Circular Polarizing Filter K&F Nano-X MRC 40.5 mm (CPL)

The Circular Polarizing Filter K&F Nano-X MRC 40.5 mm (CPL) is an optical accessory designed for cameras with a 40.5 mm filter thread. It reduces unwanted reflections and glare from non-metallic surfaces, increases color saturation and contrast, and helps render skies and foliage with greater clarity. The filter uses multi-resistant coatings that make the glass easier to clean and more resistant to water, oil and fingerprints, while maintaining light transmission suitable for a single-stop exposure adjustment.

Advantages

This circular polarizer provides improved color depth and contrast for outdoor and landscape photography by selectively blocking polarized light. The multi-resistant coating (MRC) reduces surface contamination and simplifies maintenance without affecting image sharpness. A slim, low-profile metal frame minimizes vignetting on wide-angle lenses and allows smooth rotation for precise polarization control. The filter is lightweight and compatible with lenses that accept 40.5 mm screw-in filters.

Suitable for

• Landscape and nature photography
• Outdoor portraiture under bright sunlight
• Reducing reflections on water, glass and wet surfaces
• Enhancing sky contrast and cloud definition

Key specifications

• Filter type: Circular polarizer (CPL)
• Thread size: 40.5 mm
• Glass: multi-coated optical glass with anti-reflective and water/oil repellent properties
• Mount: slim-profile metal frame with rotatable front element
• Light loss: approximately 1 stop (typical for CPL filters)
• Weight: lightweight construction suitable for compact lens setups

How to use

Screw the filter onto the lens front thread until it is secure but not over-tightened. Rotate the outer ring while observing the viewfinder or live view to adjust the polarization effect; fine-tune until reflections are reduced and sky or foliage appearance meets your preference. Meter or check exposure as the CPL typically requires about one stop of additional exposure. Clean the coated surface with a soft microfiber cloth and appropriate lens cleaning solution if necessary.

Usage recommendations

For best results, use the CPL when the sun is at a 90-degree angle to the shooting direction to maximize polarization effects. Avoid stacking thick filters on wide-angle lenses to prevent vignetting. Store the filter in its protective case when not in use to preserve the coatings and threaded surfaces.