4 in x 5.65 in Square ND16 Neutral Density Filter - 4 Stops

In this review the focus is a compact square neutral density filter intended for matte box users who need precise exposure control. The 4 in x 5.65 in ND16 (4 stops) from K&F CONCEPT is best for videographers shooting 4K or 8K who want to slow shutter speed or open aperture without overexposure. The bottom line: it delivers neutral light reduction with impressively low reflectivity and high clarity, making it a practical, low-profile option to use with Tilta or SmallRig matte boxes.

Key Features

• Matte box compatibility: Designed to slide into standard matte boxes and filter frames, it fits Tilta, SmallRig and many mini matte boxes for flexible use across rigs.
• 4 stops ND: The ND16 density reduces light by four stops, allowing slower shutter speeds or wider apertures to achieve motion blur or shallow depth of field without overexposure.
• Imported HD optical glass: Double-sided polished glass preserves image clarity for 4K and 8K capture and minimizes the chance of a color cast in footage.
• Ultra-low reflectivity: Reflectivity controlled to about 0.2% reduces internal reflections and vignetting, helping maintain contrast and detail in highlights and shadows.
• 28 multi-layer coatings: Nanometer coatings on both sides make the filter scratch resistant, waterproof, oil proof and fingerprint resistant for reliable field use.
• Protective storage: The included leather-style filter bag keeps the glass safe between shoots and reduces risk of surface damage.

Who It's For

This filter suits independent filmmakers, documentary shooters and wedding videographers who use matte boxes and need a neutral, low-reflection ND to control exposure while keeping image quality high. It is especially helpful for operators who change lenses often, because the square format mounts in the matte box rather than screwing to each lens.

Photographers who do not use a matte box, or those needing variable ND control or denser reductions, should look elsewhere; this is a fixed 4-stop square plate meant for matte box systems rather than direct screw-in use.

Pros & Cons

Pros

• Neutral 4-stop reduction that enables cinematic shutter and aperture control without color cast.
• High clarity imported optical glass suitable for 4K and 8K workflows.
• Very low reflectivity and multi-layer coatings that reduce flare and resist scratches, water and fingerprints.

Cons

• Square plate must be mounted on a matte box and cannot be screwed directly to a lens, limiting use for shooters without a matte box.

Specifications

Our Verdict

The 4 in x 5.65 in ND16 square filter is a solid, affordable choice for filmmakers who work with matte boxes and demand neutral color and low reflection in high-resolution capture. It offers good build and optical qualities for the price and is a practical tool for anyone wanting consistent 4-stop exposure control without adding color cast or flare.

Frequently Asked Questions

Can this filter be mounted directly to a lens?
No, this square ND is intended to be used in a matte box or filter frame and does not screw directly onto lenses.

Is the filter suitable for 4K or 8K video?
Yes, the imported HD optical glass and double-sided polish are intended to preserve clarity for 4K and 8K shooting.

Does the coating resist fingerprints and water?
Yes, the 28 multi-layer nanometer coatings make the surface scratch resistant, waterproof and oil proof for easier cleaning and on-set use.