ND Filters for Action Cameras (2026) — Who Actually Makes What, and Which Strength to Use

Every camera on this site was bought at retail. No affiliate links, no sponsored placements, no free review units. Full policy

You have seen the mountain bike edits where the trail flows past with a soft, liquid quality, and the surf clips where the lip of the wave has a slight smear to it. Then you watch your own footage back and every frame is knife-sharp and the motion stutters like a flipbook. That difference is almost never the camera. It is shutter speed, and the fix is a piece of dark glass.

Action cameras have almost no way to dump excess light. Nearly all of them have a fixed aperture — the Insta360 Ace Pro 2 is F2.6, the DJI Osmo Action 5 Pro f/2.8, the GoPro HERO13 Black f/2.5 — so in bright sun the only lever the camera has is shutter speed, and it pulls it hard: 1/2000s, 1/4000s, whatever it takes. Fast shutter speeds remove motion blur, and motion blur is what makes movement look like movement. The one current exception is the DJI Osmo Action 6, whose variable f/2–f/4 aperture gives it two stops of control before it has to touch the shutter — genuinely useful, and still not enough on snow at noon.

This guide does two things. First, the craft: how to pick an ND strength for a given frame rate and light level, and how to actually work with one in the field. Second, and more usefully, who makes filters for which camera — because this page previously recommended Freewell filters for the Insta360 Ace Pro 2 and Freewell does not make any. The availability table below is the part worth bookmarking.

What ND Filters Do

ND stands for neutral density. An ND filter is sunglasses for a camera: it cuts the amount of light reaching the sensor without changing the colour of that light. That is the whole mechanism. What it buys you is the freedom to use a slower shutter speed in conditions where the camera would otherwise refuse.

The reason you want a slower shutter is the 180-degree shutter rule: set your shutter speed to roughly double your frame rate. At 24fps that is 1/48s, at 30fps 1/60s, at 60fps 1/120s. Each frame is then exposed for about half the time it occupies, so moving objects smear across a little under half a frame's worth of travel. That is the amount of blur a century of cinema has trained everyone to read as natural motion. Shoot the same scene at 1/2000s and every frame is a crisp still; play twenty-four of them a second and the eye sees a sequence of stills rather than movement.

Here is the arithmetic problem. On a clear day, even at base ISO, a fixed-aperture action camera needs something between 1/1000s and 1/4000s to expose correctly. You want 1/60s. That is a gap of four to six stops, and there is no setting on the camera that closes it — ISO is already at its floor, and the aperture, on three of the four flagships, does not move. The filter is not a stylistic accessory in that situation; it is the only available exposure control.

There is one more thing an ND does that gets less attention, and it is the reason drone and FPV shooters treat filters as mandatory rather than optional. Propeller and motor vibration interacts with a rolling shutter to produce wavy "jello" distortion. A slower shutter adds enough per-frame blur to mask the artefact. Without an ND you cannot get the shutter slow enough, and there is no post-production fix.

ND Strength Cheat Sheet

ND filters are named for how much light they block. The naming is a factor, the stop count is what you reason with: ND4 blocks two stops, ND8 three, ND16 four, ND32 five, ND64 six. Each stop halves the light and therefore halves the shutter speed the camera needs.

Read the table by starting from what the camera tells you without a filter. Point it at your scene at base ISO with the shutter on auto, note the shutter speed it picks, then count the stops down to your target.

If you buy one filter, buy an ND16. It covers clear bright daylight at 24 or 30fps, which is the majority of the time anyone reaches for a filter at all. If you shoot 60fps you need one stop less, because your target shutter is 1/120 rather than 1/60 — so the daylight filter becomes ND8 and the snow filter becomes ND16.

If you buy a set, a four-pack of ND8/16/32/64 covers everything from bright overcast to noon on a glacier. Verified four-pack prices as of 1 September 2026 sit between $39.99 and $79.99 depending on brand and camera; the full table is in the brand section below. Buy the pack rather than accumulating singles — the per-filter cost is roughly half, and you will eventually want all four.

ND/PL Combos — Do You Need a Polariser?

Some ND filters add a polarising layer, sold as ND/PL. A polariser cuts reflections off non-metallic surfaces: glare on water, sheen on wet rock, reflections in a windscreen, the shine on wet leaves. It also deepens blue skies and increases apparent saturation, because a lot of what washes out a sky is scattered polarised light.

