setting.

Usage recommendations

Use a tripod for long-exposure shots enabled by ND16 and ND32 settings to avoid camera shake; when combining strong polarizing effect with high ND stop values, check for potential color cast and compensate in-camera or during RAW processing.