K&F Concept Variable ND Filter for DJI Osmo Action 3/4/5 Pro (ND2-32 & ND32-512)

If you shoot action footage outdoors, exposure changes can be relentless. A variable ND filter is designed to give you more control over shutter speed and aperture choice as light swings, without constantly swapping filters.

This K&F Concept variable ND set is built specifically for DJI Osmo Action 3, Action 4 and Action 5 Pro, and it’s aimed at drone aerial work and other bright-light situations where you want smoother motion blur or longer shutter speeds. It’s not the only way to manage exposure, but it’s a practical one if you want quick adjustments on location.

The essentials

A variable ND filter reduces the amount of light entering the camera, letting you keep exposure in check while you slow the shutter down (or open up your aperture, where applicable). In practice, that means you can tame harsh daylight and still get creative looks.

What stands out here is the extended range split across two variable ND options:

• ND2-32 covers roughly 1 to 5 f-stops, so it’s better for moderate lighting where you don’t need heavy reduction.
• ND32-512 covers roughly 5 to 9 f-stops, which fits brighter conditions and can support longer shutter speeds even in strong light.

On paper, that range split helps you avoid feeling stuck between “too little” and “too much” density.

What you’ll notice day to day

The filters use an instant push-on fit described as a snap-on mount that sits directly on the camera without removing the original protective filter. That small detail matters in real shooting: it’s quicker to adjust your setup when conditions change, and it reduces the faff that often comes with screw-on alternatives.

There’s also a multi-coating approach: high quality AGC optical glass with 28 layers of nano coating, aiming to reduce reflections. In bright scenes—sun reflections on water, glossy surfaces, or high-contrast skies—reduced reflections can help keep the image cleaner, though no filter fully eliminates flare in every situation.

Key specifications

• Type: Variable Neutral Density (ND) filter set
• Compatibility: DJI Osmo Action 3, Action 4, Action 5 Pro
• Included filters: ND2-32 and ND32-512
• ND2-32 density range: 1 to 5 f-stops
• ND32-512 density range: 5 to 9 f-stops
• Mounting: Instant push in / snap-on fit described as mounted directly without removing the original protective filter
• Glass/coating: AGC optical glass with 28 layers of nano coating
• Protection claims: Waterproof, scratch resistant, and resistant to mould and oil
• Testing note: Weight testing referenced to avoid compromising action camera performance

Where it shines (and where it may not)

A good fit if you regularly film outdoors, especially for drone aerial footage or any situation where lighting changes while you’re rolling. It also makes sense if you want more control over motion rendering—think smoother water and softened movement—without carrying multiple fixed ND filters.

It may not be the best choice if you expect a single filter to perfectly cover every lighting scenario. Variable ND filters can be very convenient, but the practical result still depends on how bright your location gets and what your camera settings allow. If you typically shoot only in stable low light, you might find the stronger ND32-512 range overkill.

Also, since this is a variable ND approach, you’ll still want to watch how your camera handles exposure across the full range—just because it’s “adjustable” doesn’t mean it will always look perfect at every position.

How to get the most from it

A quick example: you’re flying a drone over a river on a bright day, with reflections whipping around as you turn. Start with ND32-512 when the highlights are intense, then dial back towards ND2-32 as clouds pass or you move into shade. The aim is to keep shutter speed in a range that gives you the smoothing you want, while preventing overexposure.

For action cameras, the best results generally come from building a repeatable routine: check exposure, pick the density that prevents blown highlights, then fine-tune rather than constantly jumping to new settings.

Should you buy it?

It’s worth considering if you want an adjustable ND solution designed for DJI Osmo Action 3/4/5 Pro, with two variable ranges covering moderate to very bright light. The snap-on fit and the coating/protection claims are practical for field use, and the density spread helps you handle changing conditions without turning it into a filter swap marathon.

You may want to skip it if you mainly shoot in consistent indoor or low-light settings, or if you prefer a single, simple approach to filtering rather than dialling density during the shoot. And if your priority is absolute, no-compromise image control at every density setting, it’s wise to compare against other ND approaches—this set is positioned as a convenient variable range, not a specialist solution for every possible scenario.

Quick FAQ

Compatibility and fitting: will it work straight on?

It’s described as compatible with DJI Osmo Action 3, Action 4 and Action 5 Pro, using an instant push-in / snap-on fit that mounts directly without removing the original protective filter.

What do ND2-32 and ND32-512 cover?

ND2-32 is described for 1 to 5 f-stops (moderate lighting). ND32-512 is described for 5 to 9 f-stops (brighter conditions).

Does the coating help with reflections?

The filter is described as using AGC optical glass with 28 layers of nano coating to reduce reflections, which should help in harsh light, though flare can still depend on the scene.

Is it designed to be tough enough for action use?

The description includes waterproof, scratch resistant, and resistance to mould and oil, plus weight testing so it doesn’t compromise action camera performance on paper.

Is this a good choice for waterfalls and blurred motion?

The included description specifically points to creative effects like soft waterfalls or blurred movement, which aligns with the purpose of using stronger ND densities in bright light.