When it earns its place. Water sports of any kind — surfing, kayaking, paddleboarding, anything shot from or near the surface — where glare is the difference between seeing into the water and seeing a sheet of white. Driving footage through a windscreen, where a polariser is the only thing that removes your own dashboard from the shot. Forest riding after rain. Snow on a bright day. If you shoot any of those regularly, an ND/PL set is a better first purchase than a plain ND set.

The two costs. A polarising layer eats one to two stops of light on top of the ND rating, so an ND16/PL behaves more like a five or six stop filter — which is a problem the moment a cloud arrives, because you can find yourself pushed to a slow shutter or a raised ISO you did not want. And a polariser's effect depends on the angle between the lens and the light source; on a normal camera you rotate the filter to tune it, but on an action camera bolted to a helmet you cannot, so whatever effect you have is baked in and it changes every time you turn your head.

The recommendation. A plain ND set is the more versatile first purchase for most people, and an ND/PL set is the better one if water or snow is most of what you shoot. There is one relevant exception worth knowing: for the Insta360 Ace Pro 2, K&F Concept's verified four-pack is an ND/PL set at $44.99 — the polariser is not optional there, it is what is on the shelf. That is fine for the water and snow use cases and something to be aware of if you mostly shoot in forest.

Who Makes What: Brand Comparison

This is the section that matters, and it is the section the original version of this page got wrong. Filter availability for action cameras is patchy and brand-specific — several major filter brands make nothing at all for cameras you would assume are covered. Here is what we verified on 1 September 2026.

Three findings worth pulling out of that table.

Freewell does not make ND filters for the Insta360 Ace Pro 2. This page previously named Freewell as the top pick for that camera and described a magnetic adapter ring for it in detail. There is no such product. If you own an Ace Pro 2, your two real options are Insta360's own Ace Pro 2 ND Filter Set or K&F Concept's ND/PL four-pack at $44.99.

PGYTECH makes no ND filters for any of these four cameras. It makes mounts and cages, which are good, and the original page's "excellent magnetic set specifically for DJI at ~$39.99 for 3-pack" does not exist.

Only two manufacturers sell filters for their own cameras: Insta360 and GoPro. DJI does not. On the Action 6 and Action 5 Pro you are buying third-party glass whether you like it or not, which is a small but real ownership difference — a first-party set is the one place you can be confident the diameter, the thread and the lens-cover clearance were designed together.

A note on what this table no longer contains. The original ranked six brands on material, colour cast, durability and a rating out of ten, including a claim that Freewell's colour shift measured "under 100K across ND4 to ND32 on a colour checker". No such measurement was ever made for this site. We have replaced those columns with camera coverage and verified pricing, which is the information that actually changes which filter you can buy, and our ratings are stated as editorial judgements about coverage, price and availability rather than as lab results. Two brands the original scored — Telesin and Ulanzi — are absent because we have no verified availability data for them, not because they are bad.

Magnetic, Screw-On and Slip-On

How a filter attaches matters more than the brochure suggests, because the moment that decides it is always the same: light has changed, you are wearing gloves, and the camera is on a chest harness.

Magnetic. A metal base ring threads onto the camera once and stays there; filters snap on and off. This is the system to want if you shoot anything with variable light — riding out of forest into open ground, or a day where cloud keeps arriving. The trade-offs are a small amount of extra lens protrusion and the fact that the base ring can interfere with some lens caps and some housings.

Screw-on. The simplest and usually the cheapest. It is also the most secure, because nothing about it can be knocked loose. It is slow, and it is genuinely difficult with cold or wet hands — the failure mode is dropping a filter into snow or water while threading it. Choose it if you set one density at the start of a shoot and leave it there.

Slip-on. A friction fit over the lens housing, fast to change and needing no threading. Whether it exists for your camera depends entirely on the shape of the lens surround, which changes between generations.

Check the mounting system on the specific pack you are buying, not the brand. Mounting varies pack by pack and camera by camera, and we are not publishing per-brand mount claims we have not verified — the previous version of this page asserted a magnetic system for a camera the brand makes no filters for at all. One practical check before you buy: if you use a dive case or a protective housing, confirm the filter and the housing can coexist, because most cannot.

