K&F 4-in-1 Filter Kit 49mm — Nano-K, UV, CPL, ND4 (K&F SB7487)

The K&F 4-in-1 Filter Kit 49mm combines four commonly used optical filters in a compact set designed for lenses with a 49 mm thread. The kit contains a Nano-K coated protective filter, a UV filter, a circular polarizer (CPL) and an ND4 neutral density filter. Together these filters help protect the front element, reduce ultraviolet haze, control reflections and glare, and reduce exposure by approximately two stops for greater control over shutter speed and aperture in bright conditions.

Advantages

The Nano-K coating improves scratch and smudge resistance while maintaining light transmission and color neutrality. The UV filter reduces ultraviolet haze without significantly affecting color balance. The CPL filter cuts reflections from non-metallic surfaces and increases color saturation in skies and foliage. The ND4 neutral density filter reduces incoming light by two stops, enabling longer exposures or wider apertures in daylight. All four filters share the same 49 mm thread size for quick interchangeability and compact storage.

Suitable for

• Everyday photography with compact or prime 49 mm-thread lenses
• Landscape and outdoor scenes to enhance sky contrast and reduce haze
• Portraits and shallow depth-of-field work using ND4 to allow wider apertures in bright light
• Architectural and water photography where CPL removes unwanted reflections

Key specifications

• Filter thread diameter: 49 mm
• Included filter types: Nano-K protective, UV, Circular Polarizer (CPL), ND4 neutral density
• ND strength: 2 stops (ND4)
• Coating: Nano-K multi-coating for improved resistance to scratches and smudges
• Filter mount: slim profile threads to reduce vignetting on wide-angle lenses
• Material: optical glass elements with metal/aluminum ring construction

How to use

Screw the required filter onto the 49 mm front thread of the lens until snug; avoid overtightening. Use the UV or Nano-K protective filter as a permanent front element protector. Rotate the CPL filter while viewing through the viewfinder or live view to adjust polarization effect and reduce reflections. Attach the ND4 filter when you need to decrease exposure by two stops for longer shutter speeds or wider apertures in bright conditions. Remove and store unused filters in their protective case to prevent scratches and dust.

Usage recommendations

For best results, clean filters with a soft microfiber cloth and an appropriate lens cleaning solution. When shooting with the CPL, set exposure using manual or exposure lock after rotating the filter, as the polarization will change light transmission. Combine the ND4 with a tripod for longer exposures and confirm there is no vignetting on very wide-angle lenses; use the slim-profile filters first if vignetting appears.