Variable NDs on Action Cameras

The short answer is no, and the reason is optical rather than commercial. A variable ND is two polarising layers rotating against each other. On the ultra-wide lenses action cameras use, that arrangement produces a dark X across the frame — cross-polarisation — and the wider the lens, the earlier it appears. On a 13mm-equivalent lens like the Insta360 Ace Pro 2's, it shows up at moderate densities, not just at the extremes.

Some manufacturers claim coatings that suppress it. Treat any such claim sceptically and test at your widest field of view before you rely on it, because the artefact is worst exactly where action cameras spend all their time. For now, fixed NDs are the right answer: a four-pack costs roughly what one decent variable ND costs, it has no moving parts to fail in water, and it cannot put an X in the middle of the one shot you cared about.

Recommendations by Camera

How to Use an ND Filter, Step by Step

Having the right filter is about a third of it. This is the order to work in.

1. Set your frame rate first. 24fps for cinematic delivery, 30fps for general video, 60fps for action and half-speed slow motion. Everything downstream depends on this number, because it sets your target shutter.
2. Lock the shutter to double the frame rate. 1/48 or 1/50 at 24fps, 1/60 at 30fps, 1/120 at 60fps. Use your camera's manual or pro exposure mode. If you leave the shutter on auto, the filter accomplishes nothing at all — the camera simply reopens the shutter to compensate and you have added dark glass for no reason. This is the most common mistake with ND filters and it is worth reading twice.
3. Set ISO limits, low. Minimum 100, maximum 400 in bright conditions, 800 if the light is going. You are trying to remove the camera's freedom to improvise.
4. Pick a density from the scene. Clear bright sun: ND16 at 24 or 30fps, ND8 at 60fps. Bright overcast: ND8, or ND4 at 60fps. Snow, sand or open water: ND32, or ND64 at noon. On the DJI Osmo Action 6, try f/4 first and drop one filter step.
5. Check with the histogram, not the screen. Screen brightness tells you about the screen. You want the exposure peak roughly central with nothing clipped hard against the right edge. Too bright at minimum ISO with the shutter locked: go up one density. Too dark: go down one.
6. Re-check every time the light changes materially. A cloud arriving, riding into forest, the sun dropping behind a ridge. This step is what makes a magnetic mount worth paying for, and it is the step everyone skips.

One practical habit worth building: shoot ten seconds of test footage after you fit a filter and actually look at it before the session that matters. A filter fitted slightly off-axis, or a base ring not fully seated, shows up immediately in a test clip and not at all on a settings screen.

Cleaning and Maintenance

An ND filter is the frontmost optical element in your system. A scratched or greasy one degrades every frame you shoot through it, and it will do that invisibly until you are grading.

• Use a lens pen or a blower, never your shirt. Fabric holds grit, and grit under pressure is how coatings get micro-scratched. Blow the loose material off first, then touch the glass.
• Microfibre for anything that remains, in circular strokes from the centre out, and keep the cloth in a sealed bag between uses. A dusty cloth is worse than no cloth.
• Rinse salt water off the same day. Dried salt crystals etch coatings permanently. Fresh water, then dry, then case.
• Store in the case the set came in. Loose filters in a backpack pocket will be scratched within a month. If your set did not come with a case, buy one; the padded slot design is not a luxury.
• Replace a scratched filter rather than living with it. A scratch near the centre shows as a soft patch or a flare source in every single shot, and at four-pack prices between $39.99 and $79.99 the maths is not close.

Frequently Asked Questions

More action camera guides

• related-card GoPro vs DJI vs Insta360 (2026) — Which flagship fits your workflow
• related-card Action Camera Settings Cheat Sheet — Eight scenarios, four cameras, every setting worth changing
• related-card DJI Osmo Action 6 Best Settings — What a variable aperture changes about filters
• related-card Underwater Shooting Guide — Red and magenta filters, depth by depth

Frequently asked questions

William Madden · Gear Reviewer & Action Sports Filmmaker

Eight years shooting action sports with GoPro, DJI and Insta360 cameras — powder days in Hokkaido, downhill in the Alps, surf in Portugal. Filter recommendations on this page are tied to verified availability and verified pricing checked on 1 September 2026; where we have no verified data for a camera, this page says so instead of filling the gap. More about me →